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

The graphics in this section are Red Hat illustrations. Non-Red Hat illustrations are welcome. If you want to contribute alternative images, raise a pull request in the Foreman Documentation GitHub page. Note that in Red Hat terminology, "Satellite" refers to Foreman and "Capsule" refers to Smart Proxy.

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. Load balancer works with the following services and features:

  • Registration using subscription-manager

  • Content Management with yum repositories

  • Optional: Puppet

Note
Provisioning hosts is not supported in the Foreman load-balanced setup.
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 Smart Proxy server. Foreman does not support configuring existing Smart Proxy servers for load balancing.

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 the 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, for example:

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

    Retain a copy of the example foreman-installer command that is output by the foreman-proxy-certs-generate command for installing the 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: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. Set the --puppet-ca-server option to point to the Smart Proxy server where you enter the command. You must install Puppet CA on your Smart Proxy servers, regardless of whether you intend to use it or not. Puppet is configured in its default single-node configuration.

    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smartproxy.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  4. On Smart Proxy server, enter the foreman-installer command, for example:

    # foreman-installer --no-enable-foreman \
    --foreman-proxy-content-parent-fqdn        "foreman.example.com" \
    --foreman-proxy-register-in-foreman        "true" \
    --foreman-proxy-foreman-base-url           "https://foreman.example.com" \
    --foreman-proxy-trusted-hosts              "foreman.example.com" \
    --foreman-proxy-trusted-hosts              "smartproxy.example.com" \
    --foreman-proxy-oauth-consumer-key         "oauth key" \
    --foreman-proxy-oauth-consumer-secret      "oauth secret" \
    --certs-tar-file                           "smartproxy.example.com-certs.tar" \
    --puppet-server-foreman-url                "https://foreman.example.com" \
    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smartproxy.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh

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:

Configuring Smart Proxy server 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. In the examples in this procedure, the FQDN of this Smart Proxy server is smart-proxy_ca.example.com.

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

    Retain a copy of the example foreman-installer command that is output by the foreman-proxy-certs-generate command for installing the 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" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  4. On Smart Proxy server, enter the foreman-installer command, for example:

    # foreman-installer --no-enable-foreman \
    --foreman-proxy-content-parent-fqdn        "foreman.example.com" \
    --foreman-proxy-register-in-foreman        "true" \
    --foreman-proxy-foreman-base-url           "https://foreman.example.com" \
    --foreman-proxy-trusted-hosts              "foreman.example.com" \
    --foreman-proxy-trusted-hosts              "smart-proxy_ca.example.com" \
    --foreman-proxy-oauth-consumer-key         "oauth key" \
    --foreman-proxy-oauth-consumer-secret      "oauth secret" \
    --certs-tar-file          "smart-proxy_ca.example.com-certs.tar" \
    --puppet-server-foreman-url                "https://foreman.example.com" \
    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  5. On Smart Proxy server, generate Puppet certificates for all other Smart Proxy servers 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 system where you configure Smart Proxy server to sign Puppet certificates:

    • /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

Configuring Remaining Smart Proxy servers for Load Balancing

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

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

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

    Retain a copy of the example foreman-installer command that is output by the foreman-proxy-certs-generate command for installing the 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:smartproxy.example.com-certs.tar
  3. On Smart Proxy server, install the puppetserver package:

    # yum 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/ca.pem \
    /etc/puppetlabs/puppet/ssl/certs/ca.pem
    # 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/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 directory ownership to user puppet, group puppet and set the SELinux contexts:

    # chown -R puppet:puppet /etc/puppetlabs/puppet/ssl/
    # restorecon -Rv /etc/puppetlabs/puppet/ssl/
  7. 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" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "false" \
    --puppet-server-ca                         "false" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  8. On Smart Proxy server, enter the foreman-installer command, for example:

    # foreman-installer --no-enable-foreman \
    --foreman-proxy-content-parent-fqdn        "foreman.example.com" \
    --foreman-proxy-register-in-foreman        "true" \
    --foreman-proxy-foreman-base-url           "https://foreman.example.com" \
    --foreman-proxy-trusted-hosts              "foreman.example.com" \
    --foreman-proxy-trusted-hosts              "smartproxy.example.com" \
    --foreman-proxy-oauth-consumer-key         "oauth key" \
    --foreman-proxy-oauth-consumer-secret      "oauth secret" \
    --certs-tar-file                           "smartproxy.example.com-certs.tar" \
    --puppet-server-foreman-url                "https://foreman.example.com" \
    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "false" \
    --puppet-server-ca                         :false" \
    --enable-foreman-proxy-plugin-remote-execution-ssh

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 Custom SSL Certificates 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. On Smart Proxy server, create a directory to contain all the source certificate files, accessible to only the root user:

    # mkdir /root/smart-proxy_cert
    # cd /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 certificate request configuration file with the following content:

    [ req ]
    default_bits       = 4096
    distinguished_name = req_distinguished_name
    req_extensions     = req_ext
    prompt = no
    
    [ req_distinguished_name ]
    countryName=2 Letter Country Code
    stateOrProvinceName=State or Province Full Name
    localityName=Locality Name
    0.organizationName=Organization Name
    organizationalUnitName=Smart Proxy Organization Unit Name
    commonName=smartproxy.example.com  (1)
    emailAddress=Email Address
    
    [ req_ext ]
    #authorityKeyIdentifier=keyid,issuer
    #basicConstraints=CA:FALSE
    keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
    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. Create a Certificate Signing Request (CSR) for the SAN certificate.

    # openssl req -new \
    -key /root/smart-proxy_cert/smart-proxy_cert_key.pem \ (1)
    -config SAN_config.cfg \                   (2)
    -out /root/smart-proxy_cert/smart-proxy_cert_csr.pem   (3)
    1. Smart Proxy server’s private key, used to sign the certificate

    2. The certificate request configuration file

    3. Certificate Signing Request file

  5. Send the certificate request to the Certificate Authority:

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

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

  7. On Foreman server, validate the 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

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. For example:

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

    Retain a copy of the example foreman-installer command from the output for installing the 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. Set the --puppet-ca-server option to point to the Smart Proxy server where you enter the command. You must install Puppet CA on your Smart Proxy servers, regardless of whether you intend to use it or not. Puppet is configured in its default single-node configuration.

    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smartproxy.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  5. On Smart Proxy server, enter the foreman-installer command, for example:

    # foreman-installer --no-enable-foreman \
    --foreman-proxy-content-parent-fqdn        "foreman.example.com" \
    --foreman-proxy-register-in-foreman        "true" \
    --foreman-proxy-foreman-base-url           "https://foreman.example.com" \
    --foreman-proxy-trusted-hosts              "foreman.example.com" \
    --foreman-proxy-trusted-hosts              "smartproxy.example.com" \
    --foreman-proxy-oauth-consumer-key         "oauth key" \
    --foreman-proxy-oauth-consumer-secret      "oauth secret" \
    --certs-tar-file                           "smartproxy.example.com-certs.tar" \
    --puppet-server-foreman-url                "https://foreman.example.com" \
    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smartproxy.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh

4.4. Configuring Smart Proxy server with Custom SSL Certificates for Load Balancing with Puppet

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

4.4.1. Creating Custom SSL Certificates 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. On Smart Proxy server, create a directory to contain all the source certificate files, accessible to only the root user:

    # mkdir /root/smart-proxy_cert
    # cd /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.pem 4096
  3. Create the certificate request configuration file with the following content:

    [ req ]
    default_bits       = 4096
    distinguished_name = req_distinguished_name
    req_extensions     = req_ext
    prompt = no
    
    [ req_distinguished_name ]
    countryName=2 Letter Country Code
    stateOrProvinceName=State or Province Full Name
    localityName=Locality Name
    0.organizationName=Organization Name
    organizationalUnitName=Smart Proxy Organization Unit Name
    commonName=smartproxy.example.com  (1)
    emailAddress=Email Address
    
    [ req_ext ]
    #authorityKeyIdentifier=keyid,issuer
    #basicConstraints=CA:FALSE
    keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
    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. 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. Create a Certificate Signing Request (CSR) for the SAN certificate:

    # openssl req -new \
    -key /root/smart-proxy_cert/smart-proxy.pem \ (1)
    -config SAN_config.cfg \          (2)
    -out /root/smart-proxy_cert/smart-proxy.pem   (3)
    1. Smart Proxy server’s private key, used to sign the certificate

    2. The certificate request configuration file

    3. Certificate Signing Request file

  5. Send the certificate request to the Certificate Authority:

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

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

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

    # katello-certs-check \
    -c /root/smart-proxy_cert/smart-proxy.pem \      (1)
    -k /root/smart-proxy_cert/smart-proxy.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 for Load Balancing with Puppet

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

Configuring Smart Proxy server 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. In the examples in this procedure, the FQDN of this Smart Proxy server is smart-proxy_ca.example.com.

