1. Overview of Hosts in Foreman
A host is any Linux client that Foreman manages. Hosts can be physical or virtual. Virtual hosts can be deployed on any platform supported by Foreman, such as KVM, VMware vSphere, OpenStack, Amazon EC2, Rackspace Cloud Services or Google Compute Engine.
Foreman enables host management at scale, including monitoring, provisioning, remote execution, configuration management, software management, and subscription management. You can manage your hosts from the Foreman web UI or from the command line.
In the Foreman web UI, you can browse all hosts recognized by Foreman server, grouped by type:
-
All Hosts - a list of all hosts recognized by Foreman server.
-
Discovered Hosts - a list of bare-metal hosts detected on the provisioning network by the Discovery plug-in.
-
Content Hosts - a list of hosts that manage tasks related to content and subscriptions.
-
Host Collections - a list of user-defined collections of hosts used for bulk actions such as errata installation.
To search for a host, type in the Search field, and use an asterisk (*) to perform a partial string search.
For example, if searching for a content host named dev-node.example.com
, click the Content Hosts page and type dev-node*
in the Search field.
Alternatively, *node*
will also find the content host dev-node.example.com.
Warning
|
Foreman server is listed as a host itself even if it is not self-registered. Do not delete Foreman server from the list of hosts. |
2. Administering Hosts
This chapter describes creating, registering, administering, and removing hosts.
2.1. Creating a Host in Foreman
Use this procedure to create a host in Foreman. To use the CLI instead of the web UI, see the CLI procedure.
-
In the Foreman web UI, click Hosts > Create Host.
-
On the Host tab, enter the required details.
-
Click the Ansible Roles tab, and from the Ansible Roles list, select one or more roles that you want to add to the host. Use the arrow icon to manage the roles that you add or remove.
-
On the Puppet Classes tab, select the Puppet classes you want to include.
-
On the Interfaces tab:
-
For each interface, click Edit in the Actions column and configure the following settings as required:
-
Type — For a Bond or BMC interface, use the Type list and select the interface type.
-
MAC address — Enter the MAC address.
-
DNS name — Enter the DNS name that is known to the DNS server. This is used for the host part of the FQDN.
-
Domain — Select the domain name of the provisioning network. This automatically updates the Subnet list with a selection of suitable subnets.
-
IPv4 Subnet — Select an IPv4 subnet for the host from the list.
-
IPv6 Subnet — Select an IPv6 subnet for the host from the list.
-
IPv4 address — If IP address management (IPAM) is enabled for the subnet, the IP address is automatically suggested. Alternatively, you can enter an address. The address can be omitted if provisioning tokens are enabled, if the domain does not mange DNS, if the subnet does not manage reverse DNS, or if the subnet does not manage DHCP reservations.
-
IPv6 address — If IP address management (IPAM) is enabled for the subnet, the IP address is automatically suggested. Alternatively, you can enter an address.
-
Managed — Select this check box to configure the interface during provisioning to use the Smart Proxy provided DHCP and DNS services.
-
Primary — Select this check box to use the DNS name from this interface as the host portion of the FQDN.
-
Provision — Select this check box to use this interface for provisioning. This means TFTP boot will take place using this interface, or in case of image based provisioning, the script to complete the provisioning will be executed through this interface. Note that many provisioning tasks, such as downloading RPMs by anaconda, Puppet setup in a
%post
script, will use the primary interface. -
Virtual NIC — Select this check box if this interface is not a physical device. This setting has two options:
-
Tag — Optionally set a VLAN tag. If unset, the tag will be the VLAN ID of the subnet.
-
Attached to — Enter the device name of the interface this virtual interface is attached to.
-
-
-
Click OK to save the interface configuration.
-
Optionally, click Add Interface to include an additional network interface. See Adding Network Interfaces for details.
-
Click Submit to apply the changes and exit.
-
-
On the Operating System tab, enter the required details. For Red Hat operating systems, select Synced Content for Media Selection. If you want to use non Red Hat operating systems, select All Media, then select the installation media from the Media Selection list. You can select a partition table from the list or enter a custom partition table in the Custom partition table field. You cannot specify both.
-
On the Parameters tab, click Add Parameter to add any parameter variables that you want to pass to job templates at run time. This includes all Puppet Class, Ansible playbook parameters and host parameters that you want to associate with the host. To use a parameter variable with an Ansible job template, you must add a Host Parameter.
-
On the Additional Information tab, enter additional information about the host.
-
Click Submit to complete your provisioning request.
-
To create a host associated to a host group, enter the following command:
# hammer host create \ --name "host_name" \ --hostgroup "hostgroup_name" \ --interface="primary=true, \ provision=true, \ mac=mac_address, \ ip=ip_address" \ --organization "Your_Organization" \ --location "Your_Location" \ --ask-root-password yes
This command prompts you to specify the root password. It is required to specify the host’s IP and MAC address. Other properties of the primary network interface can be inherited from the host group or set using the
--subnet
, and--domain
parameters. You can set additional interfaces using the--interface
option, which accepts a list of key-value pairs. For the list of available interface settings, enter thehammer host create --help
command.
2.2. Changing a Module Stream for a Host
If you have a Red Hat Enterprise Linux 8 or clone operating system host, you can modify the module stream for the repositories you install.
After you create the host, you can enable, disable, install, update, and remove module streams from your host in the Foreman web UI.
-
In the Foreman web UI, navigate to Hosts > Content Hosts and click the name of the host that contains the modules you want to change.
-
Click the Module Streams tab.
-
From the Available Module Streams list, locate the module that you want to change. You can use the Filter field to refine the list entries. You can also use the Filter Status list to search for modules with a specific status.
-
From the Actions list, select the change that you want to make to the module.
-
In the Job Invocation window, ensure that the job information is accurate. Change any details that you require, and then click Submit.
2.3. Creating a Host Group
If you create a high volume of hosts, many of the hosts can have common settings and attributes. Adding these settings and attributes for every new host is time consuming. If you use host groups, you can apply common attributes to hosts that you create.
A host group functions as a template for common host settings, containing many of the same details that you provide to hosts. When you create a host with a host group, the host inherits the defined settings from the host group. You can then provide additional details to individualize the host.
To use the CLI instead of the web UI, see the CLI procedure.
You can create a hierarchy of host groups. Aim to have one base level host group that represents all hosts in your organization and provide general settings, and then nested groups to provide specific settings. For example, you can have a base level host group that defines the operating system, and two nested host groups that inherit the base level host group:
-
Hostgroup:
Base
(Red Hat Enterprise Linux 7.6)-
Hostgroup:
Webserver
(applies thehttpd
Puppet class)-
Host:
webserver1.example.com
(web server) -
Host:
webserver2.example.com
(web server)
-
-
Hostgroup:
Storage
(applies thenfs
Puppet class)-
Host:
storage1.example.com
(storage server) -
Host:
storage2.example.com
(storage server)
-
-
Host:
custom.example.com
(custom host)
-
In this example, all hosts use Red Hat Enterprise Linux 7.6 as their operating system because of their inheritance of the Base
host group.
The two web server hosts inherit the settings from the Webserver
host group, which includes the httpd
Puppet class and the settings from the Base
host group.
The two storage servers inherit the settings from the Storage
host group, which includes the nfs
Puppet class and the settings from the Base
host group.
The custom host only inherits the settings from the Base
host group.
-
In the Foreman web UI, navigate to Configure > Host Groups and click Create Host Group.
-
If you have an existing host group that you want to inherit attributes from, you can select a host group from the Parent list. If you do not, leave this field blank.
-
Enter a Name for the new host group.
-
Enter any further information that you want future hosts to inherit.
-
Click the Ansible Roles tab, and from the Ansible Roles list, select one or more roles that you want to add to the host. Use the arrow icon to manage the roles that you add or remove.
-
Click the additional tabs and add any details that you want to attribute to the host group.
NotePuppet fails to retrieve the Puppet CA certificate while registering a host with a host group associated with a Puppet environment created inside a
Production
environment.To create a suitable Puppet environment to be associated with a host group, manually create a directory and change the owner:
# mkdir /etc/puppetlabs/code/environments/example_environment # chown apache /etc/puppetlabs/code/environments/example_environment
-
Click Submit to save the host group.
-
Create the host group with the
hammer hostgroup create
command. For example:# hammer hostgroup create --name "Base" \ --lifecycle-environment "Production" --content-view "Base" \ --puppet-environment "production" --content-source-id 1 \ --puppet-ca-proxy-id 1 --puppet-proxy-id 1 --domain "example.com" \ --subnet `ACME's Internal Network` --architecture "x86_64" \ --operatingsystem "RedHat 7.2" --medium-id 9 \ --partition-table "Kickstart default" --root-pass "p@55w0rd!" \ --locations "New York" --organizations "ACME"
2.4. Creating a Host Group for Each LifeCycle Environment
Use this procedure to create a host group for the Library lifecycle environment and add nested host groups for other lifecycle environments.
To create a host group for each life cycle environment, run the following Bash script:
MAJOR="7"
ARCH="x86_64"
ORG="Your Organization"
LOCATIONS="Your Location"
PTABLE_NAME="Kickstart default"
DOMAIN="example.com"
hammer --output csv --no-headers lifecycle-environment list --organization "${ORG}" | cut -d ',' -f 2 | while read LC_ENV; do
[[ ${LC_ENV} == "Library" ]] && continue
hammer hostgroup create --name "rhel-${MAJOR}server-${ARCH}-${LC_ENV}" \
--architecture "${ARCH}" \
--partition-table "${PTABLE_NAME}" \
--domain "${DOMAIN}" \
--organizations "${ORG}" \
--query-organization "${ORG}" \
--locations "${LOCATIONS}" \
--lifecycle-environment "${LC_ENV}"
done
2.5. Changing the Group of a Host
Use this procedure to change the group of a host.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Select the check box of the host you want to change.
-
From the Select Action list, select Change Group. A new option window opens.
-
From the Host Group list, select the group that you want for your host.
-
Click Submit.
2.6. Changing the Environment of a Host
Use this procedure to change the environment of a host.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Select the check box of the host you want to change.
-
From the Select Action list, select Change Environment. A new option window opens.
-
From the Environment list, select the new environment for your host.
-
Click Submit.
2.7. Changing the Managed Status of a Host
Hosts provisioned by Foreman are Managed by default. When a host is set to Managed, you can configure additional host parameters from Foreman server. These additional parameters are listed on the Operating System tab. If you change any settings on the Operating System tab, they will not take effect until you set the host to build and reboot it.
If you need to obtain reports about configuration management on systems using an operating system not supported by Foreman, set the host to Unmanaged.
Use this procedure to switch a host between Managed and Unmanaged status.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Select the host.
-
Click Edit.
-
Click Manage host or Unmanage host to change the host’s status.
-
Click Submit.
2.8. Assigning a Host to a Specific Organization
Use this procedure to assign a host to a specific organization. For general information about organizations and how to configure them, see Managing Organizations in the Content Management Guide.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Select the check box of the host you want to change.
-
From the Select Action list, select Assign Organization. A new option window opens.
-
From the Select Organization list, select the organization that you want to assign your host to. Select the check box Fix Organization on Mismatch.
NoteA mismatch happens if there is a resource associated with a host, such as a domain or subnet, and at the same time not associated with the organization you want to assign the host to. The option Fix Organization on Mismatch will add such a resource to the organization, and is therefore the recommended choice. The option Fail on Mismatch will always result in an error message. For example, reassigning a host from one organization to another will fail, even if there is no actual mismatch in settings.
-
Click Submit.
2.9. Assigning a Host to a Specific Location
Use this procedure to assign a host to a specific location. For general information about locations and how to configure them, see Creating a Location in the Content Management Guide.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Select the check box of the host you want to change.
-
From the Select Action list, select Assign Location. A new option window opens.
-
Navigate to the Select Location list and choose the location that you want for your host. Select the check box Fix Location on Mismatch.
