Installing Foreman 2.4 server on Debian

1. Preparing your Environment for Installation

Before you install Foreman, ensure that your environment meets the following requirements.

1.1. System Requirements

The following requirements apply to the networked base operating system:

x86_64 architecture
4-core 2.0 GHz CPU at a minimum
A minimum of 4 GB RAM is required for Foreman server to function. Foreman running with less RAM than the minimum value might not operate correctly.
Administrative user (root) access
A system umask of 0022
Full forward and reverse DNS resolution using a fully-qualified domain name

Before you install Foreman server, ensure that your environment meets the requirements for installation.

Foreman server must be installed on a freshly provisioned system that serves no other function except to run Foreman server. The freshly provisioned system must not have the following users provided by external identity providers to avoid conflicts with the local users that Foreman server creates:

apache
foreman
foreman-proxy
postgres
puppet
puppetserver

The following table details storage requirements for specific directories. These values are based on expected use case scenarios and can vary according to individual environments.

1.2.1. Debian 10 (Buster)

Table 1. Storage Requirements for a Foreman server Installation
Directory	Installation Size	Runtime Size
/var/log/	10 MB	10 GB
/var/lib/postgresql/11	100 MB	20 GB
/usr	3 GB	Not Applicable
/opt/puppetlabs	500 MB	Not Applicable

1.2.2. Ubuntu 18.04 (Bionic)

Table 2. Storage Requirements for a Foreman server Installation
Directory	Installation Size	Runtime Size
/var/log/	10 MB	10 GB
/var/lib/postgresql/11	100 MB	20 GB
/usr	3 GB	Not Applicable
/opt/puppetlabs	500 MB	Not Applicable

1.3. Supported Operating Systems

You can install the operating system from a disc, local ISO image, or kickstart.

The following operating systems are supported by the installer, have packages, and are tested for deploying Foreman:

Table 3. Operating Systems supported by foreman-installer
Operating System	Architecture	Notes
Ubuntu 18.04 (Bionic)	amd64
Debian 10 (Buster)	amd64

Before you install Foreman, apply all operating system updates if possible.

Install Foreman server on a freshly provisioned system.

1.4. Supported Browsers

The recommended requirements are as follows for major browsers:

Google Chrome 54 or higher
Microsoft Edge
Microsoft Internet Explorer 10 or higher
Mozilla Firefox 49 or higher

Other browsers may work unpredictably.

The Foreman web UI and command-line interface support English, Portuguese, Simplified Chinese Traditional Chinese, Korean, Japanese, Italian, Spanish, Russian, French, and German.

1.5. Ports and Firewalls Requirements

For the components of Foreman architecture to communicate, ensure that the required network ports are open and free on the base operating system. You must also ensure that the required network ports are open on any network-based firewalls.

Use this information to configure any network-based firewalls. Note that some cloud solutions must be specifically configured to allow communications between machines because they isolate machines similarly to network-based firewalls. If you use an application-based firewall, ensure that the application-based firewall permits all applications that are listed in the tables and known to your firewall. If possible, disable the application checking and allow open port communication based on the protocol.

Integrated Smart Proxy

Foreman server has an integrated Smart Proxy and any host that is directly connected to Foreman server is a Client of Foreman in the context of this section. This includes the base operating system on which Smart Proxy server is running.

Clients of Smart Proxy

Hosts which are clients of Smart Proxies, other than Foreman’s integrated Smart Proxy, do not need access to Foreman server.

Required ports can change based on your configuration.

The following tables indicate the destination port and the direction of network traffic:

Table 4. Ports for Browser-based User Interface Access to Foreman
Port	Protocol	Service	Required For
443	TCP	HTTPS	Browser-based UI access to Foreman
80	TCP	HTTP	Redirection to HTTPS for web UI access to Foreman (Optional)

Table 5. Ports for Client to Foreman Communication
Port	Protocol	Service	Required For
80	TCP	HTTP	Anaconda, yum, for obtaining Katello certificates, templates, and for downloading iPXE firmware
443	TCP	HTTPS	Subscription Management Services, yum, Telemetry Services and client connections
8000	TCP	HTTP	Anaconda to download kickstart templates to hosts, and for downloading iPXE firmware
8140	TCP	HTTPS	Puppet agent to Puppet master connections
9090	TCP	HTTPS	Sending SCAP reports to the integrated Smart Proxy, for the discovery image during provisioning, and for communicating with Foreman server to copy the SSH keys for Remote Execution (Rex) configuration
7	TCP and UDP	ICMP	External DHCP on a Client to Foreman network, ICMP ECHO to verify IP address is free (Optional)
53	TCP and UDP	DNS	Client DNS queries to a Foreman’s integrated Smart Proxy DNS service (Optional)
67	UDP	DHCP	Client to Foreman’s integrated Smart Proxy broadcasts, DHCP broadcasts for Client provisioning from a Foreman’s integrated Smart Proxy (Optional)
69	UDP	TFTP	Clients downloading PXE boot image files from a Foremans' integrated Smart Proxy for provisioning (Optional)

Any managed host that is directly connected to Foreman server is a client in this context because it is a client of the integrated Smart Proxy. This includes the base operating system on which a Smart Proxy server is running.

Table 6. Ports for Foreman to Smart Proxy Communication
Port	Protocol	Service	Required for
443	TCP	HTTPS	Connections to the Pulp server in the Smart Proxy
9090	TCP	HTTPS	Connections to the proxy in the Smart Proxy
80	TCP	HTTP	Downloading a bootdisk (Optional)

Table 7. Optional Network Ports
Port	Protocol	Service	Required For
22	TCP	SSH	Foreman and Smart Proxy originated communications, for Remote Execution (Rex) and Ansible.
443	TCP	HTTPS	Foreman originated communications, for vCenter compute resource.
5000	TCP	HTTP	Foreman originated communications, for compute resources in OpenStack or for running containers.
22, 16514	TCP	SSH, SSL/TLS	Foreman originated communications, for compute resources in libvirt.
389, 636	TCP	LDAP, LDAPS	Foreman originated communications, for LDAP and secured LDAP authentication sources.
5900 to 5930	TCP	SSL/TLS	Foreman originated communications, for NoVNC console in web UI to hypervisors.

1.6. Enabling Connections from a Client to Foreman server

Smart Proxies and Content Hosts that are clients of a Foreman server’s internal Smart Proxy require access through Foreman’s host-based firewall and any network-based firewalls.

Use this procedure to configure the host-based firewall on the Red Hat Enterprise Linux 7 system that Foreman is installed on, to enable incoming connections from Clients, and to make the configuration persistent across system reboots. For more information on the ports used, see Ports and Firewalls Requirements.

