1. Load balancing solution architecture

You can configure Foreman server to use a load balancer to distribute client requests and network load across multiple Smart Proxy servers. This results in an overall performance improvement on Smart Proxy servers.

This guide outlines how to prepare Foreman server and Smart Proxy server for load balancing, and provides guidelines on how to configure a load balancer and register clients in a load-balanced setup.

A load-balanced setup consists of the following components:

  • Foreman server

  • Two or more Smart Proxy servers

  • A load balancer

  • Multiple clients

Load balancing solution architecture
Figure 1. Foreman load balancing solution architecture

In a load-balanced setup, nearly all Smart Proxy functionality continues to work as expected when one Smart Proxy server is down, for planned or unplanned maintenance. A load balancer works with the following services and features:

  • Registration using subscription-manager

  • Content management with Yum repositories

  • Optional: Puppet

Note

In the load-balanced setup, a load balancer distributes load only for the services and features mentioned above. If other services, such as provisioning or virt-who, are running on the individual Smart Proxies, you must access them directly through Smart Proxies and not through the load balancer.
Managing Puppet limitations

Puppet Certificate Authority (CA) management does not support certificate signing in a load-balanced setup. Puppet CA stores certificate information, such as the serial number counter and CRL, on the file system. Multiple writer processes that attempt to use the same data can corrupt it.

To manage this Puppet limitation, complete the following steps:

  1. Configure Puppet certificate signing on one Smart Proxy server, typically the first system where you configure Smart Proxy server for load balancing.

  2. Configure the clients to send CA requests to port 8141 on a load balancer.

  3. Configure a load balancer to redirect CA requests from port 8141 to port 8140 on the system where you configure Smart Proxy server to sign Puppet certificates.

2. Load balancing considerations

Distributing load between several Smart Proxy servers prevents any one Smart Proxy from becoming a single point of failure. Configuring Smart Proxies to use a load balancer can provide resilience against planned and unplanned outages. This improves availability and responsiveness.

Consider the following guidelines when configuring load balancing:

  • If you use Puppet, Puppet certificate signing is assigned to the first Smart Proxy that you configure. If the first Smart Proxy is down, clients cannot obtain Puppet content.

  • This solution does not use Pacemaker or other similar HA tools to maintain one state across all Smart Proxies. To troubleshoot issues, reproduce the issue on each Smart Proxy, bypassing the load balancer.

Additional maintenance required for load balancing

Configuring Smart Proxies to use a load balancer results in a more complex environment and requires additional maintenance.

The following additional steps are required for load balancing:

  • You must ensure that all Smart Proxies have the same content views and synchronize all Smart Proxies to the same content view versions

  • You must upgrade each Smart Proxy in sequence

  • You must backup each Smart Proxy that you configure regularly

Upgrading Smart Proxy servers in a load balancing configuration

There are no additional steps required for Smart Proxy servers in a load balancing configuration.

3. Prerequisites for configuring Smart Proxy servers for load balancing

To configure Smart Proxy servers for load balancing, complete the following procedures described in Installing a Smart Proxy Server 3.9 on CentOS/RHEL. Foreman does not support configuring existing Smart Proxy servers for load balancing.

  1. Registering Smart Proxy server to Foreman server

  2. Attaching the Foreman Infrastructure Subscription

  3. Configuring Repositories

  4. Synchronizing the System Clock With chronyd

  5. Installing Smart Proxy server Packages

4. Configuring Smart Proxy servers for load balancing

This chapter outlines how to configure Smart Proxy servers for load balancing. Proceed to one of the following sections depending on your Foreman server configuration:

Use different file names for the Katello certificates you create for each Smart Proxy server. For example, name the certificate archive file with Smart Proxy server FQDN.

4.1. Configuring Smart Proxy server with default SSL certificates for load balancing without Puppet

The following section describes how to configure Smart Proxy servers that use default SSL certificates for load balancing without Puppet. Complete this procedure on each Smart Proxy server that you want to configure for load balancing.

Procedure

  1. On Foreman server, generate Katello certificates for Smart Proxy server:

    # foreman-proxy-certs-generate \
--certs-tar "/root/smartproxy.example.com-certs.tar" \
--foreman-proxy-cname loadbalancer.example.com \
--foreman-proxy-fqdn smartproxy.example.com

    Retain a copy of the example foreman-installer command that is output by the foreman-proxy-certs-generate command for installing Smart Proxy server certificate.

  2. Copy the certificate archive file from Foreman server to Smart Proxy server.

    # scp /root/smartproxy.example.com-certs.tar root@smartproxy.example.com:/root/smartproxy.example.com-certs.tar

  3. Append the following options to the foreman-installer command that you obtain from the output of the foreman-proxy-certs-generate command:

    --certs-cname "loadbalancer.example.com" \
--enable-foreman-proxy-plugin-remote-execution-script

  4. On Smart Proxy server, enter the foreman-installer command:

    # foreman-installer --scenario foreman-proxy-content \
--certs-cname "loadbalancer.example.com" \
--certs-tar-file "smartproxy.example.com-certs.tar" \
--enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-foreman-base-url "https://foreman.example.com" \
--foreman-proxy-oauth-consumer-key "oauth key" \
--foreman-proxy-oauth-consumer-secret "oauth secret" \
--foreman-proxy-register-in-foreman "true" \
--foreman-proxy-trusted-hosts "foreman.example.com" \
--foreman-proxy-trusted-hosts "smartproxy.example.com"

4.2. Configuring Smart Proxy server with default SSL certificates for load balancing with Puppet

The following section describes how to configure Smart Proxy servers that use default SSL certificates for load balancing with Puppet.