NoteA mismatch happens if there is a resource associated with a host, such as a domain or subnet, and at the same time not associated with the location you want to assign the host to. The option Fix Location on Mismatch will add such a resource to the location, and is therefore the recommended choice. The option Fail on Mismatch will always result in an error message. For example, reassigning a host from one location to another will fail, even if there is no actual mismatch in settings.
-
Click Submit.
2.10. Removing a Host from Foreman
Use this procedure to remove a host from Foreman.
-
In the Foreman web UI, navigate to Hosts > All hosts or Hosts > Content Hosts. Note that there is no difference from what page you remove a host, from All hosts or Content Hosts. In both cases, Foreman removes a host completely.
-
Select the hosts that you want to remove.
-
From the Select Action list, select Delete Hosts.
-
Click Submit to remove the host from Foreman permanently.
Warning
|
By default, the To delete a virtual machine on the compute resource, navigate to Administer > Settings and select the Provisioning tab.
Setting |
-
In the Foreman web UI, navigate to Hosts > All Hosts and select the check box to the left of the hosts to be disassociated.
-
From the Select Action list, select the Disassociate Hosts button.
-
Optionally, select the check box to keep the hosts for future action.
-
Click Submit.
3. Registering a Host to Foreman Using the Global Registration Template
Use the following procedure to register a host to Foreman.
With this registration method you can register hosts to Foreman by generating a curl
command on Foreman and running this command on hosts.
This method uses the global registration template that gives you complete control over the process of the host registration.
Note that you can extend the parameters by plug-ins. For more information, see How to Create a Plugin.
-
The Foreman user that generates the
curl
command must have thecreate_hosts
permission. -
You must have root privileges on the host that you want to register.
-
In the Foreman web UI, navigate to Hosts > Provisioning Templates, find the Linux registration default template and click it.
-
Click the Association tab.
-
Ensure that the operating system that you want to register is in the Selected items column.
-
Click Submit.
-
Navigate to Hosts > Operating Systems and click the operating system that you want to register.
-
Click the Templates tab.
-
From the Registration template list, ensure that Linux registration default is selected.
-
Click Submit.
-
Navigate to Hosts > All Hosts > Register Host.
-
Optional: If you want to register hosts through Smart Proxy, ensure that the Registration feature is enabled on this Smart Proxy.
Navigate to Infrastructure > Smart Proxies, click the Smart Proxy that you want to use, and locate the Registration feature in the Active features list.
Optional: If the Registration feature is not enabled on your Smart Proxy, enter the following command on the Smart Proxy to enable it:
# foreman-installer --foreman-proxy-registration \ --foreman-proxy-templates \ --foreman-proxy-template-url 'http://smartproxy.example.com'
-
Optional: From the Host Group list, select the host group to associate the hosts with.
-
From the Operating System list, select the operating system of hosts that you want to register.
-
From the Smart Proxy list, select the Smart Proxy to register hosts through. You must select the internal Smart Proxy if you do not want to use an external Smart Proxy.
-
From the Remote Execution list, select whether you want to deploy Foreman SSH keys to hosts or not.
-
Optional: Foreman uses the JSON Web Tokens (JWT) for authentication. The duration of this token defines how long the generated
curl
command works. If you want to change the duration of the token, enter the required duration to the Token lifetime (hours) field. You can set the duration to any number of hours.Note that Foreman uses the permissions of the user who generates the
curl
command for authorization of hosts. If the user loses or gains additional permissions, the permissions of the JWT change too. Therefore, do not delete, block, or change permissions of the user during the token duration. -
Optional: In the Remote Execution Interface field, enter a network interface that hosts must use for the SSH connection. If you keep this field blank, Foreman uses the default network interface.
-
Optional: This step is for the Katello users only. If you register RHEL or CentOS hosts, in the Activation Key(s) field, enter one or more activation keys to assign to registered hosts.
-
Click Generate command.
-
Copy the generated
curl
command to enter it on the hosts. -
Configure hosts with the CA certificate with one of the following methods:
-
Add the
--insecure
option to thecurl
command. This makes the first call insecure, however, during this first call, hosts download the CA file from Foreman. Hosts will use this CA file to connect to Foreman with all future calls making them secure.If an attacker, located in the network between Foreman and a host, fetches the CA file from the first insecure call, the attacker will be able to access the content of the API calls to and from the registered host and the JWT. Therefore, if you have chosen to deploy SSH keys during registration, the attacker will be able to access the host using the SSH key. The following is an example of the
curl
command with the--insecure
option:curl -X GET --insecure https://foreman.example.com/register...
-
If you do not want to call the
curl
command with the--insecure
option, you can manually copy and install the CA file on each host.To do this find where Foreman stores the CA file by navigating to Administer > Settings > Authentication and locating the value for the SSL CA file setting.
Copy the CA file to the
/etc/pki/ca-trust/source/anchors/
directory on hosts and enter the following commands:# update-ca-trust enable # update-ca-trust
-
-
On the hosts that you want to register, enter the
curl
command asroot
.
3.1. Customizing the Global Registration and Host Registration Templates
Use information in this section if you want to customize the registration process.
Note that all default templates in Foreman are locked. If you want to customize the registration process, you need to clone the default templates and edit the clones. Then, change the Default Global registration template setting in Administer > Settings > Provisioning to point to your custom Global Registration template. Change the Registration template setting in the operating system settings to point to your custom Linux registration default template.
The registration process uses the following registration templates:
-
The Global Registration template contains steps for registering hosts to Foreman. This template renders when hosts access the
/register
endpoint. -
The Linux registration default template contains steps for configuring hosts after they are registered.
You can configure the following global parameters by navigating to Configure > Global Parameters:
-
The
host_registration_remote_execution
parameter is used in theremote_execution_ssh_keys
snippet, the default value istrue
. -
The
host_registration_insights
parameter is used in theinsights
snippet, the default value isfalse
.
The remote_execution_ssh_keys
snippet is used in the Linux registration default template.
It deploys SSH keys to the host only when the host_registration_remote_execution
parameter is true
.
The insights
snippet is used in the Linux registration default template.
It downloads and installs the Red Hat Insights client when global parameter host_registration_insights
is set to true.
This table describes what variables are used in the Global Registration
template.
Variable | Command argument | Description |
---|---|---|
|
none |
Current authenticated user object. |
|
|
If |
|
|
If |
|
|
Host group of the host. |
|
|
Host operating system. |
|
|
Override the value of the |
|
|
Override the value of |
|
|
Set default interface of host for the remote execution. |
|
|
The Host activation keys snippet is for Katello users only. |
|
none |
URL for the |
4. Adding Network Interfaces
Foreman supports specifying multiple network interfaces for a single host. You can configure these interfaces when creating a new host as described in Creating a Host in Foreman or when editing an existing host.
There are several types of network interfaces that you can attach to a host. When adding a new interface, select one of:
-
Interface: Allows you to specify an additional physical or virtual interface. There are two types of virtual interfaces you can create. Use VLAN when the host needs to communicate with several (virtual) networks using a single interface, while these networks are not accessible to each other. Use alias to add an additional IP address to an existing interface.
For more information about adding a physical interface, see Adding a Physical Interface.
For more information about adding a virtual interface, see Adding a Virtual Interface.
-
Bond: Creates a bonded interface. NIC bonding is a way to bind multiple network interfaces together into a single interface that appears as a single device and has a single MAC address. This enables two or more network interfaces to act as one, increasing the bandwidth and providing redundancy. See Adding a Bonded Interface for details.
-
BMC: Baseboard Management Controller (BMC) allows you to remotely monitor and manage the physical state of machines. For more information about BMC, see Enabling Power Management on Managed Hosts in Installing Foreman 2.4 server on Enterprise Linux. For more information about configuring BMC interfaces, see Adding a Baseboard Management Controller (BMC) Interface.
Note
|
Additional interfaces have the Managed flag enabled by default, which means the new interface is configured automatically during provisioning by the DNS and DHCP Smart Proxy servers associated with the selected subnet.
This requires a subnet with correctly configured DNS and DHCP Smart Proxy servers.
If you use a Kickstart method for host provisioning, configuration files are automatically created for managed interfaces in the post-installation phase at |
Note
|
Virtual and bonded interfaces currently require a MAC address of a physical device. Therefore, the configuration of these interfaces works only on bare-metal hosts. |
4.1. Adding a Physical Interface
Use this procedure to add an additional physical interface to a host.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Click Edit next to the host you want to edit.
-
On the Interfaces tab, click Add Interface.
-
Keep the Interface option selected in the Type list.
-
Specify a MAC address. This setting is required.
-
Specify the Device Identifier, for example eth0. The identifier is used to specify this physical interface when creating bonded interfaces, VLANs, and aliases.
-
Specify the DNS name associated with the host’s IP address. Foreman saves this name in Smart Proxy server associated with the selected domain (the "DNS A" field) and Smart Proxy server associated with the selected subnet (the "DNS PTR" field). A single host can therefore have several DNS entries.
-
Select a domain from the Domain list. To create and manage domains, navigate to Infrastructure > Domains.
-
Select a subnet from the Subnet list. To create and manage subnets, navigate to Infrastructure > Subnets.
-
Specify the IP address. Managed interfaces with an assigned DHCP Smart Proxy server require this setting for creating a DHCP lease. DHCP-enabled managed interfaces are automatically provided with a suggested IP address.
-
Select whether the interface is Managed. If the interface is managed, configuration is pulled from the associated Smart Proxy server during provisioning, and DNS and DHCP entries are created. If using kickstart provisioning, a configuration file is automatically created for the interface.
-
Select whether this is the Primary interface for the host. The DNS name from the primary interface is used as the host portion of the FQDN.
-
Select whether this is the Provision interface for the host. TFTP boot takes place using the provisioning interface. For image-based provisioning, the script to complete the provisioning is executed through the provisioning interface.
-
Select whether to use the interface for Remote execution.
-
Leave the Virtual NIC check box clear.
-
Click OK to save the interface configuration.
-
Click Submit to apply the changes to the host.
4.2. Adding a Virtual Interface
Use this procedure to configure a virtual interface for a host. This can be either a VLAN or an alias interface.
An alias interface is an additional IP address attached to an existing interface.
An alias interface automatically inherits a MAC address from the interface it is attached to; therefore, you can create an alias without specifying a MAC address.
The interface must be specified in a subnet with boot mode set to static
.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Click Edit next to the host you want to edit.
-
On the Interfaces tab, click Add Interface.
-
Keep the Interface option selected in the Type list.
-
Specify the general interface settings. The applicable configuration options are the same as for the physical interfaces described in Adding a Physical Interface.
Specify a MAC address for managed virtual interfaces so that the configuration files for provisioning are generated correctly. However, a MAC address is not required for virtual interfaces that are not managed.
If creating a VLAN, specify ID in the form of eth1.10 in the Device Identifier field. If creating an alias, use ID in the form of eth1:10.
-
Select the Virtual NIC check box. Additional configuration options specific to virtual interfaces are appended to the form:
-
Tag: Optionally set a VLAN tag to trunk a network segment from the physical network through to the virtual interface. If you do not specify a tag, managed interfaces inherit the VLAN tag of the associated subnet. User-specified entries from this field are not applied to alias interfaces.
-
Attached to: Specify the identifier of the physical interface to which the virtual interface belongs, for example eth1. This setting is required.
-
-
Click OK to save the interface configuration.
-
Click Submit to apply the changes to the host.
4.3. Adding a Bonded Interface
Use this procedure to configure a bonded interface for a host. To use the CLI instead of the web UI, see the CLI procedure.
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Click Edit next to the host you want to edit.
-
On the Interfaces tab, click Add Interface.
-
Select Bond from the Type list. Additional type-specific configuration options are appended to the form.
-
Specify the general interface settings. The applicable configuration options are the same as for the physical interfaces described in Adding a Physical Interface.
Bonded interfaces use IDs in the form of bond0 in the Device Identifier field.
A single MAC address is sufficient.
-
Specify the configuration options specific to bonded interfaces:
-
Mode: Select the bonding mode that defines a policy for fault tolerance and load balancing. See Bonding Modes Available in Foreman for a brief description of each bonding mode.