If you do not use firewall-cmd to configure the Linux firewall, implement using the command of your choice.

Procedure

To open the ports for client to Foreman communication, enter the following command on the base operating system that you want to install Foreman on:

# firewall-cmd \
--add-port="80/tcp" --add-port="443/tcp" \
--add-port="5647/tcp" --add-port="8000/tcp" \
--add-port="8140/tcp" --add-port="9090/tcp" \
--add-port="53/udp" --add-port="53/tcp" \
--add-port="67/udp" --add-port="69/udp" \
--add-port="5000/tcp"

Make the changes persistent:
```
# firewall-cmd --runtime-to-permanent
```

1.7. Verifying Firewall Settings

Use this procedure to verify your changes to the firewall settings.

If you do not use firewall-cmd to configure the Linux firewall, implement using the command of your choice.

Procedure

Enter the following command:
```
# firewall-cmd --list-all
```

1.8. Verifying DNS resolution

Verify the full forward and reverse DNS resolution using a fully-qualified domain name to prevent issues while installing Foreman.

Procedure

Ensure that the host name and local host resolve correctly:

# ping -c1 localhost
# ping -c1 `hostname -f` # my_system.domain.com

Successful name resolution results in output similar to the following:

# ping -c1 localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.043 ms

--- localhost ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.043/0.043/0.043/0.000 ms

# ping -c1 `hostname -f`
PING hostname.gateway (XX.XX.XX.XX) 56(84) bytes of data.
64 bytes from hostname.gateway (XX.XX.XX.XX): icmp_seq=1 ttl=64 time=0.019 ms

--- localhost.gateway ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.019/0.019/0.019/0.000 ms

To avoid discrepancies with static and transient host names, set all the host names on the system by entering the following command:
```
# hostnamectl set-hostname name
```

For more information, see the Configuring Host Names Using hostnamectl in the Red Hat Enterprise Linux 7 Networking Guide.

Warning

Name resolution is critical to the operation of Foreman. If Foreman cannot properly resolve its fully qualified domain name, many options fail, such as provisioning.

2. Installing Foreman server

Use the following procedures to install Foreman server and perform the initial configuration.

Note that the Foreman installation script is based on Puppet, which means that if you run the installation script more than once, it might overwrite any manual configuration changes. ⁠ To avoid this and determine which future changes apply, use the --noop argument when you run the installation script. This argument ensures that no actual changes are made. Potential changes are written to /var/log/foreman-installer/foreman.log.

Files are always backed up and so you can revert any unwanted changes. For example, in the foreman-installer logs, you can see an entry similar to the following about Filebucket:

/Stage[main]/Dhcp/File[/etc/dhcp/dhcpd.conf]: Filebucketed /etc/dhcp/dhcpd.conf to puppet with sum 622d9820b8e764ab124367c68f5fa3a1

You can restore the previous file as follows:

# puppet filebucket -l \
restore /etc/dhcp/dhcpd.conf 622d9820b8e764ab124367c68f5fa3a1

2.1. Configuring Repositories

Use this procedure to enable the repositories that are required to install Foreman server. Choose from the available list which operating system and version you are installing on:

Debian 10 (Buster)
Ubuntu 18.04 (Bionic)

2.1.1. Debian 10 (Buster)

Install the ca-certificates package:
```
# apt-get install ca-certificates
```
Change directory to /tmp and install the puppet6-release-buster.deb package:
```
cd /tmp && wget https://apt.puppet.com/puppet6-release-buster.deb
```
Install the puppet6-release-buster.deb package:
```
# dpkg -i /tmp/puppet6-release-buster.deb
```

Enable the Foreman repository:

echo "deb http://deb.theforeman.org/ buster 2.4" | sudo tee /etc/apt/sources.list.d/foreman.list
echo "deb http://deb.theforeman.org/ plugins 2.4" | sudo tee -a /etc/apt/sources.list.d/foreman.list
sudo apt-get -y install ca-certificates gpg
wget -q https://deb.theforeman.org/pubkey.gpg -O- | sudo apt-key add -

2.1.2. Ubuntu 18.04 (Bionic)

Install the ca-certificates package:
```
# apt-get install ca-certificates
```
Change directory to /tmp and install the puppet6-release-bionic.deb package:
```
cd /tmp && wget https://apt.puppet.com/puppet6-release-bionic.deb
```
Install the puppet6-release-bionic.deb package:
```
# dpkg -i /tmp/puppet6-release-bionic.deb
```

Enable the Foreman repository:

echo "deb http://deb.theforeman.org/ bionic 2.4" | sudo tee /etc/apt/sources.list.d/foreman.list
echo "deb http://deb.theforeman.org/ plugins 2.4" | sudo tee -a /etc/apt/sources.list.d/foreman.list
sudo apt-get -y install ca-certificates gpg
wget -q https://deb.theforeman.org/pubkey.gpg -O- | sudo apt-key add -

2.2. Installing Foreman server Packages

Debian 10 (Buster)
Ubuntu 18.04 (Bionic)

2.2.1. Debian 10 (Buster)

Procedure

Update all packages:
```
# apt-get upgrade
```
Install foreman-installer
```
# apt-get install foreman-installer
```

2.2.2. Ubuntu 18.04 (Bionic)

Update all packages:
```
# apt-get upgrade
```
Install foreman-installer
```
# apt-get install foreman-installer
```

2.3. Configuring Foreman server

Install Foreman server using the foreman-installer installation script.

This method is performed by running the installation script with one or more command options. The command options override the corresponding default initial configuration options and are recorded in the Foreman answer file. You can run the script as often as needed to configure any necessary options.

Note	Depending on the options that you use when running the Foreman installer, the configuration can take several minutes to complete.

2.3.1. Configuring Foreman

This initial configuration procedure creates an organization, location, user name, and password. After the initial configuration, you can create additional organizations and locations if required. The initial configuration also installs PostgreSQL databases on the same server.

The installation process can take tens of minutes to complete. If you are connecting remotely to the system, use a utility that allows suspending and reattaching a communication session so that you can check the installation progress in case you become disconnected from the remote system. If you lose connection to the shell where the installation command is running, see the log at /var/log/foreman-installer/foreman.log to determine if the process completed successfully.