If you use Puppet in your Foreman configuration, you must complete the following procedures:

  1. Configuring Smart Proxy server with default SSL certificates to generate and sign Puppet certificates

  2. Configuring remaining Smart Proxy servers with default SSL certificates for load balancing

4.2.1. Configuring Smart Proxy server with default SSL certificates to generate and sign Puppet certificates

Complete this procedure only for the system where you want to configure Smart Proxy server to generate and sign Puppet certificates for all other Smart Proxy servers that you configure for load balancing.

Procedure

  1. On Foreman server, generate Katello certificates for the system where you configure Smart Proxy server to generate and sign Puppet certificates:

    # foreman-proxy-certs-generate \
--certs-tar "/root/smart-proxy-ca.example.com-certs.tar" \
--foreman-proxy-cname loadbalancer.example.com \
--foreman-proxy-fqdn smart-proxy-ca.example.com

    Retain a copy of the example foreman-installer command that is output by the foreman-proxy-certs-generate command for installing Smart Proxy server certificate.

  2. Copy the certificate archive file from Foreman server to Smart Proxy server:

    # scp /root/smart-proxy-ca.example.com-certs.tar root@smart-proxy-ca.example.com:smart-proxy-ca.example.com-certs.tar

  3. Append the following options to the foreman-installer command that you obtain from the output of the foreman-proxy-certs-generate command:

    --certs-cname "loadbalancer.example.com" \
--enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-puppetca "true" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server-ca "true"

  4. On Smart Proxy server, enter the foreman-installer command:

    # foreman-installer --scenario foreman-proxy-content \
--certs-cname "loadbalancer.example.com" \
--certs-tar-file "smart-proxy-ca.example.com-certs.tar" \
--enable-foreman-proxy-plugin-remote-execution-script \
--enable-puppet \
--foreman-proxy-foreman-base-url "https://foreman.example.com" \
--foreman-proxy-oauth-consumer-key "oauth key" \
--foreman-proxy-oauth-consumer-secret "oauth secret" \
--foreman-proxy-puppetca "true" \
--foreman-proxy-register-in-foreman "true" \
--foreman-proxy-trusted-hosts "foreman.example.com" \
--foreman-proxy-trusted-hosts "smart-proxy-ca.example.com" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server true \
--puppet-server-ca "true"

  5. On Smart Proxy server, stop the Puppet server:

    # puppet resource service puppetserver ensure=stopped

  6. Generate Puppet certificates for all other Smart Proxy servers that you configure for load balancing, except the first system where you configure Puppet certificates signing:

    # puppetserver ca generate \
--ca-client \
--certname smartproxy.example.com \
--subject-alt-names loadbalancer.example.com

    This command creates the following files on the system where you configure Smart Proxy server to sign Puppet certificates:

    • /etc/puppetlabs/puppet/ssl/certs/smartproxy.example.com.pem

    • /etc/puppetlabs/puppet/ssl/certs/ca.pem

    • /etc/puppetlabs/puppet/ssl/private_keys/smartproxy.example.com.pem

    • /etc/puppetlabs/puppet/ssl/public_keys/smartproxy.example.com.pem

  7. Resume the Puppet server:

    # puppet resource service puppetserver ensure=running

4.2.2. Configuring remaining Smart Proxy servers with default SSL certificates for load balancing

Complete this procedure on each Smart Proxy server excluding the system where you configure Smart Proxy server to sign Puppet certificates.

Procedure

  1. On Foreman server, generate Katello certificates for Smart Proxy server:

    # foreman-proxy-certs-generate \
--certs-tar "/root/smartproxy.example.com-certs.tar" \
--foreman-proxy-cname loadbalancer.example.com \
--foreman-proxy-fqdn smartproxy.example.com

    Retain a copy of the example foreman-installer command that is output by the foreman-proxy-certs-generate command for installing Smart Proxy server certificate.