-
Attached devices: Specify a comma-separated list of identifiers of attached devices. These can be physical interfaces or VLANs.
-
Bond options: Specify a space-separated list of configuration options, for example miimon=100. See the Red Hat Enterprise Linux 7 Networking Guide for details of the configuration options you can specify for the bonded interface.
-
-
Click OK to save the interface configuration.
-
Click Submit to apply the changes to the host.
-
To create a host with a bonded interface, enter the following command:
# hammer host create --name bonded_interface \ --hostgroup-id 1 \ --ip=192.168.100.123 \ --mac=52:54:00:14:92:2a \ --subnet-id=1 \ --managed true \ --interface="identifier=eth1, \ mac=52:54:00:62:43:06, \ managed=true, \ type=Nic::Managed, \ domain_id=1, \ subnet_id=1" \ --interface="identifier=eth2, \ mac=52:54:00:d3:87:8f, \ managed=true, \ type=Nic::Managed, \ domain_id=1, \ subnet_id=1" \ --interface="identifier=bond0, \ ip=172.25.18.123, \ type=Nic::Bond, \ mode=active-backup, \ attached_devices=[eth1,eth2], \ managed=true, \ domain_id=1, \ subnet_id=1" \ --organization "Your_Organization" \ --location "Your_Location" \ --ask-root-password yes
Bonding Mode | Description |
---|---|
balance-rr |
Transmissions are received and sent sequentially on each bonded interface. |
active-backup |
Transmissions are received and sent through the first available bonded interface. Another bonded interface is only used if the active bonded interface fails. |
balance-xor |
Transmissions are based on the selected hash policy. In this mode, traffic destined for specific peers is always sent over the same interface. |
broadcast |
All transmissions are sent on all bonded interfaces. |
802.a3 |
Creates aggregation groups that share the same settings. Transmits and receives on all interfaces in the active group. |
balance-tlb |
The outgoing traffic is distributed according to the current load on each bonded interface. |
balance-alb |
Receive load balancing is achieved through Address Resolution Protocol (ARP) negotiation. |
4.4. Adding a Baseboard Management Controller (BMC) Interface
Use this procedure to configure a baseboard management controller (BMC) interface for a host that supports this feature.
-
The
ipmitool
package is installed. -
You know the MAC address, IP address, and other details of the BMC interface on the host, and the appropriate credentials for that interface.
NoteYou only need the MAC address for the BMC interface if the BMC interface is managed, so that it can create a DHCP reservation.
-
Enable BMC on the Smart Proxy server if it is not already enabled:
-
Configure BMC power management on Smart Proxy server by running the
foreman-installer
script with the following options:# foreman-installer --foreman-proxy-bmc=true \ --foreman-proxy-bmc-default-provider=ipmitool
-
In the Foreman web UI, navigate to Infrastructure > Smart Proxies.
-
From the list in the Actions column, click Refresh. The list in the Features column should now include BMC.
-
-
In the Foreman web UI, navigate to Hosts > All hosts.
-
Click Edit next to the host you want to edit.
-
On the Interfaces tab, click Add Interface.
-
Select BMC from the Type list. Type-specific configuration options are appended to the form.
-
Specify the general interface settings. The applicable configuration options are the same as for the physical interfaces described in Adding a Physical Interface.
-
Specify the configuration options specific to BMC interfaces:
-
Username and Password: Specify any authentication credentials required by BMC.
-
Provider: Specify the BMC provider.
-
-
Click OK to save the interface configuration.
-
Click Submit to apply the changes to the host.
5. Upgrading Hosts from RHEL 7 to RHEL 8
You can use a job template to upgrade your Red Hat Enterprise Linux 7 hosts to Red Hat Enterprise Linux 8.
-
Ensure that your RHEL 7 hosts meet the requirements for the upgrade to RHEL 8. For more information, see Planning an upgrade in the Upgrading from RHEL 7 to RHEL 8 guide.
-
Prepare your hosts for the upgrade. For more information, see Preparing a RHEL 7 system for the upgrade in the Upgrading from RHEL 7 to RHEL 8 guide.
-
Enable remote execution feature on Foreman. For more information, see Configuring and Setting up Remote Jobs.
-
Distribute Foreman SSH keys to the hosts that you want to upgrade. For more information, see Distributing SSH Keys for Remote Execution.
-
On Foreman, enable the
foreman_plugin_leapp
puppet module:# foreman-installer --enable-foreman-plugin-leapp
-
In the Foreman web UI, navigate to Hosts > All Hosts.
-
Select the hosts that you want to upgrade to Red Hat Enterprise Linux 8.
-
In the upper right of the Hosts window, from the Select Action list, select Preupgrade check with Leapp.
-
Click Submit to start the pre-upgrade check.
-
When the check is finished, click the Leapp preupgrade report tab to see if LEAPP has found any issues on RHEL 7 hosts. Issues that have the Inhibitor flag are considered crucial and are likely to break the upgrade procedure. Some issues might have documentation linked that describe how to fix them.
-
Optional: If you have issues that have commands associated with them, you can fix them with a remote job. To do that, select these issues, click the Fix Selected button, and submit the job.
-
After you fixed the issues, click the Rerun button, and then click Submit to run the pre-upgrade check again to verify that your RHEL 7 hosts do not have any issues and are ready to be upgraded.
-
When your systems are ready for the upgrade, click the Run Upgrade button and click submit to start the upgrade.
6. Host Management and Monitoring Using Cockpit
Cockpit is an interactive web interface that you can use to perform actions and monitor Red Hat Enterprise Linux hosts. You can enable a remote-execution feature to integrate Foreman with Cockpit. When you install Cockpit on a host that you manage with Foreman, you can view the Cockpit dashboards of that host from within the Foreman web UI. You can also use the features that are integrated with Cockpit, for example, Lorax Composer.
6.1. Integrating Foreman with Cockpit
By default, Cockpit integration is disabled in Foreman. If you want to access Cockpit features for your hosts from within Foreman, you must first enable Cockpit integration on Foreman server.
-
On Foreman server, run
foreman-installer
with the--enable-foreman-plugin-remote-execution-cockpit
option:# foreman-installer --enable-foreman-plugin-remote-execution-cockpit
6.2. Managing and Monitoring Hosts Using Cockpit
You can access the Cockpit web UI through the Foreman web UI and use the functionality to manage and monitor hosts in Foreman.
-
Cockpit is enabled in Foreman.
-
Cockpit is installed on the host that you want to view:
-
For more information see Running Cockpit.
-
-
Foreman or Smart Proxy can authenticate to the host with SSH keys. For more information, Distributing SSH Keys for Remote Execution.
-
In the Foreman web UI, navigate to Hosts > All Hosts and select the host that you want to manage and monitor with Cockpit.
-
In the upper right of the host window, click Web Console.
You can now access the full range of features available for host monitoring and management, for example, Lorax Composer, through the Cockpit.
7. Using Report Templates to Monitor Hosts
You can use report templates to query Foreman data to obtain information about, for example, host status, registered hosts, applicable errata, applied errata, subscription details, and user activity. You can use the report templates that ship with Foreman or write your own custom report templates to suit your requirements. The reporting engine uses the embedded Ruby (ERB) syntax. For more information about writing templates and ERB syntax, see Template Writing Reference.
You can create a template, or clone a template and edit the clone. For help with the template syntax, click a template and click the Help tab.
7.1. Generating Host Monitoring Reports
To view the report templates, in the Foreman web UI, navigate to Monitor > Report Templates.
To schedule reports, you can configure a cron job or use the Foreman web UI.
-
In the Foreman web UI, navigate to Monitor > Report Templates.
-
To the right of the report template that you want to use, click Generate.
-
Optional: To schedule a report, to the right of the Generate at field, click the icon to select the date and time you want to generate the report at.
-
Optional: To send a report to an e-mail address, select the Send report via e-mail check box, and in the Deliver to e-mail addresses field, enter the required e-mail address.
-
Optional: Apply search query filters. To view all available results, do not populate the filter field with any values.
-
Click Submit. A CSV file that contains the report is downloaded. If you have selected the Send report via e-mail check box, the host monitoring report is sent to your e-mail address.
To generate a report, complete the following steps:
-
List all available report templates:
# hammer report-template list
-
Generate a report:
# hammer report-template generate --id template ID
This command waits until the report fully generates before completing. If you want to generate the report as a background task, you can use the
hammer report-template schedule
command.
7.2. Creating a Report Template
In Foreman, you can create a report template and customize the template to suit your requirements. You can import existing report templates and further customize them with snippets and template macros.
Report templates use Embedded Ruby (ERB) syntax. To view information about working with ERB syntax and macros, in the Foreman web UI, navigate to Monitor > Report Templates, and click Create Template, and then click the Help tab.
When you create a report template in Foreman, safe mode is enabled by default. For more information about safe mode, see Report Template Safe Mode.
For more information about writing templates, see the Template Writing Reference.
For more information about macros you can use in report templates, see Templates Macros.
-
In the Foreman web UI, navigate to Monitor > Report Templates, and click Create Template.
-
In the Name field, enter a unique name for your report template.
-
If you want the template to be available to all locations and organizations, select Default.
-
Create the template directly in the template editor or import a template from a text file by clicking Import. For more information about importing templates, see Importing Report Templates.
-
Optional: In the Audit Comment field, you can add any useful information about this template.
-
Click the Input tab, and in the Name field, enter a name for the input that you can reference in the template in the following format:
input('name')
. Note that you must save the template before you can reference this input value in the template body. -
Select whether the input value is mandatory. If the input value is mandatory, select the Required check box.
-
From the Value Type list, select the type of input value that the user must input.
-
Optional: If you want to use facts for template input, select the Advanced check box.
-
Optional: In the Options field, define the options that the user can select from. If this field remains undefined, the users receive a free-text field in which they can enter the value they want.
-
Optional: In the Default field, enter a value, for example, a host name, that you want to set as the default template input.
-
Optional: In the Description field, you can enter information that you want to display as inline help about the input when you generate the report.
-
Optional: Click the Type tab, and select whether this template is a snippet to be included in other templates.
-
Click the Location tab and add the locations where you want to use the template.
-
Click the Organizations tab and add the organizations where you want to use the template.
-
Click Submit to save your changes.
7.3. Exporting Report Templates
You can export report templates that you create in Foreman.
-
In the Foreman web UI, navigate to Monitor > Report Templates.
-
Locate the template that you want to export, and from the list in the Actions column, select Export.
-
Repeat this action for every report template that you want to download.
An .erb
file that contains the template downloads.
-
To view the report templates available for export, enter the following command:
# hammer report-template list
Note the template ID of the template that you want to export in the output of this command.
-
To export a report template, enter the following command:
# hammer report-template dump --id template_ID > example_export.erb
7.4. Exporting Report Templates Using the Foreman API
You can use the Foreman report_templates
API to export report templates from Foreman.
For more information about using the Foreman API, see the API Guide.
-
Use the following request to retrieve a list of available report templates:
Example request:$ curl --insecure --user admin:redhat \ --request GET \ --config https://foreman.example.com/api/report_templates \ | json_reformat
In this example, the
json_reformat
tool is used to format the JSON output.Example response:{ "total": 6, "subtotal": 6, "page": 1, "per_page": 20, "search": null, "sort": { "by": null, "order": null }, "results": [ { "created_at": "2019-11-20 17:49:52 UTC", "updated_at": "2019-11-20 17:49:52 UTC", "name": "Applicable errata", "id": 112 }, { "created_at": "2019-11-20 17:49:52 UTC", "updated_at": "2019-11-20 17:49:52 UTC", "name": "Applied Errata", "id": 113 }, { "created_at": "2019-11-30 16:15:24 UTC", "updated_at": "2019-11-30 16:15:24 UTC", "name": "Hosts - complete list", "id": 158 }, { "created_at": "2019-11-20 17:49:52 UTC", "updated_at": "2019-11-20 17:49:52 UTC", "name": "Host statuses", "id": 114 }, { "created_at": "2019-11-20 17:49:52 UTC", "updated_at": "2019-11-20 17:49:52 UTC", "name": "Registered hosts", "id": 115 }, { "created_at": "2019-11-20 17:49:52 UTC", "updated_at": "2019-11-20 17:49:52 UTC", "name": "Subscriptions", "id": 116 } ] }
-
Note the
id
of the template that you want to export, and use the following request to export the template:Example request:$ curl --insecure --output /tmp/_Example_Export_Template.erb_ \ --user admin:password --request GET --config \ https://foreman.example.com/api/report_templates/158/export
Note that
158
is an example ID of the template to export.In this example, the exported template is redirected to
host_complete_list.erb
.