Considerations

Use the foreman-installer --scenario foreman --help command to display the available options and any default values. If you do not specify any values, the default values are used.
Specify a meaningful value for the option: --foreman-initial-organization. This can be your company name. An internal label that matches the value is also created and cannot be changed afterwards. If you do not specify a value, an organization called Default Organization with the label Default_Organization is created. You can rename the organization name but not the label.
By default, all configuration files configured by the installer are managed by Puppet. When foreman-installer runs, it overwrites any manual changes to the Puppet managed files with the initial values. By default, Foreman server is installed with the Puppet agent running as a service. If required, you can disable Puppet agent on Foreman server using the --puppet-runmode=none option.
If you want to manage DNS files and DHCP files manually, use the --foreman-proxy-dns-managed=false and --foreman-proxy-dhcp-managed=false options so that Puppet does not manage the files related to the respective services. For more information on how to apply custom configuration on other services, see Applying Custom Configuration to Foreman.

Procedure

Enter the following command with any additional options that you want to use:

# foreman-installer --scenario foreman \
--foreman-initial-organization "initial_organization_name" \
--foreman-initial-location "initial_location_name" \
--foreman-initial-admin-username admin_user_name \
--foreman-initial-admin-password admin_password

The script displays its progress and writes logs to /var/log/foreman-installer/foreman-installer --scenario foreman.log.

3. Performing Additional Configuration on Foreman server

3.1. Enabling Power Management on Managed Hosts

To perform power management tasks on managed hosts using the intelligent platform management interface (IPMI) or a similar protocol, you must enable the baseboard management controller (BMC) module on Foreman server.

Prerequisites

All managed hosts must have a network interface of BMC type. Foreman server uses this NIC to pass the appropriate credentials to the host. For more information, see Adding a Baseboard Management Controller (BMC) Interface in Managing Hosts.

Procedure

To enable BMC, enter the following command:

# foreman-installer --foreman-proxy-bmc "true" \
--foreman-proxy-bmc-default-provider "freeipmi"

3.2. Configuring DNS, DHCP, and TFTP on Foreman server

To configure the DNS, DHCP, and TFTP services on Foreman server, use the foreman-installer command with the options appropriate for your environment. To view a complete list of configurable options, enter the foreman-installer --scenario foreman --help command.

Any changes to the settings require entering the foreman-installer command again. You can enter the command multiple times and each time it updates all configuration files with the changed values.

Adding Multihomed DHCP details

If you want to use Multihomed DHCP, you must inform the installer.

Prerequisites

Ensure that the following information is available to you:
- DHCP IP address ranges
- DHCP gateway IP address
- DHCP nameserver IP address
- DNS information
- TFTP server name
Use the FQDN instead of the IP address where possible in case of network changes.
Contact your network administrator to ensure that you have the correct settings.

Procedure

Enter the foreman-installer command with the options appropriate for your environment. The following example shows configuring full provisioning services:

# foreman-installer --scenario foreman \
--foreman-proxy-dns true \
--foreman-proxy-dns-managed true \
--foreman-proxy-dns-interface eth0 \
--foreman-proxy-dns-zone example.com \
--foreman-proxy-dns-reverse 2.0.192.in-addr.arpa \
--foreman-proxy-dhcp true \
--foreman-proxy-dhcp-managed true \
--foreman-proxy-dhcp-interface eth0 \
--foreman-proxy-dhcp-additional-interfaces eth1 \
--foreman-proxy-dhcp-additional-interfaces eth2 \
--foreman-proxy-dhcp-range "192.0.2.100 192.0.2.150" \
--foreman-proxy-dhcp-gateway 192.0.2.1 \
--foreman-proxy-dhcp-nameservers 192.0.2.2 \
--foreman-proxy-tftp true \
--foreman-proxy-tftp-managed true \
--foreman-proxy-tftp-servername 192.0.2.3

You can monitor the progress of the foreman-installer command displayed in your prompt. You can view the logs in /var/log/foreman-installer/foreman.log. You can view the settings used, including the initial_admin_password parameter, in the /etc/foreman-installer/scenarios.d/foreman-answers.yaml file.

For more information about configuring DHCP, DNS, and TFTP services, see the Configuring Network Services section in the Provisioning Guide.

3.3. Disabling DNS, DHCP, and TFTP for Unmanaged Networks

If you want to manage TFTP, DHCP, and DNS services manually, you must prevent Foreman from maintaining these services on the operating system and disable orchestration to avoid DHCP and DNS validation errors. However, Foreman does not remove the back-end services on the operating system.

Procedure

On Foreman server, enter the following command:

# foreman-installer --foreman-proxy-dhcp false \
--foreman-proxy-dns false \
--foreman-proxy-tftp false

In the Foreman web UI, navigate to Infrastructure > Subnets and select a subnet.
Click the Smart Proxies tab and clear the DHCP Smart Proxy, TFTP Smart Proxy, and Reverse DNS Smart Proxy fields.
Navigate to Infrastructure > Domains and select a domain.
Clear the DNS Smart Proxy field.
Optional: If you use a DHCP service supplied by a third party, configure your DHCP server to pass the following options:
```
Option 66: IP address of Foreman or Smart Proxy
Option 67: /pxelinux.0
```
For more information about DHCP options, see RFC 2132.

Note

Foreman does not perform orchestration when a Smart Proxy is not set for a given subnet and domain. When enabling or disabling Smart Proxy associations, orchestration commands for existing hosts can fail if the expected records and configuration files are not present. When associating a Smart Proxy to turn orchestration on, make sure the required DHCP and DNS records as well as the TFTP files are in place for the existing Foreman hosts in order to prevent host deletion failures in the future.

3.4. Configuring Foreman server for Outgoing Emails

To send email messages from Foreman server, you can use either an SMTP server, or the sendmail command.

Prerequisites

Some SMTP servers with anti-spam protection or grey-listing features are known to cause problems. To setup outgoing email with such a service either install and configure a vanilla SMTP service on Foreman server for relay or use the sendmail command instead.

Procedure

In the Foreman web UI, navigate to Administer → Settings.

Click the Email tab and set the configuration options to match your preferred delivery method. The changes have an immediate effect.

The following example shows the configuration options for using an SMTP server:

Table 8. Using an SMTP server as a delivery method
Name	Example value
Delivery method	SMTP
SMTP address	smtp.example.com
SMTP authentication	login
SMTP HELO/EHLO domain	example.com
SMTP password	password
SMTP port	25
SMTP username	user@example.com

The SMTP username and SMTP password specify the login credentials for the SMTP server.