  2. Copy the certificate archive file from Foreman server to Smart Proxy server:

    # scp /root/smartproxy.example.com-certs.tar root@smartproxy.example.com:/root/smartproxy.example.com-certs.tar

  3. On Smart Proxy server, install the puppetserver package:

    # dnf install puppetserver

  4. On Smart Proxy server, create directories for puppet certificates:

    # mkdir -p /etc/puppetlabs/puppet/ssl/certs/ \
/etc/puppetlabs/puppet/ssl/private_keys/ \
/etc/puppetlabs/puppet/ssl/public_keys/

  5. On Smart Proxy server, copy the Puppet certificates for this Smart Proxy server from the system where you configure Smart Proxy server to sign Puppet certificates:

    # scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/certs/smartproxy.example.com.pem /etc/puppetlabs/puppet/ssl/certs/smartproxy.example.com.pem
# scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/certs/ca.pem /etc/puppetlabs/puppet/ssl/certs/ca.pem
# scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/private_keys/smartproxy.example.com.pem /etc/puppetlabs/puppet/ssl/private_keys/smartproxy.example.com.pem
# scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/public_keys/smartproxy.example.com.pem /etc/puppetlabs/puppet/ssl/public_keys/smartproxy.example.com.pem

  6. On Smart Proxy server, change the /etc/puppetlabs/puppet/ssl/ directory ownership to user puppet and group puppet:

    # chown -R puppet:puppet /etc/puppetlabs/puppet/ssl/

  7. On Smart Proxy server, set the SELinux context for the /etc/puppetlabs/puppet/ssl/ directory:

    # restorecon -Rv /etc/puppetlabs/puppet/ssl/

  8. Append the following options to the foreman-installer command that you obtain from the output of the foreman-proxy-certs-generate command:

    --certs-cname "loadbalancer.example.com" \
--enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-puppetca "false" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server-ca "false"

  9. On Smart Proxy server, enter the foreman-installer command:

    # foreman-installer --scenario foreman-proxy-content \
--certs-cname "loadbalancer.example.com" \
--certs-tar-file "smartproxy.example.com-certs.tar" \
--enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-foreman-base-url "https://foreman.example.com" \
--foreman-proxy-oauth-consumer-key "oauth key" \
--foreman-proxy-oauth-consumer-secret "oauth secret" \
--foreman-proxy-puppetca "false" \
--foreman-proxy-register-in-foreman "true" \
--foreman-proxy-trusted-hosts "foreman.example.com" \
--foreman-proxy-trusted-hosts "smartproxy.example.com" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server-ca "false"

4.3. Configuring Smart Proxy server with custom SSL certificates for load balancing without Puppet

The following section describes how to configure Smart Proxy servers that use custom SSL certificates for load balancing without Puppet.

4.3.1. Creating a custom SSL certificate for Smart Proxy server

This procedure outlines how to create a configuration file for the Certificate Signing Request and include the load balancer and Smart Proxy server as Subject Alternative Names (SAN). Complete this procedure on each Smart Proxy server that you want to configure for load balancing.

Procedure

  1. To store all the source certificate files, create a directory that is accessible only to the root user:

    # mkdir /root/smart-proxy_cert

  2. Create a private key with which to sign the certificate signing request (CSR).

    Note that the private key must be unencrypted. If you use a password-protected private key, remove the private key password.

    If you already have a private key for this Smart Proxy server, skip this step.

    # openssl genrsa -out /root/smart-proxy_cert/smart-proxy_cert_key.pem 4096

  3. Create the /root/smart-proxy_cert/openssl.cnf configuration file for the CSR and include the following content:

    [ req ]
req_extensions = v3_req
distinguished_name = req_distinguished_name
x509_extensions = usr_cert
prompt = no

[ req_distinguished_name ]
commonName = smartproxy.example.com (1)

[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
extendedKeyUsage = serverAuth, clientAuth, codeSigning, emailProtection
subjectAltName = @alt_names

[alt_names] (2)
DNS.1 = loadbalancer.example.com
DNS.2 = smartproxy.example.com

    1. The certificate’s common name must match the FQDN of Smart Proxy server. Ensure to change this when running the command on each Smart Proxy server that you configure for load balancing. You can also set a wildcard value *. If you set a wildcard value, you must add the -t foreman-proxy option when you use the katello-certs-check command.

    2. Under [alt_names], include the FQDN of the load balancer as DNS.1 and the FQDN of Smart Proxy server as DNS.2.

  4. Optional: If you want to add Distinguished Name (DN) details to the CSR, add the following information to the [ req_distinguished_name ] section:

    [req_distinguished_name]
CN = smartproxy.example.com
countryName =My_Country_Name (1)
stateOrProvinceName = My_State_Or_Province_Name (2)
localityName = My_Locality_Name (3)
organizationName = My_Organization_Or_Company_Name
organizationalUnitName = My_Organizational_Unit_Name (4)

    1. Two letter code

    2. Full name

    3. Full name (example: New York)

    4. Division responsible for the certificate (example: IT department)

  5. Generate CSR:

    # openssl req -new \
-key /root/smart-proxy_cert/smart-proxy_cert_key.pem \ (1)
-config /root/smart-proxy_cert/openssl.cnf \ (2)
-out /root/smart-proxy_cert/smart-proxy_cert_csr.pem (3)

    1. Path to the private key

    2. Path to the configuration file

    3. Path to the CSR to generate

  6. Send the certificate signing request to the certificate authority (CA). The same CA must sign certificates for Foreman server and Smart Proxy server.