7.5. Importing Report Templates
You can import a report template into the body of a new template that you want to create. Note that using the web UI, you can only import templates individually. For bulk actions, use the Foreman API. For more information, see Importing Report Templates Using the Foreman API.
-
You must have exported templates from Foreman to import them to use in new templates. For more information see Exporting Report Templates.
-
In the Foreman web UI, navigate to Monitor > Report Templates, and in the upper right of the Report Templates window, click Create Template.
-
On the upper right of the Editor tab, click the folder icon, and select the
.erb
file that you want to import. -
Edit the template to suit your requirements, and click Submit.
For more information about customizing your new template, see Template Writing Reference.
7.6. Importing Report Templates Using the Foreman API
You can use the Foreman API to import report templates into Foreman. Importing report templates using the Foreman API automatically parses the report template metadata and assigns organizations and locations. For more information about using the Foreman API, see the API Guide.
-
Create a template using
.erb
syntax or export a template from another Foreman.For more information about writing templates, see Template Writing Reference.
For more information about exporting templates from Foreman, see Exporting Report Templates Using the Foreman API.
-
Use the following example to format the template that you want to import to a
.json
file:# cat Example_Template.json { "name": "Example Template Name", "template": " Enter ERB Code Here " }
Example JSON File with ERB Template:{ "name": "Hosts - complete list", "template": " <%# name: Hosts - complete list snippet: false template_inputs: - name: host required: false input_type: user advanced: false value_type: plain resource_type: Katello::ActivationKey model: ReportTemplate -%> <% load_hosts(search: input('host')).each_record do |host| -%> <% report_row( 'Server FQND': host.name ) -%> <% end -%> <%= report_render %> " }
-
Use the following request to import the template:
$ curl --insecure --user admin:redhat \ --data @Example_Template.json --header "Content-Type:application/json" \ --request POST --config https://foreman.example.com/api/report_templates/import
-
Use the following request to retrieve a list of report templates and validate that you can view the template in Foreman:
$ curl --insecure --user admin:redhat \ --request GET --config https://foreman.example.com/api/report_templates | json_reformat
7.7. Report Template Safe Mode
When you create report templates in Foreman, safe mode is enabled by default. Safe mode limits the macros and variables that you can use in the report template. Safe mode prevents rendering problems and enforces best practices in report templates. The list of supported macros and variables is available in the Foreman web UI.
To view the macros and variables that are available, in the Foreman web UI, navigate to Monitor > Report Templates and click Create Template. In the Create Template window, click the Help tab and expand Safe mode methods.
While safe mode is enabled, if you try to use a macro or variable that is not listed in Safe mode methods, the template editor displays an error message.
To view the status of safe mode in Foreman, in the Foreman web UI, navigate to Administer > Settings and click the Provisioning tab. Locate the Safemode rendering row to check the value.
8. Configuring Host Collections
This is for users of the Katello plug-in and hosts running RPM-based linux distributions. Hosts collections work via the Pulp back end.
A host collection is a group of multiple content hosts. This feature enables you to perform the same action on multiple hosts at once. These actions can include the installation, removal, and update of packages and errata, change of assigned life cycle environment, and change of Content View. You can create host collections to suit your requirements, and those of your company. For example, group hosts in host collections by function, department, or business unit.
8.1. Creating a Host Collection
The following procedure shows how to create host collections.
-
Click Hosts > Host Collections.
-
Click New Host Collection.
-
Add the Name of the host collection.
-
Clear Unlimited Content Hosts, and enter the desired maximum number of hosts in the Limit field.
-
Add the Description of the host collection.
-
Click Save.
-
To create a host collection, enter the following command:
# hammer host-collection create \ --organization "Your_Organization" \ --name hc_name
8.2. Cloning a Host Collection
The following procedure shows how to clone a host collection.
-
Click Hosts > Host Collections.
-
On the left hand panel, click the host collection you want to clone.
-
Click Copy Collection.
-
Specify a name for the cloned collection.
-
Click Create.
8.3. Removing a Host Collection
The following procedure shows how to remove a host collection.
-
Click Hosts > Host Collections.
-
Choose the host collection to be removed.
-
Click Remove. An alert box appears:
Are you sure you want to remove host collection Host Collection Name?
-
Click Remove.
8.4. Adding a Host to a Host Collection
The following procedure shows how to add hosts to host collections.
A host must be registered to Foreman to add it to a Host Collection.
Note that if you add a host to a host collection, the Foreman auditing system does not log the change.
-
Click Hosts > Host Collections.
-
Click the host collection where the host should be added.
-
On the Hosts tab, select the Add subtab.
-
Select the hosts to be added from the table and click Add Selected.
To add hosts to a host collection, enter the following command:
# hammer host-collection add-host \ --id hc_ID \ --host-ids host_ID1,host_ID2...
8.5. Removing a Host from a Host Collection
The following procedure shows how to remove hosts from host collections.
Note that if you remove a host from a host collection, the host collection record in the database is not modified so the Foreman auditing system does not log the change.
-
Click Hosts > Host Collections.
-
Choose the desired host collection.
-
On the Hosts tab, select the List/Remove subtab.
-
Select the hosts you want to remove from the host collection and click Remove Selected.
8.6. Adding Content to a Host Collection
These steps show how to add content to host collections in Foreman.
8.6.1. Adding Packages to a Host Collection
The following procedure shows how to add packages to host collections.
Prerequisites
-
The content to be added should be available in one of the existing repositories or added prior to this procedure.
-
Content should be promoted to the environment where the hosts are assigned.
-
Click Hosts > Host Collections.
-
Click the host collection where the package should be added.
-
On the Collection Actions tab, click Package Installation, Removal, and Update.
-
To update all packages, click the Update All Packages button to use the default method. Alternatively, select the drop-down icon to the right of the button to select a method to use. Selecting the via remote execution - customize first menu entry will take you to the Job invocation page where you can customize the action.
-
Select the Package or Package Group radio button as required.
-
In the field provided, specify the package or package group name. Then click:
-
Install - to install a new package using the default method. Alternatively, select the drop-down icon to the right of the button and select a method to use. Selecting the via remote execution - customize first menu entry will take you to the Job invocation page where you can customize the action.
-
Update - to update an existing package in the host collection using the default method. Alternatively, select the drop-down icon to the right of the button and select a method to use. Selecting the via remote execution - customize first menu entry will take you to the Job invocation page where you can customize the action.
-
8.6.2. Adding Errata to a Host Collection
The following procedure shows how to add errata to host collections.
Prerequisites
-
The errata to be added should be available in one of the existing repositories or added prior to this procedure.
-
Errata should be promoted to the environment where the hosts are assigned.
-
Click Hosts > Host Collections.
-
Select the host collection where the errata should be added.
-
On the Collection Actions tab, click Errata Installation.
-
Select the errata you want to add to the host collection and click the Install Selected button to use the default method. Alternatively, select the drop-down icon to the right of the button to select a method to use. Selecting the via remote execution - customize first menu entry will take you to the Job invocation page where you can customize the action.
8.7. Removing Content from a Host Collection
The following procedure shows how to remove packages from host collections.
-
Click Hosts > Host Collections.
-
Click the host collection where the package should be removed.
-
On the Collection Actions tab, click Package Installation, Removal, and Update.
-
Select the Package or Package Group radio button as required.
-
In the field provided, specify the package or package group name.
-
Click the Remove button to remove the package or package group using the default method. Alternatively, select the drop-down icon to the right of the button and select a method to use. Selecting the via remote execution - customize first menu entry will take you to the Job invocation page where you can customize the action.
8.8. Changing the Life Cycle Environment or Content View of a Host Collection
The following procedure shows how to change the assigned life cycle environment or Content View of host collections.
-
Click Hosts > Host Collection.
-
Selection the host collection where the life cycle environment or Content View should be changed.
-
On the Collection Actions tab, click Change assigned Life Cycle Environment or Content View.
-
Select the life cycle environment to be assigned to the host collection.
-
Select the required Content View from the list.
-
Click Assign.
NoteThe changes take effect in approximately 4 hours. To make the changes take effect immediately, on the host, enter the following command:
# subscription-manager refresh
You can use remote execution to run this command on multiple hosts at the same time.
9. Configuring and Setting up Remote Jobs
Use this section as a guide to configuring Foreman to execute jobs on remote hosts.
Any command that you want to apply to a remote host must be defined as a job template. After you have defined a job template you can execute it multiple times.
9.1. About Running Jobs on Hosts
You can run jobs on hosts remotely from Smart Proxies using shell scripts or Ansible tasks and playbooks. This is referred to as remote execution.
For custom Ansible roles that you create, or roles that you download, you must install the package containing the roles on the Smart Proxy base operating system. Before you can use Ansible roles, you must import the roles into Foreman from the Smart Proxy where they are installed.
Communication occurs through Smart Proxy server, which means that Foreman server does not require direct access to the target host, and can scale to manage many hosts. Remote execution uses the SSH service that must be enabled and running on the target host. Ensure that the remote execution Smart Proxy has access to port 22 on the target hosts.
Foreman uses ERB syntax job templates. For more information, see Template Writing Reference in the Managing Hosts guide.
Several job templates for shell scripts and Ansible are included by default. For more information, see Setting up Job Templates.
By default, Foreman server is configured to use the Katello Agent rather than remote execution. To change this setting, navigate to Administer > Settings, click Content, and change the Use remote execution by default setting.
Note
|
Any Smart Proxy server base operating system is a client of Foreman server’s internal Smart Proxy, and therefore this section applies to any type of host connected to Foreman server, including Smart Proxies. |
You can run jobs on multiple hosts at once, and you can use variables in your commands for more granular control over the jobs you run. You can use host facts and parameters to populate the variable values.
In addition, you can specify custom values for templates when you run the command.
For more information, see Executing a Remote Job.
9.2. Remote Execution Workflow
When you run a remote job on hosts, for every host, Foreman performs the following actions to find a remote execution Smart Proxy to use.
Foreman searches only for Smart Proxies that have the remote execution feature enabled.
-
Foreman finds the host’s interfaces that have the Remote execution check box selected.
-
Foreman finds the subnets of these interfaces.
-
Foreman finds remote execution Smart Proxies assigned to these subnets.
-
From this set of Smart Proxies, Foreman selects the Smart Proxy that has the least number of running jobs. By doing this, Foreman ensures that the jobs load is balanced between remote execution Smart Proxies.
-
If Foreman does not find a remote execution Smart Proxy at this stage, and if the Fallback to Any Smart Proxy setting is enabled, Foreman adds another set of Smart Proxies to select the remote execution Smart Proxy from. Foreman selects the most lightly loaded Smart Proxy from the following types of Smart Proxies that are assigned to the host:
-
DHCP, DNS and TFTP Smart Proxies assigned to the host’s subnets
-
DNS Smart Proxy assigned to the host’s domain
-
Realm Smart Proxy assigned to the host’s realm
-
Puppet Master Smart Proxy
-
Puppet CA Smart Proxy
-
OpenSCAP Smart Proxy
-
-
If Foreman does not find a remote execution Smart Proxy at this stage, and if the Enable Global Smart Proxy setting is enabled, Foreman selects the most lightly loaded remote execution Smart Proxy from the set of all Smart Proxies in the host’s organization and location to execute a remote job.