The following example uses gmail.com as an SMTP server:

Table 9. Using gmail.com as an SMTP server
Name	Example value
Delivery method	SMTP
SMTP address	smtp.gmail.com
SMTP authentication	plain
SMTP HELO/EHLO domain	smtp.gmail.com
SMTP enable StartTLS auto	Yes
SMTP password	password
SMTP port	587
SMTP username	user@gmail.com

The following example uses the sendmail command as a delivery method:

Table 10. Using sendmail as a delivery method

Name Example value

Delivery method

Sendmail

Sendmail arguments

-i -t -G

The Sendmail arguments specify the options passed to the sendmail command. The default value is -i -t. For more information see the sendmail 1 man page.

If you decide to send email using an SMTP server which uses TLS authentication, also perform one of the following steps:
- Mark the CA certificate of the SMTP server as trusted. To do so, execute the following commands on Foreman server:
  # cp mailca.crt /etc/pki/ca-trust/source/anchors/ # update-ca-trust enable # update-ca-trust
  Where mailca.crt is the CA certificate of the SMTP server.
- Alternatively, in the web UI, set the SMTP enable StartTLS auto option to No.
Click Test email to send a test message to the user’s email address to confirm the configuration is working. If a message fails to send, the web UI displays an error. See the log at /var/log/foreman/production.log for further details.

Table 10. Using sendmail as a delivery method
Name	Example value
Delivery method	Sendmail
Sendmail arguments	-i -t -G

Note	For information on configuring email notifications for individual users or user groups, see Configuring Email Notifications in Administering Foreman.

3.5. Tuning Foreman server with Predefined Profiles

If your Foreman deployment includes more than 5000 hosts, you can use predefined tuning profiles to improve performance of Foreman.

Note that you cannot use tuning profiles on Smart Proxies.

You can choose one of the profiles depending on the number of hosts your Foreman manages and available hardware resources.

The tuning profiles are available in the /usr/share/foreman-installer/config/foreman.hiera/tuning/sizes directory.

When you run the foreman-installer command with the --tuning option, deployment configuration settings are applied to Foreman in the following order:

The default tuning profile defined in the /usr/share/foreman-installer/config/foreman.hiera/tuning/common.yaml file
The tuning profile that you want to apply to your deployment and is defined in the /usr/share/foreman-installer/config/foreman.hiera/tuning/sizes/ directory
Optional: If you have configured a /etc/foreman-installer/custom-hiera.yaml file, Foreman applies these configuration settings.

Note that the configuration settings that are defined in the /etc/foreman-installer/custom-hiera.yaml file override the configuration settings that are defined in the tuning profiles.

Therefore, before applying a tuning profile, you must compare the configuration settings that are defined in the default tuning profile in /usr/share/foreman-installer/config/foreman.hiera/tuning/common.yaml, the tuning profile that you want to apply and your /etc/foreman-installer/custom-hiera.yaml file, and remove any duplicated configuration from the /etc/foreman-installer/custom-hiera.yaml file.

default: Number of managed hosts: 0-5000

RAM: 20G

Number of CPU cores: 4
medium: Number of managed hosts: 5001-10000

RAM: 32G

Number of CPU cores: 8
large: Number of managed hosts: 10001-20000

RAM: 64G

Number of CPU cores: 16
extra-large: Number of managed hosts: 20001-60000

RAM: 128G

Number of CPU cores: 32
extra-extra-large: Number of managed hosts: 60000+

RAM: 256G

Number of CPU cores: 48+

Procedure

Optional: If you have configured the custom-hiera.yaml file on Foreman server, back up the /etc/foreman-installer/custom-hiera.yaml file to custom-hiera.original. You can use the backup file to restore the /etc/foreman-installer/custom-hiera.yaml file to its original state if it becomes corrupted:
```
# cp /etc/foreman-installer/custom-hiera.yaml \
/etc/foreman-installer/custom-hiera.original
```
Optional: If you have configured the custom-hiera.yaml file on Foreman server, review the definitions of the default tuning profile in /usr/share/foreman-installer/config/foreman.hiera/tuning/common.yaml and the tuning profile that you want to apply in /usr/share/foreman-installer/config/foreman.hiera/tuning/sizes/. Compare the configuration entries against the entries in your /etc/foreman-installer/custom-hiera.yaml file and remove any duplicated configuration settings in your /etc/foreman-installer/custom-hiera.yaml file.
Enter the foreman-installer command with the --tuning option for the profile that you want to apply. For example, to apply the medium tuning profile settings, enter the following command:
```
# foreman-installer --tuning medium
```

4. Configuring Foreman server with External Services

If you do not want to configure the DNS, DHCP, and TFTP services on Foreman server, use this section to configure your Foreman server to work with external DNS, DHCP and TFTP services.

4.1. Configuring Foreman server with External DNS

You can configure Foreman server with external DNS. Foreman server uses the nsupdate utility to update DNS records on the remote server.

To make any changes persistent, you must enter the foreman-installer command with the options appropriate for your environment.

Prerequisites

You must have a configured external DNS server.

Procedure

Install the bind-utils package:
```
# apt-get install bind9
```
Copy the /etc/rndc.key file from the external DNS server to Foreman server:
```
# scp root@dns.example.com:/etc/rndc.key /etc/rndc.key
```

Configure the ownership, permissions, and SELinux context:

# restorecon -v /etc/rndc.key
# chown -v root:named /etc/rndc.key
# chmod -v 640 /etc/rndc.key

To test the nsupdate utility, add a host remotely:

# echo -e "server DNS_IP_Address\n \
update add aaa.virtual.lan 3600 IN A Host_IP_Address\n \
send\n" | nsupdate -k /etc/rndc.key
# nslookup aaa.virtual.lan DNS_IP_Address
# echo -e "server DNS_IP_Address\n \
update delete aaa.virtual.lan 3600 IN A Host_IP_Address\n \
send\n" | nsupdate -k /etc/rndc.key

Assign the foreman-proxy user to the named group manually. Normally, foreman-installer ensures that the foreman-proxy user belongs to the named UNIX group, however, in this scenario Foreman does not manage users and groups, therefore you need to assign the foreman-proxy user to the named group manually.
```
# usermod -a -G named foreman-proxy
```

Enter the foreman-installer command to make the following persistent changes to the /etc/foreman-proxy/settings.d/dns.yml file:

# foreman-installer --foreman-proxy-dns=true \
--foreman-proxy-dns-managed=false \
--foreman-proxy-dns-provider=nsupdate \
--foreman-proxy-dns-server="DNS_IP_Address" \
--foreman-proxy-keyfile=/etc/rndc.key \
--foreman-proxy-dns-ttl=86400

Restart the foreman-proxy service:
```
# systemctl restart foreman-proxy
```
Log in to Foreman server web UI.
Navigate to Infrastructure > Smart Proxies, locate the Foreman server, and from the list in the Actions column, select Refresh.
Associate the DNS service with the appropriate subnets and domain.