    When you submit the request, specify the lifespan of the certificate. The method for sending the certificate request varies, so consult the CA for the preferred method. In response to the request, you can expect to receive a CA bundle and a signed certificate, in separate files.

  7. Copy the Certificate Authority bundle and Smart Proxy server certificate file that you receive from the Certificate Authority, and Smart Proxy server private key to your Foreman server.

  8. On Foreman server, validate Smart Proxy server certificate input files:

    # katello-certs-check \
-c /root/smart-proxy_cert/smart-proxy_cert.pem \ (1)
-k /root/smart-proxy_cert/smart-proxy_cert_key.pem \ (2)
-b /root/smart-proxy_cert/ca_cert_bundle.pem (3)

    1. Smart Proxy server certificate file, provided by your Certificate Authority

    2. Smart Proxy server’s private key that you used to sign the certificate

    3. Certificate Authority bundle, provided by your Certificate Authority

      If you set the commonName= to a wildcard value *, you must add the -t foreman-proxy option to the katello-certs-check command.

      Retain a copy of the example foreman-proxy-certs-generate command that is output by the katello-certs-check command for creating the Certificate Archive File for this Smart Proxy server.

4.3.2. Configuring Smart Proxy server with custom SSL certificates for load balancing without Puppet

The following section describes how to configure Smart Proxy servers that use custom SSL certificates for load balancing without Puppet. Complete this procedure on each Smart Proxy server that you want to configure for load balancing.

Procedure

  1. Append the following option to the foreman-proxy-certs-generate command that you obtain from the output of the katello-certs-check command:

    --foreman-proxy-cname loadbalancer.example.com

  2. On Foreman server, enter the foreman-proxy-certs-generate command to generate Smart Proxy certificates:

    # foreman-proxy-certs-generate \
--certs-tar /root/smart-proxy_cert/smart-proxy.tar \
--foreman-proxy-cname loadbalancer.example.com \
--foreman-proxy-fqdn smartproxy.example.com \
--server-ca-cert /root/smart-proxy_cert/ca_cert_bundle.pem \
--server-cert /root/smart-proxy_cert/smart-proxy.pem \
--server-key /root/smart-proxy_cert/smart-proxy.pem

    Retain a copy of the example foreman-installer command from the output for installing Smart Proxy server certificates.

  3. Copy the certificate archive file from Foreman server to Smart Proxy server:

    # scp /root/smartproxy.example.com-certs.tar root@smartproxy.example.com:smartproxy.example.com-certs.tar

  4. Append the following options to the foreman-installer command that you obtain from the output of the foreman-proxy-certs-generate command:

    --certs-cname "loadbalancer.example.com" \
--enable-foreman-proxy-plugin-remote-execution-script

  5. On Smart Proxy server, enter the foreman-installer command:

    # foreman-installer --scenario foreman-proxy-content \
--certs-cname "loadbalancer.example.com" \
--certs-tar-file "smartproxy.example.com-certs.tar" \
--enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-foreman-base-url "https://foreman.example.com" \
--foreman-proxy-oauth-consumer-key "oauth key" \
--foreman-proxy-oauth-consumer-secret "oauth secret" \
--foreman-proxy-register-in-foreman "true" \
--foreman-proxy-trusted-hosts "foreman.example.com" \
--foreman-proxy-trusted-hosts "smartproxy.example.com"

4.4. Configuring Smart Proxy server with custom SSL certificates for load balancing with Puppet

If you use Puppet in your Foreman configuration, then you must complete the following procedures:

  1. Configuring Smart Proxy server with custom SSL certificates to generate and sign Puppet certificates

  2. Configuring remaining Smart Proxy servers with custom SSL certificates for load balancing

4.4.1. Creating a custom SSL certificate for Smart Proxy server

This procedure outlines how to create a configuration file for the Certificate Signing Request and include the load balancer and Smart Proxy server as Subject Alternative Names (SAN). Complete this procedure on each Smart Proxy server that you want to configure for load balancing.

Procedure

  1. To store all the source certificate files, create a directory that is accessible only to the root user:

    # mkdir /root/smart-proxy_cert

  2. Create a private key with which to sign the certificate signing request (CSR).

    Note that the private key must be unencrypted. If you use a password-protected private key, remove the private key password.

    If you already have a private key for this Smart Proxy server, skip this step.

    # openssl genrsa -out /root/smart-proxy_cert/smart-proxy_cert_key.pem 4096

  3. Create the /root/smart-proxy_cert/openssl.cnf configuration file for the CSR and include the following content:

    [ req ]
req_extensions = v3_req
distinguished_name = req_distinguished_name
x509_extensions = usr_cert
prompt = no

[ req_distinguished_name ]
commonName = smartproxy.example.com (1)

[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
extendedKeyUsage = serverAuth, clientAuth, codeSigning, emailProtection
subjectAltName = @alt_names

[alt_names] (2)
DNS.1 = loadbalancer.example.com
DNS.2 = smartproxy.example.com

    1. The certificate’s common name must match the FQDN of Smart Proxy server. Ensure to change this when running the command on each Smart Proxy server that you configure for load balancing. You can also set a wildcard value *. If you set a wildcard value, you must add the -t foreman-proxy option when you use the katello-certs-check command.