9.3. Permissions for Remote Execution
You can control which users can run which jobs within your infrastructure, including which hosts they can target. The remote execution feature provides two built-in roles:
-
Remote Execution Manager: This role allows access to all remote execution features and functionality.
-
Remote Execution User: This role only allows running jobs; it does not provide permission to modify job templates.
You can clone the Remote Execution User role and customize its filter for increased granularity.
If you adjust the filter with the view_job_templates
permission, the user can only see and trigger jobs based on matching job templates.
You can use the view_hosts
and view_smart_proxies
permissions to limit which hosts or Smart Proxies are visible to the role.
The execute_template_invocation
permission is a special permission that is checked immediately before execution of a job begins.
This permission defines which job template you can run on a particular host.
This allows for even more granularity when specifying permissions.
For more information on working with roles and permissions see Creating and Managing Roles in the Administering Foreman.
The following example shows filters for the execute_template_invocation
permission:
name = Reboot and host.name = staging.example.com name = Reboot and host.name ~ *.staging.example.com name = "Restart service" and host_group.name = webservers
The first line in this example permits the user to apply the Reboot template to one selected host. The second line defines a pool of hosts with names ending with .staging.example.com. The third line binds the template with a host group.
Note
|
Permissions assigned to users can change over time. If a user has already scheduled some jobs to run in the future, and the permissions have changed, this can result in execution failure because the permissions are checked immediately before job execution. |
9.4. Creating a Job Template
Use this procedure to create a job template. To use the CLI instead of the web UI, see the CLI procedure.
-
Navigate to Hosts > Job templates.
-
Click New Job Template.
-
Click the Template tab, and in the Name field, enter a unique name for your job template.
-
Select Default to make the template available for all organizations and locations.
-
Create the template directly in the template editor or upload it from a text file by clicking Import.
-
Optional: In the Audit Comment field, add information about the change.
-
Click the Job tab, and in the Job category field, enter your own category or select from the default categories listed in Default Job Template Categories.
-
Optional: In the Description Format field, enter a description template. For example,
Install package %{package_name}
. You can also use%{template_name}
and%{job_category}
in your template. -
From the Provider Type list, select SSH for shell scripts and Ansible for Ansible tasks or playbooks.
-
Optional: In the Timeout to kill field, enter a timeout value to terminate the job if it does not complete.
-
Optional: Click Add Input to define an input parameter. Parameters are requested when executing the job and do not have to be defined in the template. For examples, see the Help tab.
-
Optional: Click Foreign input set to include other templates in this job.
-
Optional: In the Effective user area, configure a user if the command cannot use the default
remote_execution_effective_user
setting. -
Optional: If this template is a snippet to be included in other templates, click the Type tab and select Snippet.
-
Click the Location tab and add the locations where you want to use the template.
-
Click the Organizations tab and add the organizations where you want to use the template.
-
Click Submit to save your changes.
You can extend and customize job templates by including other templates in the template syntax. For more information, see the appendices in the Managing Hosts guide.
-
To create a job template using a template-definition file, enter the following command:
# hammer job-template create \ --file "path_to_template_file" \ --name "template_name" \ --provider-type SSH \ --job-category "category_name"
9.5. Configuring the Fallback to Any Smart Proxy Remote Execution Setting in Foreman
You can enable the Fallback to Any Smart Proxy setting to configure Foreman to search for remote execution Smart Proxies from the list of Smart Proxies that are assigned to hosts. This can be useful if you need to run remote jobs on hosts that have no subnets configured or if the hosts' subnets are assigned to Smart Proxies that do not have the remote execution feature enabled.
If the Fallback to Any Smart Proxy setting is enabled, Foreman adds another set of Smart Proxies to select the remote execution Smart Proxy from. Foreman also selects the most lightly loaded Smart Proxy from the set of all Smart Proxies assigned to the host, such as the following:
-
DHCP, DNS and TFTP Smart Proxies assigned to the host’s subnets
-
DNS Smart Proxy assigned to the host’s domain
-
Realm Smart Proxy assigned to the host’s realm
-
Puppet Master Smart Proxy
-
Puppet CA Smart Proxy
-
OpenSCAP Smart Proxy
-
In the Foreman web UI, navigate to Administer > Settings.
-
Click RemoteExecution.
-
Configure the Fallback to Any Smart Proxy setting.
Enter the hammer settings set
command on Foreman to configure the Fallback to Any Smart Proxy setting.
For example, to set the value to true
, enter the following command:
# hammer settings set --name=remote_execution_fallback_proxy --value=true
9.6. Configuring the Global Smart Proxy Remote Execution Setting in Foreman
By default, Foreman searches for remote execution Smart Proxies in hosts' organizations and locations regardless of whether Smart Proxies are assigned to hosts' subnets or not. You can disable the Enable Global Smart Proxy setting if you want to limit the search to the Smart Proxies that are assigned to hosts' subnets.
If the Enable Global Smart Proxy setting is enabled, Foreman adds another set of Smart Proxies to select the remote execution Smart Proxy from. Foreman also selects the most lightly loaded remote execution Smart Proxy from the set of all Smart Proxies in the host’s organization and location to execute a remote job.
-
In the Foreman web UI, navigate to Administer > Settings.
-
Click RemoteExection.
-
Configure the Enable Global Smart Proxy setting.
-
Enter the
hammer settings set
command on Foreman to configure theEnable Global Smart Proxy
setting. For example, to set the value totrue
, enter the following command:# hammer settings set --name=remote_execution_global_proxy --value=true
9.7. Configuring Foreman to Use an Alternative Directory to Execute Remote Jobs on Hosts
By default, Foreman uses the /var/tmp
directory on the client system to execute the remote execution jobs.
If the client system has noexec
set for the /var/
volume or file system, you must configure Foreman to use an alternative directory because otherwise the remote execution job fails since the script cannot be run.
-
Create a new directory, for example new_place:
# mkdir /remote_working_dir
-
Copy the SELinux context from the default
var
directory:# chcon --reference=/var /remote_working_dir
-
Edit the
remote_working_dir
setting in the/etc/foreman-proxy/settings.d/remote_execution_ssh.yml
file to point to the required directory, for example::remote_working_dir: /remote_working_dir
9.8. Distributing SSH Keys for Remote Execution
To use SSH keys for authenticating remote execution connections, you must distribute the public SSH key from Smart Proxy to its attached hosts that you want to manage. Ensure that the SSH service is enabled and running on the hosts. Configure any network or host-based firewalls to enable access to port 22.
Use one of the following methods to distribute the public SSH key from Smart Proxy to target hosts:
-
Using the Foreman API to Obtain SSH Keys for Remote Execution.
-
Configuring a Kickstart Template to Distribute SSH Keys during Provisioning.
-
For new Foreman hosts, you can deploy SSH keys to Foreman hosts during registration using the global registration template. For more information, see Registering a Host to Foreman Using the Global Registration Template.
Foreman distributes SSH keys for the remote execution feature to the hosts provisioned from Foreman by default.
If the hosts are running on Amazon Web Services, enable password authentication. For more information, see https://aws.amazon.com/premiumsupport/knowledge-center/new-user-accounts-linux-instance.
9.9. Distributing SSH Keys for Remote Execution Manually
To distribute SSH keys manually, complete the following steps:
-
Enter the following command on Smart Proxy. Repeat for each target host you want to manage:
# ssh-copy-id -i ~foreman-proxy/.ssh/id_rsa_foreman_proxy.pub root@target.example.com
-
To confirm that the key was successfully copied to the target host, enter the following command on Smart Proxy:
# ssh -i ~foreman-proxy/.ssh/id_rsa_foreman_proxy root@target.example.com
9.10. Using the Foreman API to Obtain SSH Keys for Remote Execution
To use the Foreman API to download the public key from Smart Proxy, complete this procedure on each target host.
-
On the target host, create the
~/.ssh
directory to store the SSH key:# mkdir ~/.ssh
-
Download the SSH key from Smart Proxy:
# curl https://smartproxy.example.com:9090/ssh/pubkey >> ~/.ssh/authorized_keys
-
Configure permissions for the
~/.ssh
directory:# chmod 700 ~/.ssh
-
Configure permissions for the
authorized_keys
file:# chmod 600 ~/.ssh/authorized_keys
9.11. Configuring a Kickstart Template to Distribute SSH Keys during Provisioning
You can add a remote_execution_ssh_keys
snippet to your custom kickstart template to deploy SSH Keys to hosts during provisioning.
Kickstart templates that Foreman ships include this snippet by default.
Therefore, Foreman copies the SSH key for remote execution to the systems during provisioning.
-
To include the public key in newly-provisioned hosts, add the following snippet to the Kickstart template that you use:
<%= snippet 'remote_execution_ssh_keys' %>
9.12. Configuring a keytab for Kerberos Ticket Granting Tickets
Use this procedure to configure Foreman to use a keytab to obtain Kerberos ticket granting tickets. If you do not set up a keytab, you must manually retrieve tickets.
-
Find the ID of the
foreman-proxy
user:# id -u foreman-proxy
-
Modify the
umask
value so that new files have the permissions600
:# umask 077
-
Create the directory for the keytab:
# mkdir -p "/var/kerberos/krb5/user/USER_ID"
-
Create a keytab or copy an existing keytab to the directory:
# cp your_client.keytab /var/kerberos/krb5/user/USER_ID/client.keytab
-
Change the directory owner to the
foreman-proxy
user:# chown -R foreman-proxy:foreman-proxy "/var/kerberos/krb5/user/USER_ID"
-
Ensure that the keytab file is read-only:
# chmod -wx "/var/kerberos/krb5/user/USER_ID/client.keytab"
-
Restore the SELinux context:
# restorecon -RvF /var/kerberos/krb5
9.13. Configuring Kerberos Authentication for Remote Execution
You can use Kerberos authentication to establish an SSH connection for remote execution on Foreman hosts.
-
Enroll Foreman server on the Kerberos server
-
Enroll the Foreman target host on the Kerberos server
-
Configure and initialize a Kerberos user account for remote execution
-
Ensure that the foreman-proxy user on Foreman has a valid Kerberos ticket granting ticket
-
To install and enable Kerberos authentication for remote execution, enter the following command:
# foreman-installer --scenario foreman \ --foreman-proxy-plugin-remote-execution-ssh-ssh-kerberos-auth true
-
To edit the default user for remote execution, in the Foreman web UI, navigate to Administer > Settings and click the RemoteExecution tab. In the SSH User row, edit the second column and add the user name for the Kerberos account.
-
Navigate to remote_execution_effective_user and edit the second column to add the user name for the Kerberos account.
To confirm that Kerberos authentication is ready to use, run a remote job on the host.
9.14. Setting up Job Templates
Foreman provides default job templates that you can use for executing jobs. To view the list of job templates, navigate to Hosts > Job templates. If you want to use a template without making changes, proceed to Executing a Remote Job.
You can use default templates as a base for developing your own. Default job templates are locked for editing. Clone the template and edit the clone.
-
To clone a template, in the Actions column, select Clone.
-
Enter a unique name for the clone and click Submit to save the changes.
Job templates use the Embedded Ruby (ERB) syntax. For more information about writing templates, see the Template Writing Reference in the Managing Hosts guide.
To create an Ansible job template, use the following procedure and instead of ERB syntax, use YAML syntax.
Begin the template with ---
.
You can embed an Ansible playbook YAML file into the job template body.
You can also add ERB syntax to customize your YAML Ansible template.
You can also import Ansible playbooks in Foreman.
For more information, see Synchronizing Repository Templates in the Managing Hosts guide.
At run time, job templates can accept parameter variables that you define for a host. Note that only the parameters visible on the Parameters tab at the host’s edit page can be used as input parameters for job templates. If you do not want your Ansible job template to accept parameter variables at run time, in the Foreman web UI, navigate to Administer > Settings and click the Ansible tab. In the Top level Ansible variables row, change the Value parameter to No.
9.15. Executing a Remote Job
You can execute a job that is based on a job template against one or more hosts.