4.2. Configuring Foreman server with External DHCP

To configure Foreman server with external DHCP, you must complete the following procedures:

Configuring an External DHCP Server to Use with Foreman server
Configuring Foreman server with an External DHCP Server

4.2.1. Configuring an External DHCP Server to Use with Foreman server

To configure an external DHCP server to use with Foreman server, on a Red Hat Enterprise Linux server, you must install the ISC DHCP Service and Berkeley Internet Name Domain (BIND) packages. You must also share the DHCP configuration and lease files with Foreman server. The example in this procedure uses the distributed Network File System (NFS) protocol to share the DHCP configuration and lease files.

Note

If you use dnsmasq as an external DHCP server, enable the dhcp-no-override setting. This is required because Foreman creates configuration files on the TFTP server under the grub2/ subdirectory. If the dhcp-no-override setting is disabled, clients fetch the bootloader and its configuration from the root directory, which might cause an error.

If you do not use firewall-cmd to configure the Linux firewall, implement using the command of your choice.

Procedure

On a Red Hat Enterprise Linux Server server, install the ISC DHCP Service and Berkeley Internet Name Domain (BIND) packages:
```
# apt-get install dhcp bind
```
Generate a security token:
```
# dnssec-keygen -a HMAC-MD5 -b 512 -n HOST omapi_key
```
As a result, a key pair that consists of two files is created in the current directory.

Copy the secret hash from the key:

# cat Komapi_key.+*.private |grep ^Key|cut -d ' ' -f2

Edit the dhcpd configuration file for all of the subnets and add the key. The following is an example:

# cat /etc/dhcp/dhcpd.conf
default-lease-time 604800;
max-lease-time 2592000;
log-facility local7;

subnet 192.168.38.0 netmask 255.255.255.0 {
	range 192.168.38.10 192.168.38.100;
	option routers 192.168.38.1;
	option subnet-mask 255.255.255.0;
	option domain-search "virtual.lan";
	option domain-name "virtual.lan";
	option domain-name-servers 8.8.8.8;
}

omapi-port 7911;
key omapi_key {
	algorithm HMAC-MD5;
	secret "jNSE5YI3H1A8Oj/tkV4...A2ZOHb6zv315CkNAY7DMYYCj48Umw==";
};
omapi-key omapi_key;

Note that the option routers value is the Foreman or Smart Proxy IP address that you want to use with an external DHCP service.

Delete the two key files from the directory that they were created in.
On Foreman server, define each subnet. Do not set DHCP Smart Proxy for the defined Subnet yet.

To prevent conflicts, set up the lease and reservation ranges separately. For example, if the lease range is 192.168.38.10 to 192.168.38.100, in the Foreman web UI define the reservation range as 192.168.38.101 to 192.168.38.250.

Configure the firewall for external access to the DHCP server:

# firewall-cmd --add-service dhcp \
&& firewall-cmd --runtime-to-permanent

On Foreman server, determine the UID and GID of the foreman user:
```
# id -u foreman
993
# id -g foreman
990
```
On the DHCP server, create the foreman user and group with the same IDs as determined in a previous step:
```
# groupadd -g 990 foreman
# useradd -u 993 -g 990 -s /sbin/nologin foreman
```

To ensure that the configuration files are accessible, restore the read and execute flags:

# chmod o+rx /etc/dhcp/
# chmod o+r /etc/dhcp/dhcpd.conf
# chattr +i /etc/dhcp/ /etc/dhcp/dhcpd.conf

Start the DHCP service:
```
# systemctl start dhcpd
```

Export the DHCP configuration and lease files using NFS:

# apt-get install nfs-kernel-server nfs-common
# systemctl enable rpcbind nfs-server
# systemctl start rpcbind nfs-server nfs-idmapd

Create directories for the DHCP configuration and lease files that you want to export using NFS:
```
# mkdir -p /exports/var/lib/dhcpd /exports/etc/dhcp
```

To create mount points for the created directories, add the following line to the /etc/fstab file:

/var/lib/dhcpd /exports/var/lib/dhcpd none bind,auto 0 0
/etc/dhcp /exports/etc/dhcp none bind,auto 0 0

Mount the file systems in /etc/fstab:
```
# mount -a
```

Ensure the following lines are present in /etc/exports:

/exports 192.168.38.1(rw,async,no_root_squash,fsid=0,no_subtree_check)

/exports/etc/dhcp 192.168.38.1(ro,async,no_root_squash,no_subtree_check,nohide)

/exports/var/lib/dhcpd 192.168.38.1(ro,async,no_root_squash,no_subtree_check,nohide)

Note that the IP address that you enter is the Foreman or Smart Proxy IP address that you want to use with an external DHCP service.

Reload the NFS server:
```
# exportfs -rva
```

Configure the firewall for the DHCP omapi port 7911:

# firewall-cmd --add-port="7911/tcp" \
&& firewall-cmd --runtime-to-permanent

Optional: Configure the firewall for external access to NFS. Clients are configured using NFSv3.

# firewall-cmd --zone public --add-service mountd \
&& firewall-cmd --zone public --add-service rpc-bind \
&& firewall-cmd --zone public --add-service nfs \
&& firewall-cmd --runtime-to-permanent

4.2.2. Configuring Foreman server with an External DHCP Server

You can configure Foreman server with an external DHCP server.

Prerequisite

Ensure that you have configured an external DHCP server and that you have shared the DHCP configuration and lease files with Foreman server. For more information, see Configuring an External DHCP Server to Use with Foreman server.