  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. For example:

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

    Retain a copy of the example foreman-installer command from the output for installing the 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:

    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  5. On Smart Proxy server, enter the foreman-installer command, for example:

    foreman-installer --no-enable-foreman \
    --foreman-proxy-content-parent-fqdn        "foreman.example.com" \
    --foreman-proxy-register-in-foreman        "true" \
    --foreman-proxy-foreman-base-url           "https://foreman.example.com" \
    --foreman-proxy-trusted-hosts              "foreman.example.com" \
    --foreman-proxy-trusted-hosts              "smart-proxy_ca.example.com" \
    --foreman-proxy-oauth-consumer-key         "oauth key" \
    --foreman-proxy-oauth-consumer-secret      "oauth secret" \
    --certs-tar-file                           "certs.tgz" \
    --puppet-server-foreman-url                "https://foreman.example.com" \
    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "true" \
    --puppet-server-ca                         "true" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  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

Configuring Remaining Smart Proxy servers for Load Balancing

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

  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. For example:

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

    Retain a copy of the example foreman-installer command from the output for installing the 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:

    # yum 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/ca.pem \
    /etc/puppetlabs/puppet/ssl/certs/ca.pem
    # 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/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 directory ownership to user puppet, group puppet and set the SELinux contexts:

    # chown -R puppet:puppet /etc/puppetlabs/puppet/ssl/
    # 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" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "false" \
    --puppet-server-ca                         "false" \
    --enable-foreman-proxy-plugin-remote-execution-ssh
  9. On Smart Proxy server, enter the foreman-installer command, for example:

    # foreman-installer --no-enable-foreman \
    --foreman-proxy-content-parent-fqdn        "foreman.example.com" \
    --foreman-proxy-register-in-foreman        "true" \
    --foreman-proxy-foreman-base-url           "https://foreman.example.com" \
    --foreman-proxy-trusted-hosts              "foreman.example.com" \
    --foreman-proxy-trusted-hosts              "smartproxy.example.com" \
    --foreman-proxy-oauth-consumer-key         "oauth key" \
    --foreman-proxy-oauth-consumer-secret      "oauth secret" \
    --certs-tar-file                           "smartproxy.example.com-certs.tar" \
    --puppet-server-foreman-url                "https://foreman.example.com" \
    --certs-cname                              "loadbalancer.example.com" \
    --puppet-dns-alt-names                     "loadbalancer.example.com" \
    --puppet-ca-server                         "smart-proxy_ca.example.com" \
    --foreman-proxy-puppetca                   "false" \
    --puppet-server-ca                         "false" \
    --enable-foreman-proxy-plugin-remote-execution-ssh

5. Installing the Load Balancer

The following example provides general guidance for configuring an HAProxy load balancer on a Red Hat Enterprise Linux server. However, you can install any suitable load balancing software solution that supports TCP forwarding and sticky sessions.

  1. On a Red Hat Enterprise Linux 7 host, install HAProxy:

    # yum install haproxy
  2. Install the following package that includes the semanage tool:

    # yum install policycoreutils-python
  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.

    You must configure sticky session on TCP port 443 to request yum metadata for RPM repositories from different Smart Proxy servers that you configure for load balancing.

    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

    443

    TCP

    source

    port 443 on all Smart Proxy servers

    RHSM

    8443

    TCP

    roundrobin

    port 8443 on all Smart Proxy servers

    AMQP

    5647

    TCP

    roundrobin

    port 5647 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

    SmartProxy (Optional for OpenScap)

    9090

    TCP

    roundrobin

    port 9090 on all Smart Proxy servers

    Docker (Optional)

    5000

    TCP

    roundrobin

    port 5000 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 start haproxy
    # systemctl enable haproxy

6. Registering Clients

You can register a client running a Red Hat Enterprise Linux version 6, 7 or 8 operating system to Smart Proxy servers that you configure for load balancing. For more information about registering clients and configuring them to use Puppet, see Registering Hosts in the Managing Hosts guide.