To use the CLI instead of the web UI, see the CLI procedure.
-
Navigate to Hosts > All Hosts and select the target hosts on which you want to execute a remote job. You can use the search field to filter the host list.
-
From the Select Action list, select Schedule Remote Job.
-
On the Job invocation page, define the main job settings:
-
Select the Job category and the Job template you want to use.
-
Optional: Select a stored search string in the Bookmark list to specify the target hosts.
-
Optional: Further limit the targeted hosts by entering a Search query. The Resolves to line displays the number of hosts affected by your query. Use the refresh button to recalculate the number after changing the query. The preview icon lists the targeted hosts.
-
The remaining settings depend on the selected job template. See Creating a Job Template for information on adding custom parameters to a template.
-
Optional: To configure advanced settings for the job, click Display advanced fields. Some of the advanced settings depend on the job template, the following settings are general:
-
Effective user defines the user for executing the job, by default it is the SSH user.
-
Concurrency level defines the maximum number of jobs executed at once, which can prevent overload of systems' resources in a case of executing the job on a large number of hosts.
-
Timeout to kill defines time interval in seconds after which the job should be killed, if it is not finished already. A task which could not be started during the defined interval, for example, if the previous task took too long to finish, is canceled.
-
Type of query defines when the search query is evaluated. This helps to keep the query up to date for scheduled tasks.
-
Execution ordering determines the order in which the job is executed on hosts: alphabetical or randomized.
Concurrency level and Timeout to kill settings enable you to tailor job execution to fit your infrastructure hardware and needs.
-
-
To run the job immediately, ensure that Schedule is set to Execute now. You can also define a one-time future job, or set up a recurring job. For recurring tasks, you can define start and end dates, number and frequency of runs. You can also use cron syntax to define repetition. For more information about cron, see the Automating System Tasks section of the Red Hat Enterprise Linux 7 System Administrator’s Guide.
-
Click Submit. This displays the Job Overview page, and when the job completes, also displays the status of the job.
-
Enter the following command on Foreman:
# hammer settings set --name=remote_execution_global_proxy --value=false
To execute a remote job with custom parameters, complete the following steps:
-
Find the ID of the job template you want to use:
# hammer job-template list
-
Show the template details to see parameters required by your template:
# hammer job-template info --id template_ID
-
Execute a remote job with custom parameters:
# hammer job-invocation create \ --job-template "template_name" \ --inputs key1="value",key2="value",... \ --search-query "query"
Replace query with the filter expression that defines hosts, for example
"name ~ rex01"
. For more information about executing remote commands with hammer, enterhammer job-template --help
andhammer job-invocation --help
.
9.16. Monitoring Jobs
You can monitor the progress of the job while it is running. This can help in any troubleshooting that may be required.
Ansible jobs run on batches of 100 hosts, so you cannot cancel a job running on a specific host. A job completes only after the Ansible playbook runs on all hosts in the batch.
-
Navigate to the Job page. This page is automatically displayed if you triggered the job with the
Execute now
setting. To monitor scheduled jobs, navigate to Monitor > Jobs and select the job run you wish to inspect. -
On the Job page, click the Hosts tab. This displays the list of hosts on which the job is running.
-
In the Host column, click the name of the host that you want to inspect. This displays the Detail of Commands page where you can monitor the job execution in real time.
-
Click Back to Job at any time to return to the Job Details page.
To monitor the progress of a job while it is running, complete the following steps:
-
Find the ID of a job:
# hammer job-invocation list
-
Monitor the job output:
# hammer job-invocation output \ --id job_ID \ --host host_name
-
Optional: to cancel a job, enter the following command:
# hammer job-invocation cancel \ --id job_ID
10. Host Management Without Goferd and Katello Agent
The goferd
service that is used by the Katello agent to manage packages on content hosts consumes large amount of resources.
To reduce memory and CPU load on content hosts, you can manage packages through remote execution.
Note that the Katello agent is deprecated and will be removed in a future Foreman version; therefore, using remote execution will be the only way to manage packages on hosts.
-
You have enabled the https://yum.theforeman.org/client/2.4/ repository on content hosts.
-
Install the
katello-host-tools
package on content hosts:# yum install katello-host-tools
-
Stop the goferd service on content hosts:
# systemctl stop goferd.service
-
Disable the goferd service on content hosts:
# systemctl disable goferd.service
-
Remove the Katello agent on content hosts:
WarningIf your host is installed on oVirt version 4.4 or lower, do not remove the katello-agent
package because the removed dependencies corrupt the host.# yum remove katello-agent
-
Distribute the SSH keys to the content hosts. For more information, see Distributing SSH Keys for Remote Execution.
-
In the Foreman web UI, navigate to Administer > Settings.
-
Select the Content tab.
-
Set the Use remote execution by default parameter to Yes.
The Foreman server now uses host management by remote execution instead of goferd.
The following applies if you are using the hammer
command to push errata.
The hammer
command is dependent on goferd to manage errata on content hosts.
As a workaround, use the Foreman remote execution feature to apply errata.
For example, enter the following command to perform a yum -y update
on host123.example.org:
# hammer job-invocation create \ --job-template "Run Command - SSH Default" \ --inputs command="yum -y update" \ --search-query "name ~ host123" Job invocation 24 created [.........................................] [100%] 1 task(s), 1 success, 0 fail
11. Synchronizing Template Repositories
In Foreman, you can synchronize repositories of job templates, provisioning templates, report templates, and partition table templates between Foreman server and a version control system or local directory. In this chapter, a Git repository is used for demonstration purposes.
This section details the workflow for:
-
installing and configuring the TemplateSync plug-in
-
performing exporting and importing tasks
11.1. Enabling the TemplateSync plug-in
-
To enable the plug-in on your Foreman server, enter the following command:
# foreman-installer --enable-foreman-plugin-templates
-
To verify that the plug-in is installed correctly, ensure Administer > Settings includes the TemplateSync menu.
11.2. Configuring the TemplateSync plug-in
In the Foreman web UI, navigate to Administer > Settings > TemplateSync to configure the plug-in. The following table explains the attributes behavior. Note that some attributes are used only for importing or exporting tasks.
Parameter | API parameter name | Meaning on importing | Meaning on exporting |
---|---|---|---|
Associate |
Accepted values: |
Associates templates with OS, Organization, and Location based on metadata. |
N/A |
Branch |
|
Specifies the default branch in Git repository to read from. |
Specifies the default branch in Git repository to write to. |
Dirname |
|
Specifies the subdirectory under the repository to read from. |
Specifies the subdirectory under the repository to write to. |
Filter |
|
Imports only templates with names that match this regular expression. |
Exports only templates with names that match this regular expression. |
Force import |
|
Imported templates overwrite locked templates with the same name. |
N/A |
Lock templates |
|
Do not overwrite existing templates when you import a new template with the same name, unless Force import is enabled. |
N/A |
Metadata export mode |
Accepted values: |
N/A |
Defines how metadata is handled when exporting:
|
Negate |
Accepted values: |
Imports templates ignoring the filter attribute. |
Exports templates ignoring the filter attribute. |
Prefix |
|
Adds specified string to the beginning of the template if the template name does not start with the prefix already. |
N/A |
Repo |
|
Defines the path to the repository to synchronize from. |
Defines the path to a repository to export to. |
Verbosity |
Accepted values: |
Enables writing verbose messages to the logs for this action. |
N/A |
11.3. Importing and Exporting Templates
You can import and export templates using the Foreman web UI, Hammer CLI, or Foreman API. Foreman API calls use the role-based access control system, which enables the tasks to be executed as any user. You can synchronize templates with a version control system, such as Git, or a local directory.
11.3.1. Importing Templates
You can import templates from a repository of your choice.
You can use different protocols to point to your repository, for example /tmp/dir
, git://example.com
, https://example.com
, and ssh://example.com
.
-
Each template must contain the location and organization that the template belongs to. This applies to all template types. Before you import a template, ensure that you add the following section to the template:
<%# kind: provision name: My Kickstart File oses: - RedHat 7 - RedHat 6 locations: - First Location - Second Location organizations: - Default Organization - Extra Organization %>
-
In the Foreman web UI, navigate to Hosts > Sync Templates.
-
Click Import.
-
Each field is populated with values configured in Administer > Settings > TemplateSync. Change the values as required for the templates you want to import. For more information about each field, see Configuring the TemplateSync plug-in.
-
Click Submit.
The Foreman web UI displays the status of the import. The status is not persistent; if you leave the status page, you cannot return to it.
-
To import a template from a repository, enter the following command:
$ hammer import-templates \ --prefix '[Custom Index] ' \ --filter '.*Template Name$' \ --repo https://github.com/examplerepo/exampledirectory \ --branch my_branch \ --organization 'Default Organization'
For better indexing and management of your templates, use
--prefix
to set a category for your templates. To select certain templates from a large repository, use--filter
to define the title of the templates that you want to import. For example--filter '.*Ansible Default$'
imports various Ansible Default templates.
11.3.2. Exporting Templates
You can export templates to a version control server, such as a Git repository.
-
In the Foreman web UI, navigate to Hosts > Sync Templates.
-
Click Export.
-
Each field is populated with values configured in Administer > Settings > TemplateSync. Change the values as required for the templates you want to export. For more information about each field, see Configuring the TemplateSync plug-in.
-
Click Submit.
The Foreman web UI displays the status of the export. The status is not persistent; if you leave the status page, you cannot return to it.
-
Clone a local copy of your Git repository:
$ git clone https://github.com/theforeman/community-templates /custom/templates
-
Change the owner of your local directory to the
foreman
user, and change the SELinux context with the following commands:# chown -R foreman:foreman /custom/templates # chcon -R -t httpd_sys_rw_content_t /custom/templates
-
To export the templates to your local repository, enter the following command:
hammer export-templates --organization 'Default Organization' --repo /custom/templates
11.3.3. Synchronizing Templates Using the Foreman API
-
Each template must contain the location and organization that the template belongs to. This applies to all template types. Before you import a template, ensure that you add the following section to the template:
<%# kind: provision name: My Kickstart File oses: - RedHat 7 - RedHat 6 locations: - First Location - Second Location organizations: - Default Organization - Extra Organization %>
-
Configure a version control system that uses SSH authorization, for example gitosis, gitolite, or git daemon.
-
Configure the TemplateSync plug-in settings on a TemplateSync tab.
-
Change the Branch setting to match the target branch on a Git server.
-
Change the Repo setting to match the Git repository. For example, for the repository located in
git@git.example.com/templates.git
set the setting intossh://git@git.example.com/templates.git
.
-
-
Accept Git SSH host key as the
foreman
user:# sudo -u foreman ssh git.example.com
You can see the
Permission denied, please try again.
message in the output, which is expected, because the SSH connection cannot succeed yet. -
Create an SSH key pair if you do not already have it. Do not specify a passphrase.
# sudo -u foreman ssh-keygen
-
Configure your version control server with the public key from your Foreman, which resides in
/usr/share/foreman/.ssh/id_rsa.pub
. -
Export templates from your Foreman server to the version control repository specified in the TemplateSync menu:
$ curl -H "Accept:application/json,version=2" \ -H "Content-Type:application/json" \ -u login:password \ -k https://_foreman.example.com/api/v2/templates/export \ -X POST {"message":"Success"}
-
Import templates to Foreman server after their content was changed:
$ curl -H "Accept:application/json,version=2" \ -H "Content-Type:application/json" \ -u login:password \ -k https://_foreman.example.com/api/v2/templates/import \ -X POST {“message”:”Success”}
Note that templates provided by Foreman are locked and you cannot import them by default. To overwrite this behavior, change the
Force import
setting in the TemplateSync menu toyes
or add theforce
parameter-d '{ "force": "true" }’
to the import command.
11.3.4. Synchronizing Templates with a Local Directory Using the Foreman API
Synchronizing templates with a local directory is useful if you have configured a version control repository in the local directory. That way, you can edit templates and track the history of edits in the directory. You can also synchronize changes to Foreman server after editing the templates.