Procedure

Install the nfs-utils utility:

# apt-get install nfs-kernel-server nfs-common

Create the DHCP directories for NFS:

# mkdir -p /mnt/nfs/etc/dhcp /mnt/nfs/var/lib/dhcpd

Change the file owner:
```
# chown -R foreman-proxy /mnt/nfs
```
Verify communication with the NFS server and the Remote Procedure Call (RPC) communication paths:
```
# showmount -e DHCP_Server_FQDN
# rpcinfo -p DHCP_Server_FQDN
```

Add the following lines to the /etc/fstab file:

DHCP_Server_FQDN:/exports/etc/dhcp /mnt/nfs/etc/dhcp nfs
ro,vers=3,auto,nosharecache,context="system_u:object_r:dhcp_etc_t:s0" 0 0

DHCP_Server_FQDN:/exports/var/lib/dhcpd /mnt/nfs/var/lib/dhcpd nfs
ro,vers=3,auto,nosharecache,context="system_u:object_r:dhcpd_state_t:s0" 0 0

Mount the file systems on /etc/fstab:
```
# mount -a
```

To verify that the foreman-proxy user can access the files that are shared over the network, display the DHCP configuration and lease files:

# su foreman-proxy -s /bin/bash
bash-4.2$ cat /mnt/nfs/etc/dhcp/dhcpd.conf
bash-4.2$ cat /mnt/nfs/var/lib/dhcpd/dhcpd.leases
bash-4.2$ exit

Enter the foreman-installer command to make the following persistent changes to the /etc/foreman-proxy/settings.d/dhcp.yml file:

# foreman-installer --foreman-proxy-dhcp=true \
--foreman-proxy-dhcp-provider=remote_isc \
--foreman-proxy-plugin-dhcp-remote-isc-dhcp-config /mnt/nfs/etc/dhcp/dhcpd.conf \
--foreman-proxy-plugin-dhcp-remote-isc-dhcp-leases /mnt/nfs/var/lib/dhcpd/dhcpd.leases \
--foreman-proxy-plugin-dhcp-remote-isc-key-name=omapi_key \
--foreman-proxy-plugin-dhcp-remote-isc-key-secret=jNSE5YI3H1A8Oj/tkV4...A2ZOHb6zv315CkNAY7DMYYCj48Umw== \
--foreman-proxy-plugin-dhcp-remote-isc-omapi-port=7911 \
--enable-foreman-proxy-plugin-dhcp-remote-isc \
--foreman-proxy-dhcp-server=DHCP_Server_FQDN

Restart the foreman-proxy service:
```
# systemctl restart foreman-proxy
```
Log in to Foreman server web UI.
Navigate to Infrastructure > Smart Proxies, locate the Foreman server, and from the list in the Actions column, select Refresh.
Associate the DHCP service with the appropriate subnets and domain.

4.3. Configuring Foreman server with External TFTP

You can configure Foreman server with external TFTP services.

Procedure

Create the TFTP directory for NFS:
```
# mkdir -p /mnt/nfs/var/lib/tftpboot
```

In the /etc/fstab file, add the following line:

TFTP_Server_IP_Address:/exports/var/lib/tftpboot /mnt/nfs/var/lib/tftpboot nfs rw,vers=3,auto,nosharecache,context="system_u:object_r:tftpdir_rw_t:s0" 0 0

Mount the file systems in /etc/fstab:
```
# mount -a
```
Enter the foreman-installer command to make the following persistent changes to the /etc/foreman-proxy/settings.d/tftp.yml file:
```
# foreman-installer --foreman-proxy-tftp=true \
--foreman-proxy-tftp-root /mnt/nfs/var/lib/tftpboot
```
If the TFTP service is running on a different server than the DHCP service, update the tftp_servername setting with the FQDN or IP address of the server that the TFTP service is running on:
```
# foreman-installer --foreman-proxy-tftp-servername=TFTP_Server_FQDN
```
Log in to Foreman server web UI.
Navigate to Infrastructure > Smart Proxies, locate the Foreman server, and from the list in the Actions column, select Refresh.
Associate the TFTP service with the appropriate subnets and domain.

4.4. Configuring Foreman server with External IdM DNS

When Foreman server adds a DNS record for a host, it first determines which Smart Proxy is providing DNS for that domain. It then communicates with the Smart Proxy that is configured to provide DNS service for your deployment and adds the record. The hosts are not involved in this process. Therefore, you must install and configure the IdM client on the Foreman or Smart Proxy that is currently configured to provide a DNS service for the domain you want to manage using the IdM server.

Foreman server can be configured to use a Red Hat Identity Management (IdM) server to provide DNS service. For more information about Red Hat Identity Management, see the Linux Domain Identity, Authentication, and Policy Guide.

To configure Foreman server to use a Red Hat Identity Management (IdM) server to provide DNS service, use one of the following procedures:

Configuring Dynamic DNS Update with GSS-TSIG Authentication
Configuring Dynamic DNS Update with TSIG Authentication

To revert to internal DNS service, use the following procedure:

Reverting to Internal DNS Service

Note

You are not required to use Foreman server to manage DNS. When you are using the realm enrollment feature of Foreman, where provisioned hosts are enrolled automatically to IdM, the ipa-client-install script creates DNS records for the client. Configuring Foreman server with external IdM DNS and realm enrollment are mutually exclusive. For more information about configuring realm enrollment, see External Authentication for Provisioned Hosts in Administering Foreman.

4.4.1. Configuring Dynamic DNS Update with GSS-TSIG Authentication

You can configure the IdM server to use the generic security service algorithm for secret key transaction (GSS-TSIG) technology defined in RFC3645. To configure the IdM server to use the GSS-TSIG technology, you must install the IdM client on the Foreman server base operating system.

Prerequisites

You must ensure the IdM server is deployed and the host-based firewall is configured correctly. For more information, see Port Requirements in the Linux Domain Identity, Authentication, and Policy Guide.
You must contact the IdM server administrator to ensure that you obtain an account on the IdM server with permissions to create zones on the IdM server.
You must confirm whether Foreman server or Smart Proxy server is configured to provide DNS service for your deployment.
You must configure DNS, DHCP and TFTP services on the base operating system of either the Foreman or Smart Proxy that is managing the DNS service for your deployment.
You must create a backup of the answer file. You can use the backup to restore the answer file to its original state if it becomes corrupted. For more information, see Configuring Foreman server.

Procedure

To configure dynamic DNS update with GSS-TSIG authentication, complete the following steps:

Creating a Kerberos Principal on the IdM Server

Obtain a Kerberos ticket for the account obtained from the IdM administrator:
```
# kinit idm_user
```
Create a new Kerberos principal for Foreman server to use to authenticate on the IdM server.
```
# ipa service-add foreman.example.com
```

Installing and Configuring the IdM Client

On the base operating system of either the Foreman or Smart Proxy that is managing the DNS service for your deployment, install the ipa-client package:
```
# apt-get install ipa-client
```
Configure the IdM client by running the installation script and following the on-screen prompts:
```
# ipa-client-install
```
Obtain a Kerberos ticket:
```
# kinit admin
```
Remove any preexisting keytab:
```
# rm /etc/foreman-proxy/dns.keytab
```

Obtain the keytab for this system:

# ipa-getkeytab -p smart-proxy/foreman.example.com@EXAMPLE.COM \
-s idm1.example.com -k /etc/foreman-proxy/dns.keytab

Note	When adding a keytab to a standby system with the same host name as the original system in service, add the `r` option to prevent generating new credentials and rendering the credentials on the original system invalid.