    2. Under [alt_names], include the FQDN of the load balancer as DNS.1 and the FQDN of Smart Proxy server as DNS.2.

  4. Optional: If you want to add Distinguished Name (DN) details to the CSR, add the following information to the [ req_distinguished_name ] section:

    [req_distinguished_name]
CN = smartproxy.example.com
countryName =My_Country_Name (1)
stateOrProvinceName = My_State_Or_Province_Name (2)
localityName = My_Locality_Name (3)
organizationName = My_Organization_Or_Company_Name
organizationalUnitName = My_Organizational_Unit_Name (4)

    1. Two letter code

    2. Full name

    3. Full name (example: New York)

    4. Division responsible for the certificate (example: IT department)

  5. Generate CSR:

    # openssl req -new \
-key /root/smart-proxy_cert/smart-proxy_cert_key.pem \ (1)
-config /root/smart-proxy_cert/openssl.cnf \ (2)
-out /root/smart-proxy_cert/smart-proxy_cert_csr.pem (3)

    1. Path to the private key

    2. Path to the configuration file

    3. Path to the CSR to generate

  6. Send the certificate signing request to the certificate authority (CA). The same CA must sign certificates for Foreman server and Smart Proxy server.

    When you submit the request, specify the lifespan of the certificate. The method for sending the certificate request varies, so consult the CA for the preferred method. In response to the request, you can expect to receive a CA bundle and a signed certificate, in separate files.

  7. Copy the Certificate Authority bundle and Smart Proxy server certificate file that you receive from the Certificate Authority, and Smart Proxy server private key to your Foreman server.

  8. On Foreman server, validate Smart Proxy server certificate input files:

    # katello-certs-check \
-c /root/smart-proxy_cert/smart-proxy_cert.pem \ (1)
-k /root/smart-proxy_cert/smart-proxy_cert_key.pem \ (2)
-b /root/smart-proxy_cert/ca_cert_bundle.pem (3)

    1. Smart Proxy server certificate file, provided by your Certificate Authority

    2. Smart Proxy server’s private key that you used to sign the certificate

    3. Certificate Authority bundle, provided by your Certificate Authority

      If you set the commonName= to a wildcard value *, you must add the -t foreman-proxy option to the katello-certs-check command.

      Retain a copy of the example foreman-proxy-certs-generate command that is output by the katello-certs-check command for creating the Certificate Archive File for this Smart Proxy server.

4.4.2. Configuring Smart Proxy server with custom SSL certificates to generate and sign Puppet certificates

Complete this procedure only for the system where you want to configure Smart Proxy server to generate Puppet certificates for all other Smart Proxy servers that you configure for load balancing.

Procedure

  1. Append the following option to the foreman-proxy-certs-generate command that you obtain from the output of the katello-certs-check command:

    --foreman-proxy-cname loadbalancer.example.com

  2. On Foreman server, enter the foreman-proxy-certs-generate command to generate Smart Proxy certificates:

    # foreman-proxy-certs-generate \
--certs-tar /root/smart-proxy_cert/smart-proxy-ca.tar \
--foreman-proxy-cname loadbalancer.example.com \
--foreman-proxy-fqdn smart-proxy-ca.example.com \
--server-ca-cert /root/smart-proxy_cert/ca_cert_bundle.pem \
--server-cert /root/smart-proxy_cert/smart-proxy-ca.pem \
--server-key /root/smart-proxy_cert/smart-proxy-ca.pem

    Retain a copy of the example foreman-installer command from the output for installing Smart Proxy server certificates.

  3. Copy the certificate archive file from Foreman server to Smart Proxy server.

  4. Append the following options to the foreman-installer command that you obtain from the output of the foreman-proxy-certs-generate command:

    --enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-puppetca "true" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server-ca "true"

  5. On Smart Proxy server, enter the foreman-installer command:

    # foreman-installer --scenario foreman-proxy-content \
--certs-cname "loadbalancer.example.com" \
--certs-tar-file "certs.tgz" \
--enable-foreman-proxy-plugin-remote-execution-script \
--enable-puppet \
--foreman-proxy-foreman-base-url "https://foreman.example.com" \
--foreman-proxy-oauth-consumer-key "oauth key" \
--foreman-proxy-oauth-consumer-secret "oauth secret" \
--foreman-proxy-puppetca "true" \
--foreman-proxy-register-in-foreman "true" \
--foreman-proxy-trusted-hosts "foreman.example.com" \
--foreman-proxy-trusted-hosts "smart-proxy-ca.example.com" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server true \
--puppet-server-ca "true"

  6. On Smart Proxy server, generate Puppet certificates for all other Smart Proxies that you configure for load balancing, except this first system where you configure Puppet certificates signing:

    # puppet cert generate smartproxy.example.com \
--dns_alt_names=loadbalancer.example.com

    This command creates the following files on the Puppet certificate signing Smart Proxy server instance:

    • /etc/puppetlabs/puppet/ssl/certs/ca.pem

    • /etc/puppetlabs/puppet/ssl/certs/smartproxy.example.com.pem

    • /etc/puppetlabs/puppet/ssl/private_keys/smartproxy.example.com.pem

    • /etc/puppetlabs/puppet/ssl/public_keys/smartproxy.example.com.pem

4.4.3. Configuring remaining Smart Proxy servers with custom SSL certificates for load balancing

Complete this procedure for each Smart Proxy server excluding the system where you configure Smart Proxy server to sign Puppet certificates.