-
Each template must contain the location and organization that the template belongs to. This applies to all template types. Before you import a template, ensure that you add the following section to the template:
<%# kind: provision name: My Kickstart File oses: - RedHat 7 - RedHat 6 locations: - First Location - Second Location organizations: - Default Organization - Extra Organization %>
-
Create the directory where templates are stored and apply appropriate permissions and SELinux context:
# mkdir -p /usr/share/templates_dir/ # chown foreman /usr/share/templates_dir/ # chcon -t httpd_sys_rw_content_t /usr/share/templates_dir/ -R
-
Change the Repo setting on the TemplateSync tab to match the export directory
/usr/share/templates_dir/
. -
Export templates from your Foreman server to a local directory:
$ curl -H "Accept:application/json,version=2" \ -H "Content-Type:application/json" \ -u login:password \ -k https://_foreman.example.com/api/v2/templates/export \ -X POST \ {"message":"Success"}
-
Import templates to Foreman server after their content was changed:
$ curl -H "Accept:application/json,version=2" \ -H "Content-Type:application/json" \ -u login:password \ -k https://_foreman.example.com/api/v2/templates/import \ -X POST {“message”:”Success”}
Note that templates provided by Foreman are locked and you cannot import them by default. To overwrite this behavior, change the
Force import
setting in the TemplateSync menu toyes
or add theforce
parameter-d '{ "force": "true" }’
to the import command.
Note
|
You can override default API settings by specifying them in the request with the $ curl -H "Accept:application/json,version=2" \ -H "Content-Type:application/json" \ -u login:password \ -k https://foreman.example.com/api/v2/templates/export \ -X POST \ -d "{\"repo\":\"git.example.com/templates\"}" |
11.4. Advanced Git Configuration
You can perform additional Git configuration for the TemplateSync plug-in using the command line or editing the .gitconfig
file.
If you are using a self-signed certificate authentication on your Git server, validate the certificate with the git config http.sslCAPath
command.
For example, the following command verifies a self-signed certificate stored in /cert/cert.pem
:
# sudo -u foreman git config --global http.sslCAPath cert/cert.pem
For a complete list of advanced options, see the git-config
manual page.
11.5. Uninstalling the plug-in
To avoid errors after removing the foreman_templates plugin:
-
Disable the plug-in using the Foreman installer:
# foreman-installer --no-enable-foreman-plugin-templates
-
Clean custom data of the plug-in. The command does not affect any templates that you created.
# foreman-rake templates:cleanup
-
Uninstall the plug-in:
# yum remove foreman-plugin-templates
Appendix A: Template Writing Reference
Embedded Ruby (ERB) is a tool for generating text files based on templates that combine plain text with Ruby code. Foreman uses ERB syntax in the following cases:
- Provisioning templates
-
For more information, see Creating Provisioning Templates in the Provisioning Guide.
- Remote execution job templates
-
For more information, see Configuring and Setting up Remote Jobs.
- Report templates
-
For more information, see Using Report Templates to Monitor Hosts.
- Templates for partition tables
-
For more information, see Creating Partition Tables in the Provisioning Guide.
- Smart Variables
-
For more information, see Configuring Smart Variables in the Puppet Guide.
- Smart Class Parameters
-
For more information, see Configuring Smart Class Parameters in the Puppet Guide.
This section provides an overview of Foreman-specific macros and variables that can be used in ERB templates along with some usage examples. Note that the default templates provided by Foreman (Hosts > Provisioning templates, Hosts > Job templates, Monitor > Report Templates ) also provide a good source of ERB syntax examples.
When provisioning a host or running a remote job, the code in the ERB is executed and the variables are replaced with the host specific values. This process is referred to as rendering. Foreman server has the safemode rendering option enabled by default, which prevents any harmful code being executed from templates.
Accessing the Template Writing Reference in the Foreman web UI
You can access the template writing reference document in the Foreman web UI.
-
Log in to the Foreman web UI.
-
Navigate to Administer > About.
-
Click the Templates DSL link in the Support section.
Writing ERB Templates
The following tags are the most important and commonly used in ERB templates:
All Ruby code is enclosed within <% %>
in an ERB template.
The code is executed when the template is rendered.
It can contain Ruby control flow structures as well as Foreman-specific macros and variables.
For example:
<% if @host.operatingsystem.family == "Redhat" && @host.operatingsystem.major.to_i > 6 -%> systemctl <%= input("action") %> <%= input("service") %> <% else -%> service <%= input("service") %> <%= input("action") %> <% end -%>
Note that this template silently performs an action with a service and returns nothing at the output.
This provides the same functionality as <% %>
but when the template is executed, the code output is inserted into the template.
This is useful for variable substitution, for example:
Example input:
echo <%= @host.name %>
Example rendering:
host.example.com
Example input:
<% server_name = @host.fqdn %> <%= server_name %>
Example rendering:
host.example.com
Note that if you enter an incorrect variable, no output is returned. However, if you try to call a method on an incorrect variable, the following error message returns:
Example input:
<%= @example_incorrect_variable.fqdn -%>
Example rendering:
undefined method `fqdn' for nil:NilClass
By default, a newline character is inserted after a Ruby block if it is closed at the end of a line:
Example input:
<%= "line1" %> <%= "line2" %>
Example rendering:
line1 line2
To change the default behavior, modify the enclosing mark with -%>
:
Example input:
<%= "line1" -%> <%= "line2" %>
Example rendering:
line1line2
This is used to reduce the number of lines, where Ruby syntax permits, in rendered templates. White spaces in ERB tags are ignored.
An example of how this would be used in a report template to remove unnecessary newlines between a FQDN and IP address:
Example input:
<%= @host.fqdn -%> <%= @host.ip -%>
Example rendering:
host.example.com10.10.181.216
Encloses a comment that is ignored during template rendering:
Example input:
<%# A comment %>
This generates no output.
Because of the varying lengths of the ERB tags, indenting the ERB syntax might seem messy. ERB syntax ignore white space. One method of handling the indentation is to declare the ERB tag at the beginning of each new line and then use white space within the ERB tag to outline the relationships within the syntax, for example:
<%- load_hosts.each do |host| -%> <%- if host.build? %> <%= host.name %> build is in progress <%- end %> <%- end %>
Troubleshooting ERB Templates
The Foreman web UI provides two ways to verify the template rendering for a specific host:
-
Directly in the template editor – when editing a template (under Hosts > Partition tables, Hosts > Provisioning templates, or Hosts > Job templates), on the Template tab click Preview and select a host from the list. The template then renders in the text field using the selected host’s parameters. Preview failures can help to identify issues in your template.
-
At the host’s details page – select a host at Hosts > All hosts and click the Templates tab to list templates associated with the host. Select Review from the list next to the selected template to view it’s rendered version.
Generic Foreman-Specific Macros
This section lists Foreman-specific macros for ERB templates.
You can use the macros listed in the following table across all kinds of templates.
Name | Description |
---|---|
indent(n) |
Indents the block of code by n spaces, useful when using a snippet template that is not indented. |
foreman_url(kind) |
Returns the full URL to host-rendered templates of the given kind. For example, templates of the "provision" type usually reside at http://HOST/unattended/provision. |
snippet(name) |
Renders the specified snippet template. Useful for nesting provisioning templates. |
snippets(file) |
Renders the specified snippet found in the Foreman database, attempts to load it from the unattended/snippets/ directory if it is not found in the database. |
snippet_if_exists(name) |
Renders the specified snippet, skips if no snippet with the specified name is found. |
Templates Macros
If you want to write custom templates, you can use some of the following macros.
Depending on the template type, some of the following macros have different requirements.
For more information about the available macros for report templates, in the Foreman web UI, navigate to Monitor > Report Templates, and click Create Template. In the Create Template window, click the Help tab.
For more information about the available macros for job templates, in the Foreman web UI, navigate to Hosts > Job Templates, and click the New Job Template. In the New Job Template window, click the Help tab.
- input
-
Using the
input
macro, you can customize the input data that the template can work with. You can define the input name, type, and the options that are available for users. For report templates, you can only use user inputs. When you define a new input and save the template, you can then reference the input in the ERB syntax of the template body.<%= input('cpus') %>
This loads the value from user input
cpus
. - load_hosts
-
Using the
load_hosts
macro, you can generate a complete list of hosts.<%- load_hosts().each_record do |host| -%> <%= host.name %>
Use the
load_hosts
macro with theeach_record
macro to load records in batches of 1000 to reduce memory consumption.If you want to filter the list of hosts for the report, you can add the option
search: input(‘Example_Host’)
:<% load_hosts(search: input('Example_Host')).each_record do |host| -%> <%= host.name %> <% end -%>
In this example, you first create an input that you then use to refine the search criteria that the
load_hosts
macro retrieves. - report_row
-
Using the
report_row
macro, you can create a formatted report for ease of analysis. Thereport_row
macro requires thereport_render
macro to generate the output.Example input:<%- load_hosts(search: input('Example_Host')).each_record do |host| -%> <%- report_row( 'Server FQDN': host.name ) -%> <%- end -%> <%= report_render -%>
Example rendering:Server FQDN host1.example.com host2.example.com host3.example.com host4.example.com host5.example.com host6.example.com
You can add extra columns to the report by adding another header. The following example adds IP addresses to the report:
Example input:<%- load_hosts(search: input('host')).each_record do |host| -%> <%- report_row( 'Server FQDN': host.name, 'IP': host.ip ) -%> <%- end -%> <%= report_render -%>
Example rendering:Server FQDN,IP host1.example.com,10.8.30.228 host2.example.com,10.8.30.227 host3.example.com,10.8.30.226 host4.example.com,10.8.30.225 host5.example.com,10.8.30.224 host6.example.com,10.8.30.223
- report_render
-
This macro is available only for report templates.
Using the
report_render
macro, you create the output for the report. During the template rendering process, you can select the format that you want for the report. YAML, JSON, HTML, and CSV formats are supported.<%= report_render -%>
- render_template()
-
This macro is available only for job templates.
Using this macro, you can render a specific template. You can also enable and define arguments that you want to pass to the template.
Host-Specific Variables
The following variables enable using host data within templates.
Note that job templates accept only @host
variables.