For the dns.keytab file, set the group and owner to foreman-proxy:

# chown foreman-proxy:foreman-proxy /etc/foreman-proxy/dns.keytab

Optional: To verify that the keytab file is valid, enter the following command:

# kinit -kt /etc/foreman-proxy/dns.keytab \
smart-proxy/foreman.example.com@EXAMPLE.COM

Configuring DNS Zones in the IdM web UI

Create and configure the zone that you want to manage:
1. Navigate to Network Services > DNS > DNS Zones.
2. Select Add and enter the zone name. For example, example.com.
3. Click Add and Edit.
4. Click the Settings tab and in the BIND update policy box, add the following to the semi-colon separated list:
  grant smart-proxy/047foreman.example.com@EXAMPLE.COM wildcard * ANY;
5. Set Dynamic update to True.
6. Enable Allow PTR sync.
7. Click Save to save the changes.
Create and configure the reverse zone:
1. Navigate to Network Services > DNS > DNS Zones.
2. Click Add.
3. Select Reverse zone IP network and add the network address in CIDR format to enable reverse lookups.
4. Click Add and Edit.
5. Click the Settings tab and in the BIND update policy box, add the following to the semi-colon separated list:
  grant smart-proxy\047foreman.example.com@EXAMPLE.COM wildcard * ANY;
6. Set Dynamic update to True.
7. Click Save to save the changes.

Configuring the Foreman or Smart Proxy server that Manages the DNS Service for the Domain

Use the foreman-installer command to configure the Foreman or Smart Proxy that manages the DNS Service for the domain:

On Foreman, enter the following command:

foreman-installer --scenario foreman \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=true \
--foreman-proxy-dns-provider=nsupdate_gss \
--foreman-proxy-dns-server="idm1.example.com" \
--foreman-proxy-dns-tsig-principal="smart-proxy/foreman.example.com@EXAMPLE.COM" \
--foreman-proxy-dns-tsig-keytab=/etc/foreman-proxy/dns.keytab \
--foreman-proxy-dns-reverse="55.168.192.in-addr.arpa" \
--foreman-proxy-dns-zone=example.com \
--foreman-proxy-dns-ttl=86400

On Smart Proxy, enter the following command:

foreman-installer --no-enable-foreman \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=true \
--foreman-proxy-dns-provider=nsupdate_gss \
--foreman-proxy-dns-server="idm1.example.com" \
--foreman-proxy-dns-tsig-principal="smart-proxy/foreman.example.com@EXAMPLE.COM" \
--foreman-proxy-dns-tsig-keytab=/etc/foreman-proxy/dns.keytab \
--foreman-proxy-dns-reverse="55.168.192.in-addr.arpa" \
--foreman-proxy-dns-zone=example.com \
--foreman-proxy-dns-ttl=86400

Restart the Foreman or Smart Proxy’s Proxy Service.
```
# systemctl restart foreman-proxy
```

After you run the foreman-installer command to make any changes to your Smart Proxy configuration, you must update the configuration of each affected Smart Proxy in the Foreman web UI.

Updating the Configuration in the Foreman web UI

Navigate to Infrastructure > Smart Proxies, locate the Foreman server, and from the list in the Actions column, select Refresh.
Configure the domain:
1. Navigate to Infrastructure > Domains and select the domain name.
2. In the Domain tab, ensure DNS Smart Proxy is set to the Smart Proxy where the subnet is connected.
Configure the subnet:
1. Navigate to Infrastructure > Subnets and select the subnet name.
2. In the Subnet tab, set IPAM to None.
3. In the Domains tab, select the domain that you want to manage using the IdM server.
4. In the Smart Proxies tab, ensure Reverse DNS Smart Proxy is set to the Smart Proxy where the subnet is connected.
5. Click Submit to save the changes.

4.4.2. Configuring Dynamic DNS Update with TSIG Authentication

You can configure an IdM server to use the secret key transaction authentication for DNS (TSIG) technology that uses the rndc.key key file for authentication. The TSIG protocol is defined in RFC2845.

Prerequisites

You must ensure the IdM server is deployed and the host-based firewall is configured correctly. For more information, see Port Requirements in the Linux Domain Identity, Authentication, and Policy Guide.
You must obtain root user access on the IdM server.
You must confirm whether Foreman server or Smart Proxy server is configured to provide DNS service for your deployment.
You must configure DNS, DHCP and TFTP services on the base operating system of either the Foreman or Smart Proxy that is managing the DNS service for your deployment.
You must create a backup of the answer file. You can use the backup to restore the answer file to its original state if it becomes corrupted. For more information, see Configuring Foreman server.

Procedure

To configure dynamic DNS update with TSIG authentication, complete the following steps:

Enabling External Updates to the DNS Zone in the IdM Server

On the IdM Server, add the following to the top of the /etc/named.conf file:

########################################################################

include "/etc/rndc.key";
controls  {
inet _IdM_Server_IP_Address_ port 953 allow { _Foreman_IP_Address_; } keys { "rndc-key"; };
};
########################################################################

Reload the named service to make the changes take effect:
```
# systemctl reload named
```
In the IdM web UI, navigate to Network Services > DNS > DNS Zones and click the name of the zone. In the Settings tab, apply the following changes:
1. Add the following in the BIND update policy box:
  grant "rndc-key" zonesub ANY;
2. Set Dynamic update to True.
3. Click Update to save the changes.
Copy the /etc/rndc.key file from the IdM server to the base operating system of your Foreman server. Enter the following command:
```
# scp /etc/rndc.key root@satellite.example.com:/etc/rndc.key
```
To set the correct ownership, permissions, and SELinux context for the rndc.key file, enter the following command:
```
# restorecon -v /etc/rndc.key
# chown -v root:named /etc/rndc.key
# chmod -v 640 /etc/rndc.key
```
Assign the foreman-proxy user to the named group manually. Normally, foreman-installer ensures that the foreman-proxy user belongs to the named UNIX group, however, in this scenario Foreman does not manage users and groups, therefore you need to assign the foreman-proxy user to the named group manually.
```
# usermod -a -G named foreman-proxy
```

On Foreman server, enter the following satellite-installer command to configure Foreman to use the external DNS server:

# foreman-installer --scenario foreman \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=false \
--foreman-proxy-dns-provider=nsupdate \
--foreman-proxy-dns-server="IdM_Server_IP_Address" \
--foreman-proxy-keyfile=/etc/rndc.key \
--foreman-proxy-dns-ttl=86400