To register clients, proceed to one of the following procedures:

6.1. Registering Clients Using the Bootstrap Script

To register clients, enter the following command on the client. You must complete the registration procedure for each client.

Prerequisite

Ensure that you install the bootstrap script on the client and change the script’s file permissions to executable. For more information, see Registering Hosts to Foreman Using The Bootstrap Script in the Managing Hosts guide.

  • On Red Hat Enterprise Linux 8, enter the following command:

    # /usr/libexec/platform-python bootstrap.py \
    --login=admin \
    --server loadbalancer.example.com \
    --organization="Your_Organization" \
    --location="Your_Location" \
    --hostgroup="Your_Hostgroup" \
    --activationkey=your_activation_key \
    --enablerepos=https://yum.theforeman.org/client/2.0/el7/x86_64/foreman-client-release.rpm \
    --puppet-ca-port 8141 \    (1)
    --force                    (2)
    1. Include the --puppet-ca-port 8141 option if you use Puppet.

    2. Include the --force option to register the client that has been previously registered to a standalone Smart Proxy.

  • On Red Hat Enterprise Linux 7, 6, or 5, enter the following command:

    # python bootstrap.py --login=admin \
    --server loadbalancer.example.com \
    --organization="Your_Organization" \
    --location="Your_Location" \
    --hostgroup="Your_Hostgroup" \
    --activationkey=your_activation_key \
    --enablerepos=https://yum.theforeman.org/client/2.0/el7/x86_64/foreman-client-release.rpm \
    --puppet-ca-port 8141 \    (1)
    --force                    (2)
    1. Include the --puppet-ca-port 8141 option if you use Puppet.

    2. Include the --force option to register the client that has been previously registered to a standalone Smart Proxy.

The script prompts for the password corresponding to the Foreman user name you entered with the --login option.

6.2. Registering Clients Manually

To register clients manually, complete the following procedure on each client that you register.

Procedure
  1. Remove the katello-ca-consumer package if it is installed:

    # yum remove 'katello-ca-consumer*'
  2. Install the katello-ca-consumer package from the load balancer:

    # rpm -Uvh \
    http://loadbalancer.example.com/pub/katello-ca-consumer-latest.noarch.rpm
  3. Register the client and include the --serverurl and --baseurl options:

    # subscription-manager register --org=Your_Organization \
    --activationkey=Your_Activation_Key \
    --serverurl=https://loadbalancer.example.com:8443/rhsm \
    --baseurl=https://loadbalancer.example.com/pulp/repos

7. Promoting SCAP Content to Clients

The following section describes how to promote Security Content Automation Protocol (SCAP) content to clients registered to Smart Proxy servers that you configure for load balancing.

Prerequisites
  • Ensure that you configure the SCAP content. For more information, see Configuring SCAP Content in Administering Foreman.

Procedure
  1. In the Foreman web UI, navigate to Configure > Classes and click foreman_scap_client.

  2. Click the Smart Class Parameter tab.

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

  4. In the Default Behavior area, select the Override check box.

  5. From the Key Type list, select integer.

  6. In the Default Value field, enter 9090.

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

  8. In the Default Behavior area, select the Override check box.

  9. From the Key Type list, select string.

  10. In the Default Value field, enter the FQDN of your load balancer. For example, loadbalancer.example.com.

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

  12. Add the puppet module that contains the foreman_scap_client puppet class to a Content View. Publish and promote this Content View to your client’s environment.

  13. If you want to verify the configuration, run the Puppet agent on the client to promote the changes. Do not run the Puppet agent on every client manually because the Puppet agent runs on the clients every 30 minutes.

    # puppet agent -t --noop
  14. 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
Additional Resources

8. Verifying the Load Balancing Configuration

You can verify the load balancing configuration by completing the following steps for each Smart Proxy server that you configure:

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

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

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