Name | Description |
---|---|
@host.architecture |
The architecture of the host. |
@host.bond_interfaces |
Returns an array of all bonded interfaces. See Parsing Arrays. |
@host.capabilities |
The method of system provisioning, can be either build (for example kickstart) or image. |
@host.certname |
The SSL certificate name of the host. |
@host.diskLayout |
The disk layout of the host. Can be inherited from the operating system. |
@host.domain |
The domain of the host. |
@host.environment |
The Puppet environment of the host. |
@host.facts |
Returns a Ruby hash of facts from Facter. For example to access the 'ipaddress' fact from the output, specify @host.facts['ipaddress']. |
@host.grub_pass |
Returns the host’s GRUB password. |
@host.hostgroup |
The host group of the host. |
host_enc['parameters'] |
Returns a Ruby hash containing information on host parameters. For example, use host_enc['parameters']['lifecycle_environment'] to get the life cycle environment of a host. |
@host.image_build? |
Returns |
@host.interfaces |
Contains an array of all available host interfaces including the primary interface. See Parsing Arrays. |
@host.interfaces_with_identifier('IDs') |
Returns array of interfaces with given identifier. You can pass an array of multiple identifiers as an input, for example @host.interfaces_with_identifier(['eth0', 'eth1']). See Parsing Arrays. |
@host.ip |
The IP address of the host. |
@host.location |
The location of the host. |
@host.mac |
The MAC address of the host. |
@host.managed_interfaces |
Returns an array of managed interfaces (excluding BMC and bonded interfaces). See Parsing Arrays. |
@host.medium |
The assigned operating system installation medium. |
@host.name |
The full name of the host. |
@host.operatingsystem.family |
The operating system family. |
@host.operatingsystem.major |
The major version number of the assigned operating system. |
@host.operatingsystem.minor |
The minor version number of the assigned operating system. |
@host.operatingsystem.name |
The assigned operating system name. |
@host.operatingsystem.boot_files_uri(medium_provider) |
Full path to the kernel and initrd, returns an array. |
@host.os.medium_uri(@host) |
The URI used for provisioning (path configured in installation media). |
host_param('parameter_name') |
Returns the value of the specified host parameter. |
host_param_false?('parameter_name') |
Returns |
host_param_true?('parameter_name') |
Returns |
@host.primary_interface |
Returns the primary interface of the host. |
@host.provider |
The compute resource provider. |
@host.provision_interface |
Returns the provisioning interface of the host. Returns an interface object. |
@host.ptable |
The partition table name. |
@host.puppet_ca_server |
The Puppet CA server the host must use. |
@host.puppetmaster |
The Puppet master the host must use. |
@host.pxe_build? |
Returns |
@host.shortname |
The short name of the host. |
@host.sp_ip |
The IP address of the BMC interface. |
@host.sp_mac |
The MAC address of the BMC interface. |
@host.sp_name |
The name of the BMC interface. |
@host.sp_subnet |
The subnet of the BMC network. |
@host.subnet.dhcp |
Returns |
@host.subnet.dns_primary |
The primary DNS server of the host. |
@host.subnet.dns_secondary |
The secondary DNS server of the host. |
@host.subnet.gateway |
The gateway of the host. |
@host.subnet.mask |
The subnet mask of the host. |
@host.url_for_boot(:initrd) |
Full path to the initrd image associated with this host. Not recommended, as it does not interpolate variables. |
@host.url_for_boot(:kernel) |
Full path to the kernel associated with this host. Not recommended, as it does not interpolate variables, prefer boot_files_uri. |
@provisioning_type |
Equals to 'host' or 'hostgroup' depending on type of provisioning. |
@static |
Returns |
@template_name |
Name of the template being rendered. |
grub_pass |
Returns the GRUB password wrapped in md5pass argument, that is --md5pass=#{@host.grub_pass}. |
ks_console |
Returns a string assembled using the port and the baud rate of the host which can be added to a kernel line. For example console=ttyS1,9600. |
root_pass |
Returns the root password configured for the system. |
The majority of common Ruby methods can be applied on host-specific variables. For example, to extract the last segment of the host’s IP address, you can use:
<% @host.ip.split('.').last %>
Kickstart-Specific Variables
The following variables are designed to be used within kickstart provisioning templates.
Name | Description |
---|---|
@arch |
The host architecture name, same as @host.architecture.name. |
@dynamic |
Returns |
@epel |
A command which will automatically install the correct version of the epel-release rpm. Use in a %post script. |
@mediapath |
The full kickstart line to provide the URL command. |
@osver |
The operating system major version number, same as @host.operatingsystem.major. |
Conditional Statements
In your templates, you might perform different actions depending on which value exists. To achieve this, you can use conditional statements in your ERB syntax.
In the following example, the ERB syntax searches for a specific host name and returns an output depending on the value it finds:
Example input:
<% load_hosts().each_record do |host| -%> <% if @host.name == "host1.example.com" -%> <% result="positive" -%> <% else -%> <% result="negative" -%> <% end -%> <%= result -%>
Example rendering:
host1.example.com positive
Parsing Arrays
While writing or modifying templates, you might encounter variables that return arrays.
For example, host variables related to network interfaces, such as @host.interfaces
or @host.bond_interfaces
, return interface data grouped in an array.
To extract a parameter value of a specific interface, use Ruby methods to parse the array.
The following procedure is an example that you can use to find the relevant methods to parse arrays in your template. In this example, a report template is used, but the steps are applicable to other templates.
-
To retrieve the NIC of a content host, in this example, using the
@host.interfaces
variable returns class values that you can then use to find methods to parse the array.Example input:<%= @host.interfaces -%>
Example rendering:<Nic::Base::ActiveRecord_Associations_CollectionProxy:0x00007f734036fbe0>
-
In the Create Template window, click the Help tab and search for the
ActiveRecord_Associations_CollectionProxy
andNic::Base
classes. -
For
ActiveRecord_Associations_CollectionProxy
, in the Allowed methods or members column, you can view the following methods to parse the array:[] each find_in_batches first map size to_a
-
For
Nic::Base
, in the Allowed methods or members column, you can view the following method to parse the array:alias? attached_devices attached_devices_identifiers attached_to bond_options children_mac_addresses domain fqdn identifier inheriting_mac ip ip6 link mac managed? mode mtu nic_delay physical? primary provision shortname subnet subnet6 tag virtual? vlanid
-
To iterate through an interface array, add the relevant methods to the ERB syntax:
Example input:<% load_hosts().each_record do |host| -%> <% host.interfaces.each do |iface| -%> iface.alias?: <%= iface.alias? %> iface.attached_to: <%= iface.attached_to %> iface.bond_options: <%= iface.bond_options %> iface.children_mac_addresses: <%= iface.children_mac_addresses %> iface.domain: <%= iface.domain %> iface.fqdn: <%= iface.fqdn %> iface.identifier: <%= iface.identifier %> iface.inheriting_mac: <%= iface.inheriting_mac %> iface.ip: <%= iface.ip %> iface.ip6: <%= iface.ip6 %> iface.link: <%= iface.link %> iface.mac: <%= iface.mac %> iface.managed?: <%= iface.managed? %> iface.mode: <%= iface.mode %> iface.mtu: <%= iface.mtu %> iface.physical?: <%= iface.physical? %> iface.primary: <%= iface.primary %> iface.provision: <%= iface.provision %> iface.shortname: <%= iface.shortname %> iface.subnet: <%= iface.subnet %> iface.subnet6: <%= iface.subnet6 %> iface.tag: <%= iface.tag %> iface.virtual?: <%= iface.virtual? %> iface.vlanid: <%= iface.vlanid %> <%- end -%>
Example rendering:host1.example.com iface.alias?: false iface.attached_to: iface.bond_options: iface.children_mac_addresses: [] iface.domain: iface.fqdn: host1.example.com iface.identifier: ens192 iface.inheriting_mac: 00:50:56:8d:4c:cf iface.ip: 10.10.181.13 iface.ip6: iface.link: true iface.mac: 00:50:56:8d:4c:cf iface.managed?: true iface.mode: balance-rr iface.mtu: iface.physical?: true iface.primary: true iface.provision: true iface.shortname: host1.example.com iface.subnet: iface.subnet6: iface.tag: iface.virtual?: false iface.vlanid:
Example Template Snippets
The following example checks if the host has the Puppet and Puppetlabs repositories enabled:
<% pm_set = @host.puppetmaster.empty? ? false : true puppet_enabled = pm_set || host_param_true?('force-puppet') puppetlabs_enabled = host_param_true?('enable-puppetlabs-repo') %>
The following example shows how to capture the minor and major version of the host’s operating system, which can be used for package related decisions:
<% os_major = @host.operatingsystem.major.to_i os_minor = @host.operatingsystem.minor.to_i %> <% if ((os_minor < 2) && (os_major < 14)) -%> ... <% end -%>
The following example imports the subscription_manager_registration snippet to the template and indents it by four spaces:
<%= indent 4 do snippet 'subscription_manager_registration' end %>
The following example imports the kickstart_networking_setup
snippet if the host’s subnet has the DHCP boot mode enabled:
<% subnet = @host.subnet %> <% if subnet.respond_to?(:dhcp_boot_mode?) -%> <%= snippet 'kickstart_networking_setup' %> <% end -%>
You can use the host.facts
variable to parse values from a host’s facts and custom facts.
In this example luks_stat
is a custom fact that you can parse in the same manner as dmi::system::serial_number
, which is a host fact:
'Serial': host.facts['dmi::system::serial_number'], 'Encrypted': host.facts['luks_stat'],
In this example, you can customize the Applicable Errata report template to parse for custom information about the kernel version of each host:
<%- report_row( 'Host': host.name, 'Operating System': host.operatingsystem, 'Kernel': host.facts['uname::release'], 'Environment': host.lifecycle_environment, 'Erratum': erratum.errata_id, 'Type': erratum.errata_type, 'Published': erratum.issued, 'Applicable since': erratum.created_at, 'Severity': erratum.severity, 'Packages': erratum.package_names, 'CVEs': erratum.cves, 'Reboot suggested': erratum.reboot_suggested, ) -%>
Appendix B: Job Template Examples and Extensions
Use this section as a reference to help modify, customize, and extend your job templates to suit your requirements.
Customizing Job Templates
When creating a job template, you can include an existing template in the template editor field. This way you can combine templates, or create more specific templates from the general ones.
The following template combines default templates to install and start the httpd service on Red Hat Enterprise Linux systems:
<%= render_template 'Package Action - SSH Default', :action => 'install', :package => 'httpd' %>
<%= render_template 'Service Action - SSH Default', :action => 'start', :service_name => 'httpd' %>
The above template specifies parameter values for the rendered template directly. It is also possible to use the input() method to allow users to define input for the rendered template on job execution. For example, you can use the following syntax:
<%= render_template 'Package Action - SSH Default', :action => 'install', :package => input("package") %>
With the above template, you have to import the parameter definition from the rendered template. To do so, navigate to the Jobs tab, click Add Foreign Input Set, and select the rendered template from the Target template list. You can import all parameters or specify a comma separated list.
Default Job Template Categories
Job template category | Description |
---|---|
Packages |
Templates for performing package related actions. Install, update, and remove actions are included by default. |
Puppet |
Templates for executing Puppet runs on target hosts. |
Power |
Templates for performing power related actions. Restart and shutdown actions are included by default. |
Commands |
Templates for executing custom commands on remote hosts. |
Services |
Templates for performing service related actions. Start, stop, restart, and status actions are included by default. |
Katello |
Templates for performing content related actions. These templates are used mainly from different parts of the Foreman web UI (for example bulk actions UI for content hosts), but can be used separately to perform operations such as errata installation. |
Example restorecon Template
This example shows how to create a template called Run Command - restorecon that restores the default SELinux context for all files in the selected directory on target hosts.
-
Navigate to Hosts > Job templates. Click New Job Template.
-
Enter Run Command - restorecon in the Name field. Select Default to make the template available to all organizations. Add the following text to the template editor:
restorecon -RvF <%= input("directory") %>
The
<%= input("directory") %>
string is replaced by a user-defined directory during job invocation. -
On the Job tab, set Job category to
Commands
. -
Click Add Input to allow job customization. Enter
directory
to the Name field. The input name must match the value specified in the template editor. -
Click Required so that the command cannot be executed without the user specified parameter.
-
Select User input from the Input type list. Enter a description to be shown during job invocation, for example
Target directory for restorecon
. -
Click Submit.
See Executing a restorecon Template on Multiple Hosts for information on how to execute a job based on this template.
Rendering a restorecon Template
This example shows how to create a template derived from the Run command - restorecon template created in Example restorecon Template. This template does not require user input on job execution, it will restore the SELinux context in all files under the /home/ directory on target hosts.
Create a new template as described in Setting up Job Templates, and specify the following string in the template editor:
<%= render_template("Run Command - restorecon", :directory => "/home") %>
Executing a restorecon Template on Multiple Hosts
This example shows how to run a job based on the template created in Example restorecon Template on multiple hosts. The job restores the SELinux context in all files under the /home/ directory.
-
Navigate to Hosts > All hosts and select target hosts. Select Schedule Remote Job from the Select Action list.
-
In the Job invocation page, select the
Commands
job category and theRun Command - restorecon
job template. -
Type
/home
in the directory field. -
Set Schedule to
Execute now
. -
Click Submit. You are taken to the Job invocation page where you can monitor the status of job execution.
Including Power Actions in Templates
This example shows how to set up a job template for performing power actions, such as reboot. This procedure prevents Foreman from interpreting the disconnect exception upon reboot as an error, and consequently, remote execution of the job works correctly.
Create a new template as described in Setting up Job Templates, and specify the following string in the template editor:
<%= render_template("Power Action - SSH Default", :action => "restart") %>