Testing External Updates to the DNS Zone in the IdM Server

Install the bind-utils package:
```
# apt-get install bind9
```
Ensure that the key in the /etc/rndc.key file on Foreman server is the same key file that is used on the IdM server:
```
key "rndc-key" {
        algorithm hmac-md5;
        secret "secret-key==";
};
```
On Foreman server, create a test DNS entry for a host. For example, host test.example.com with an A record of 192.168.25.20 on the IdM server at 192.168.25.1.
```
# echo -e "server 192.168.25.1\n \
update add test.example.com 3600 IN A 192.168.25.20\n \
send\n" | nsupdate -k /etc/rndc.key
```

On Foreman server, test the DNS entry:

# nslookup test.example.com 192.168.25.1
Server:		192.168.25.1
Address:	192.168.25.1#53

Name:	test.example.com
Address: 192.168.25.20

To view the entry in the IdM web UI, navigate to Network Services > DNS > DNS Zones. Click the name of the zone and search for the host by name.

If resolved successfully, remove the test DNS entry:

# echo -e "server 192.168.25.1\n \
update delete test.example.com 3600 IN A 192.168.25.20\n \
send\n" | nsupdate -k /etc/rndc.key

Confirm that the DNS entry was removed:
```
# nslookup test.example.com 192.168.25.1
```
The above nslookup command fails and returns the SERVFAIL error message if the record was successfully deleted.

4.4.3. Reverting to Internal DNS Service

You can revert to using Foreman server and Smart Proxy server as your DNS providers. You can use a backup of the answer file that was created before configuring external DNS, or you can create a backup of the answer file. For more information about answer files, see Configuring Foreman server.

Procedure

On the Foreman or Smart Proxy server that you want to configure to manage DNS service for the domain, complete the following steps:

Configuring Foreman or Smart Proxy as a DNS Server

If you have created a backup of the answer file before configuring external DNS, restore the answer file and then enter the foreman-installer command:
```
# foreman-installer
```
If you do not have a suitable backup of the answer file, create a backup of the answer file now. To configure Foreman or Smart Proxy as DNS server without using an answer file, enter the following foreman-installer command on Foreman and each affected Smart Proxy:
```
# foreman-installer \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=true \
--foreman-proxy-dns-provider=nsupdate \
--foreman-proxy-dns-server="127.0.0.1"  \
--foreman-proxy-dns-tsig-principal="foremanproxy/foreman.example.com@EXAMPLE.COM" \
--foreman-proxy-dns-tsig-keytab=/etc/foreman-proxy/dns.keytab
```
For more information,see Configuring DNS, DHCP, and TFTP on Smart Proxy server.

After you run the foreman-installer command to make any changes to your Smart Proxy configuration, you must update the configuration of each affected Smart Proxy in the Foreman web UI.

Updating the Configuration in the Foreman web UI

Navigate to Infrastructure > Smart Proxies.
For each Smart Proxy that you want to update, from the Actions list, select Refresh.
Configure the domain:
1. Navigate to Infrastructure > Domains and click the domain name that you want to configure.
2. In the Domain tab, set DNS Smart Proxy to the Smart Proxy where the subnet is connected.
Configure the subnet:
1. Navigate to Infrastructure > Subnets and select the subnet name.
2. In the Subnet tab, set IPAM to DHCP or Internal DB.
3. In the Domains tab, select the domain that you want to manage using Foreman or Smart Proxy.
4. In the Smart Proxies tab, set Reverse DNS Smart Proxy to the Smart Proxy where the subnet is connected.
5. Click Submit to save the changes.

Appendix A: Applying Custom Configuration to Foreman

When you install and configure Foreman for the first time using foreman-installer, you can specify that the DNS and DHCP configuration files are not to be managed by Puppet using the installer flags --foreman-proxy-dns-managed=false and --foreman-proxy-dhcp-managed=false. If these flags are not specified during the initial installer run, rerunning of the installer overwrites all manual changes, for example, rerun for upgrade purposes. If changes are overwritten, you must run the restore procedure to restore the manual changes. For more information, see Restoring Manual Changes Overwritten by a Puppet Run.

To view all installer flags available for custom configuration, run foreman-installer --scenario foreman --full-help. Some Puppet classes are not exposed to the Foreman installer. To manage them manually and prevent the installer from overwriting their values, specify the configuration values by adding entries to configuration file /etc/foreman-installer/custom-hiera.yaml. This configuration file is in YAML format, consisting of one entry per line in the format of <puppet class>::<parameter name>: <value>. Configuration values specified in this file persist across installer reruns.

Common examples include:

For Apache, to set the ServerTokens directive to only return the Product name:
```
apache::server_tokens: Prod
```
To turn off the Apache server signature entirely:
```
apache::server_signature: Off
```

The Puppet modules for the Foreman installer are stored under /usr/share/foreman-installer/modules. Check the .pp files (for example: moduleName/manifests/example.pp) to look up the classes, parameters, and values. Alternatively, use the grep command to do keyword searches.

Setting some values may have unintended consequences that affect the performance or functionality of Foreman. Consider the impact of the changes before you apply them, and test the changes in a non-production environment first. If you do not have a non-production Foreman environment, run the Foreman installer with the --noop and --verbose options. If your changes cause problems, remove the offending lines from custom-hiera.yaml and rerun the Foreman installer. If you have any specific questions about whether a particular value is safe to alter, contact Red Hat support.

Appendix B: Restoring Manual Changes Overwritten by a Puppet Run

If your manual configuration has been overwritten by a Puppet run, you can restore the files to the previous state. The following example shows you how to restore a DHCP configuration file overwritten by a Puppet run.

Procedure

Copy the file you intend to restore. This allows you to compare the files to check for any mandatory changes required by the upgrade. This is not common for DNS or DHCP services.
```
# cp /etc/dhcp/dhcpd.conf /etc/dhcp/dhcpd.backup
```

Check the log files to note down the md5sum of the overwritten file. For example:

# journalctl -xe
...
/Stage[main]/Dhcp/File[/etc/dhcp/dhcpd.conf]: Filebucketed /etc/dhcp/dhcpd.conf to puppet with sum 622d9820b8e764ab124367c68f5fa3a1
...

Restore the overwritten file:

# puppet filebucket restore --local --bucket \
/var/lib/puppet/clientbucket /etc/dhcp/dhcpd.conf \ 622d9820b8e764ab124367c68f5fa3a1

Compare the backup file and the restored file, and edit the restored file to include any mandatory changes required by the upgrade.