Procedure

  1. Append the following option to the foreman-proxy-certs-generate command that you obtain from the output of the katello-certs-check command:

    --foreman-proxy-cname loadbalancer.example.com

  2. On Foreman server, enter the foreman-proxy-certs-generate command to generate Smart Proxy certificates:

    # foreman-proxy-certs-generate \
--certs-tar /root/smart-proxy_cert/smart-proxy.tar \
--foreman-proxy-cname loadbalancer.example.com \
--foreman-proxy-fqdn smartproxy.example.com \
--server-ca-cert /root/smart-proxy_cert/ca_cert_bundle.pem \
--server-cert /root/smart-proxy_cert/smart-proxy.pem \
--server-key /root/smart-proxy_cert/smart-proxy.pem

    Retain a copy of the example foreman-installer command from the output for installing Smart Proxy server certificates.

  3. Copy the certificate archive file from Foreman server to Smart Proxy server.

    # scp /root/smartproxy.example.com-certs.tar root@smartproxy.example.com:smartproxy.example.com-certs.tar

  4. On Smart Proxy server, install the puppetserver package:

    # dnf install puppetserver

  5. On Smart Proxy server, create directories for puppet certificates:

    # mkdir -p /etc/puppetlabs/puppet/ssl/certs/ \
/etc/puppetlabs/puppet/ssl/private_keys/ \
/etc/puppetlabs/puppet/ssl/public_keys/

  6. On Smart Proxy server, copy the Puppet certificates for this Smart Proxy server from the system where you configure Smart Proxy server to sign Puppet certificates:

    # scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/certs/smartproxy.example.com.pem /etc/puppetlabs/puppet/ssl/certs/smartproxy.example.com.pem
# scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/certs/ca.pem /etc/puppetlabs/puppet/ssl/certs/ca.pem
# scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/private_keys/smartproxy.example.com.pem /etc/puppetlabs/puppet/ssl/private_keys/smartproxy.example.com.pem
# scp root@smart-proxy-ca.example.com:/etc/puppetlabs/puppet/ssl/public_keys/smartproxy.example.com.pem /etc/puppetlabs/puppet/ssl/public_keys/smartproxy.example.com.pem

  7. On Smart Proxy server, change the /etc/puppetlabs/puppet/ssl/ directory ownership to user puppet and group puppet:

    # chown -R puppet:puppet /etc/puppetlabs/puppet/ssl/

  8. On Smart Proxy server, set the SELinux context for the /etc/puppetlabs/puppet/ssl/ directory:

    # restorecon -Rv /etc/puppetlabs/puppet/ssl/

  9. Append the following options to the foreman-installer command that you obtain from the output of the foreman-proxy-certs-generate command:

    --certs-cname "loadbalancer.example.com" \
--enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-puppetca "false" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server-ca "false"

  10. On Smart Proxy server, enter the foreman-installer command:

    # foreman-installer --scenario foreman-proxy-content \
--certs-cname "loadbalancer.example.com" \
--certs-tar-file "smartproxy.example.com-certs.tar" \
--enable-foreman-proxy-plugin-remote-execution-script \
--foreman-proxy-foreman-base-url "https://foreman.example.com" \
--foreman-proxy-oauth-consumer-key "oauth key" \
--foreman-proxy-oauth-consumer-secret "oauth secret" \
--foreman-proxy-puppetca "false" \
--foreman-proxy-register-in-foreman "true" \
--foreman-proxy-trusted-hosts "foreman.example.com" \
--foreman-proxy-trusted-hosts "smartproxy.example.com" \
--puppet-ca-server "smart-proxy-ca.example.com" \
--puppet-dns-alt-names "loadbalancer.example.com" \
--puppet-server-ca "false"

5. Setting the load balancer for host registration

You can configure Foreman to register clients through a load balancer when using the host registration feature.

You will be able to register hosts to the load balancer instead of Smart Proxy. The load balancer will decide through which Smart Proxy to register the host at the time of request. Upon registration, the subscription manager on the host will be configured to manage content through the load balancer.

Prerequisites

  • You configured SSL certificates on all Smart Proxy servers. For more information, see Configuring Smart Proxy servers for load balancing.

