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6.5. Managing Server Roles

Based on the services installed on an IdM server, it can perform various server roles. For example: CA server, DNS server, or key recovery authority (KRA) server.

6.5.1. Viewing Server Roles

Web UI: Viewing Server Roles

For a complete list of the supported server roles, see IPA Server → Topology → Server Roles.
  • Role status absent means that no server in the topology is performing the role.
  • Role status enabled means that one or more servers in the topology are performing the role.

Figure 6.14. Server Roles in the Web UI

Server Roles in the Web UI

Command Line: Viewing Server Roles

The ipa config-show command displays all CA servers, NTP servers, and the current CA renewal master: 
$ ipa config-show
  ...
  IPA masters: server1.example.com, server2.example.com, server3.example.com
  IPA CA servers: server1.example.com, server2.example.com
  IPA NTP servers: server1.example.com, server2.example.com, server3.example.com
  IPA CA renewal master: server1.example.com
The ipa server-show command displays a list of roles enabled on a particular server. For example, for a list of roles enabled on server.example.com: 
$ ipa server-show
Server name: server.example.com
  ...
  Enabled server roles: CA server, DNS server, NTP server, KRA server
The ipa server-find --servrole searches for all servers with a particular server role enabled. For example, to search for all CA servers: 
$ ipa server-find --servrole "CA server"
---------------------
2 IPA servers matched
---------------------
  Server name: server1.example.com
  ...

  Server name: server2.example.com
  ...
----------------------------
Number of entries returned 2
----------------------------

6.5.2. Promoting a Replica to a Master CA Server

Note
This section describes changing the CA renewal master at domain level 1 (see Chapter 7, Displaying and Raising the Domain Level). For documentation on changing the CA renewal master at domain level 0, see Section D.4, “Promoting a Replica to a Master CA Server”.
If your IdM deployment uses an embedded certificate authority (CA), one of the IdM CA servers acts as the master CA: it manages the renewal of CA subsystem certificates and generates certificate revocation lists (CRLs). By default, the master CA is the first server on which the system administrator installed the CA role using the ipa-server-install or ipa-ca-install command.
If you plan to take the master CA server offline or decommission it, promote another CA server to take the its place as the new CA renewal master:
  1. Configure the replica to handle CA subsystem certificate renewal.
  2. Configure the replica to generate CRLs. See Section 6.5.2.2, “Changing Which Server Generates CRLs”.
  3. Before decommissioning the previous master CA server, make sure the new master works properly. See Section 6.5.2.3, “Verifying That the New Master CA Server Is Configured Correctly”.

6.5.2.1. Changing the Current CA Renewal Master

Web UI: Changing the Current CA Renewal Master

  1. Select IPA Server → Configuration.
  2. In the IPA CA renewal master field, select the new CA renewal master.

Command Line: Changing the Current CA Renewal Master

Use the ipa config-mod --ca-renewal-master-server command: 
$ ipa config-mod --ca-renewal-master-server new_ca_renewal_master.example.com
  ...
  IPA masters: old_ca_renewal_master.example.com, new_ca_renewal_master.example.com
  IPA CA servers: old_ca_renewal_master.example.com, new_ca_renewal_master.example.com
  IPA NTP servers: old_ca_renewal_master.example.com, new_ca_renewal_master.example.com
  IPA CA renewal master: new_ca_renewal_master.example.com
The output confirms that the update was successful.

6.5.2.2. Changing Which Server Generates CRLs

To change which server generates certificate revocation lists (CRL):
  1. If you do not know the current CRL generation master, use the ipa-crlgen-manage status command on each IdM certificate authority (CA) to determine whether CRL generation is enabled: 
    # ipa-crlgen-manage status
CRL generation: enabled
  2. On the current CRL generation master, disable the feature: 
    # ipa-crlgen-manage disable
  3. On the other CA host that you want to configure as the new CRL generation master, enable the feature: 
    # ipa-crlgen-manage enable

6.5.2.3. Verifying That the New Master CA Server Is Configured Correctly

Make sure the /var/lib/ipa/pki-ca/publish/MasterCRL.bin file exists on the new master CA server.
The file is generated based on the time interval defined in the /etc/pki/pki-tomcat/ca/CS.cfg file using the ca.crl.MasterCRL.autoUpdateInterval parameter. The default value is 240 minutes (4 hours).
Note
If you update the ca.crl.MasterCRL.autoUpdateInterval parameter, the change will become effective after the next already scheduled CRL update.
If the file exists, the new master CA server is configured correctly, and you can safely dismiss the previous CA master system.

6.5.3. Demotion and Promotion of Hidden Replicas

After a replica has been installed, you can change whether the replica is hidden or visible:
  • To demote a visible replica to a hidden replica:
    1. If the replica is a CA renewal master, move the service to another replica. For details, see Section 6.5.2.1, “Changing the Current CA Renewal Master”.
    2. Change the state of the replica to hidden: 
      # ipa server-state replica.idm.example.com --state=hidden
  • To promote a hidden replica to a visible replica, enter: 
    # ipa server-state replica.idm.example.com --state=enabled
Note
The hidden replica feature is available in Red Hat Enterprise Linux 7.7 and later as a Technology Preview and, therefore, not supported.