  • You enabled Registration and Templates plugins on all Smart Proxy servers:

    # foreman-installer \
--foreman-proxy-registration true \
--foreman-proxy-templates true
Procedure

  1. On all Smart Proxy servers, set the registration and template URLs using foreman-installer:

    # foreman-installer \
--foreman-proxy-registration-url "https://loadbalancer.example.com:9090" \
--foreman-proxy-template-url "http://loadbalancer.example.com:8000"

  2. In the Foreman web UI, navigate to Infrastructure > Smart Proxies.

  3. For each Smart Proxy, click the dropdown menu in the Actions column and select Refresh.

6. Installing the load balancer

The following example provides general guidance for configuring an HAProxy load balancer using Enterprise Linux 8 server. However, you can install any suitable load balancing software solution that supports TCP forwarding.

Procedure

  1. Install HAProxy:

    # dnf install haproxy

  2. Install the following package that includes the semanage tool:

    # dnf install policycoreutils-python-utils

  3. Configure SELinux to allow HAProxy to bind any port:

    # semanage boolean --modify --on haproxy_connect_any

  4. Configure the load balancer to balance the network load for the ports as described in Ports configuration for the load balancer. For example, to configure ports for HAProxy, edit the /etc/haproxy/haproxy.cfg file to correspond with the table.

    Table 1. Ports configuration for the load balancer
    Service Port Mode Balance Mode Destination

    HTTP

    80

    TCP

    roundrobin

    port 80 on all Smart Proxy servers

    HTTPS and RHSM

    443

    TCP

    source

    port 443 on all Smart Proxy servers

    Anaconda for template retrieval

    8000

    TCP

    roundrobin

    port 8000 on all Smart Proxy servers

    Puppet (Optional)

    8140

    TCP

    roundrobin

    port 8140 on all Smart Proxy servers

    PuppetCA (Optional)

    8141

    TCP

    roundrobin

    port 8140 only on the system where you configure Smart Proxy server to sign Puppet certificates

    Smart Proxy HTTPS for Host Registration and optionally OpenSCAP

    9090

    TCP

    roundrobin

    port 9090 on all Smart Proxy servers

  5. Configure the load balancer to disable SSL offloading and allow client-side SSL certificates to pass through to back end servers. This is required because communication from clients to Smart Proxy servers depends on client-side SSL certificates.

  6. Start and enable the HAProxy service:

    # systemctl enable --now haproxy

7. Verifying the load balancing configuration

Use this procedure to verify the load balancing configuration for each Smart Proxy server.

Procedure

  1. Shut down the base operating system for your Smart Proxy server.

  2. Verify that content or subscription management features are available on clients registered to this Smart Proxy. For example, enter the subscription-manager refresh command on a client.

  3. Restart the base operating system for your Smart Proxy server.

8. Registering clients to the load balancer

To balance the load of network traffic from clients, you must register the clients to the load balancer.

You can register hosts with Foreman using the host registration feature in the Foreman web UI, Hammer CLI, or the Foreman API. For more information, see Registering Hosts in Managing hosts.

Prerequisites
Procedure

  1. In the Foreman web UI, navigate to Hosts > Register Host.

  2. From the Smart Proxy dropdown list, select the load balancer.

  3. Select Force to register a host that has been previously registered to a Smart Proxy server.

  4. From the Activation Keys list, select the activation keys to assign to your host.

  5. Click Generate to create the registration command.

  6. Click on the files icon to copy the command to your clipboard.

  7. Connect to your host using SSH and run the registration command.

  8. Ensure that the appropriate repositories have been enabled:

    • On Enterprise Linux: Check the /etc/yum.repos.d/redhat.repo file and ensure that the appropriate repositories have been enabled.

    • On Debian: Check the /etc/apt/sources.list file and ensure that the appropriate repositories have been enabled.

    • On Debian/Ubuntu: Check the /etc/apt/sources.list file and ensure that the appropriate repositories have been enabled.

    • On Enterprise Linux: Check the /etc/yum.repos.d/redhat.repo file and ensure that the appropriate repositories have been enabled.

    • On SUSE Linux Enterprise Server: Check the /etc/zypp/repos.d/ directory and ensure that the appropriate repositories have been enabled.

CLI procedure

  1. Generate the host registration command using the Hammer CLI:

    # hammer host-registration generate-command \
--activation-keys "My_Activation_Key"

    If your hosts do not trust the SSL certificate of Foreman server, you can disable SSL validation by adding the --insecure flag to the registration command.

    # hammer host-registration generate-command \
--activation-keys "My_Activation_Key" \
--insecure true

    Include the --smart-proxy-id My_Smart_Proxy_ID option. You can use the ID of any Smart Proxy server that you configured for host registration load balancing. Foreman will apply the load balancer to the registration command automatically.

    Include the --force option to register a host that has been previously registered to a Smart Proxy server.

  2. Connect to your host using SSH and run the registration command.

  3. Ensure that the appropriate repositories have been enabled:

    • On Enterprise Linux: Check the /etc/yum.repos.d/redhat.repo file and ensure that the appropriate repositories have been enabled.

    • On Debian: Check the /etc/apt/sources.list file and ensure that the appropriate repositories have been enabled.

    • On Debian/Ubuntu: Check the /etc/apt/sources.list file and ensure that the appropriate repositories have been enabled.

    • On Enterprise Linux: Check the /etc/yum.repos.d/redhat.repo file and ensure that the appropriate repositories have been enabled.

    • On SUSE Linux Enterprise Server: Check the /etc/zypp/repos.d/ directory and ensure that the appropriate repositories have been enabled.

API procedure

  1. Generate the host registration command using the Foreman API:

    # curl -X POST https://foreman.example.com/api/registration_commands \
--user "My_User_Name" \
-H 'Content-Type: application/json' \
-d '{ "registration_command": { "activation_keys": ["My_Activation_Key_1, My_Activation_Key_2"] }}'

    If your hosts do not trust the SSL certificate of Foreman server, you can disable SSL validation by adding the --insecure flag to the registration command.

    # curl -X POST https://foreman.example.com/api/registration_commands \
--user "My_User_Name" \
-H 'Content-Type: application/json' \
-d '{ "registration_command": { "activation_keys": ["My_Activation_Key_1, My_Activation_Key_2"], "insecure": true }}'

    Use an activation key to simplify specifying the environments. For more information, see Managing Activation Keys in Managing content.

    Include { "smart_proxy_id": My_Smart_Proxy_ID }. You can use the ID of any Smart Proxy server that you configured for host registration load balancing. Foreman will apply the load balancer to the registration command automatically.

    Include { "force": true } to register a host that has been previously registered to a Smart Proxy server.

    To enter a password as a command line argument, use username:password syntax. Keep in mind this can save the password in the shell history. Alternatively, you can use a temporary personal access token instead of a password. To generate a token in the Foreman web UI, navigate to My Account > Personal Access Tokens.

  2. Connect to your host using SSH and run the registration command.

  3. Ensure that the appropriate repositories have been enabled:

    • On Enterprise Linux: Check the /etc/yum.repos.d/redhat.repo file and ensure that the appropriate repositories have been enabled.

    • On Debian: Check the /etc/apt/sources.list file and ensure that the appropriate repositories have been enabled.

    • On Debian/Ubuntu: Check the /etc/apt/sources.list file and ensure that the appropriate repositories have been enabled.

    • On Enterprise Linux: Check the /etc/yum.repos.d/redhat.repo file and ensure that the appropriate repositories have been enabled.

    • On SUSE Linux Enterprise Server: Check the /etc/zypp/repos.d/ directory and ensure that the appropriate repositories have been enabled.

9. Propagating SCAP content through the load balancer

If you use OpenSCAP to manage security compliance on your clients, you must configure the SCAP client to send ARF reports to the load balancer instead of Smart Proxy. The configuration procedure depends on the method you have selected to deploy compliance policies.

9.1. Propagating SCAP content using Ansible deployment

Using this procedure, you can promote Security Content Automation Protocol (SCAP) content through the load balancer in the scope of the Ansible deployment method.

Prerequisites
Procedure

  1. In the Foreman web UI, navigate to Configure > Ansible > Variables.

  2. Search for the foreman_scap_client_port variable and click its name.

  3. In the Default Behavior area, ensure that the Override checkbox is selected.

  4. In the Parameter Type list, ensure that integer is selected.

  5. In the Default Value field, enter 9090.

  6. In the Specify Matchers area, remove all matchers that override the default value.

  7. Click Submit.

  8. Search for the foreman_scap_client_server variable and click its name.

  9. In the Default Behavior area, ensure that the Override checkbox is selected.

  10. In the Parameter Type list, ensure that string is selected.

  11. In the Default Value field, enter the FQDN of your load balancer, such as loadbalancer.example.com.

  12. In the Specify Matchers area, remove all matchers that override the default value.

  13. Click Submit.

  14. Continue with deploying a compliance policy using Ansible. For more information, see:

Verification

  • On the client, verify that the /etc/foreman_scap_client/config.yaml file contains the following lines:

    # Foreman proxy to which reports should be uploaded
:server: 'loadbalancer.example.com'
:port: 9090

9.2. Propagating SCAP content using Puppet deployment

Using this procedure, you can promote Security Content Automation Protocol (SCAP) content through the load balancer in the scope of the Puppet deployment method.

Prerequisites
Procedure

  1. In the Foreman web UI, navigate to Configure > Puppet ENC > Classes.

  2. Click foreman_scap_client.

  3. Click the Smart Class Parameter tab.

  4. In the pane to the left of the Smart Class Parameter window, click port.

  5. In the Default Behavior area, select the Override checkbox.

  6. From the Key Type list, select integer.

  7. In the Default Value field, enter 9090.

  8. In the pane to the left of the Smart Class Parameter window, click server.

  9. In the Default Behavior area, select the Override checkbox.

  10. From the Key Type list, select string.

  11. In the Default Value field, enter the FQDN of your load balancer, such as loadbalancer.example.com.

  12. In the lower left of the Smart Class Parameter window, click Submit.

  13. Continue with deploying a compliance policy using Puppet. For more information, see:

Verification

  • On the client, verify that the /etc/foreman_scap_client/config.yaml file contains the following lines:

    # Foreman proxy to which reports should be uploaded
:server: 'loadbalancer.example.com'
:port: 9090