Chapter 1. Migrating your IdM environment from RHEL 7 servers to RHEL 8 servers

To upgrade a RHEL 7 IdM environment to RHEL 8, you must first add new RHEL 8 IdM replicas to your RHEL 7 IdM environment, and then retire the RHEL 7 servers.

Warning
  • Performing an in-place upgrade of RHEL 7 IdM servers to RHEL 8 is not supported.
  • Migrating directly to RHEL 8 from RHEL 6 or earlier versions is not supported. To properly update your IdM data, you must perform incremental migrations.

    For example, to migrate a RHEL 6 IdM environment to RHEL 8:

    1. Migrate from RHEL 6 servers to RHEL 7 servers. See Migrating Identity Management from Red Hat Enterprise Linux 6 to Version 7.
    2. Migrate from RHEL 7 servers to RHEL 8 servers, as described in this section.

This section describes how to migrate all Identity Management (IdM) data and configuration from a Red Hat Enterprise Linux (RHEL) 7 server to a RHEL 8 server. You can also use this procedure to migrate from FreeIPA servers on non-RHEL Linux distributions to IdM on RHEL 8 servers.

The migration procedure includes:

  1. Configuring a RHEL 8 IdM server and adding it as a replica to your current RHEL 7 IdM environment. For details, see Installing the RHEL 8 Replica.
  2. Making the RHEL 8 server the certificate authority (CA) renewal server. For details, see Assigning the CA renewal server role to the RHEL 8 IdM server.
  3. Stopping the generation of the certificate revocation list (CRL) on the RHEL 7 server and redirecting CRL requests to RHEL 8. For details, see Stopping CRL generation on a RHEL 7 IdM CA server.
  4. Starting the generation of the CRL on the RHEL 8 server. For details, see Starting CRL generation on the new RHEL 8 IdM CA server.
  5. Stopping and decommissioning the original RHEL 7 CA renewal server. For details, see Stopping and decommissioning the RHEL 7 server.

In the following procedures:

  • rhel8.example.com is the RHEL 8 system that will become the new CA renewal server.
  • rhel7.example.com is the original RHEL 7 CA renewal server. To identify which Red Hat Enterprise Linux 7 server is the CA renewal server, run the following command on any IdM server:

    [root@rhel7 ~]# ipa config-show | grep "CA renewal"
    IPA CA renewal master: rhel7.example.com

    If your IdM deployment does not use a certificate authority (CA), any IdM server running on RHEL 7 can be rhel7.example.com.

1.1. Prerequisites for migrating IdM from RHEL 7 to 8

On rhel7.example.com:

  1. Upgrade the system to the latest RHEL 7 version.
  2. Ensure that the domain level for your domain is set to 1. For more information, see Displaying and Raising the Domain Level in the Linux Domain Identity, Authentication, and Policy Guide for RHEL 7.
  3. Update the ipa-* packages to their latest version:

    [root@rhel7 ~]# yum update ipa-*
    Warning

    When upgrading multiple Identity Management (IdM) servers, wait at least 10 minutes between each upgrade.

    When two or more servers are upgraded simultaneously or with only short intervals between the upgrades, there is not enough time to replicate the post-upgrade data changes throughout the topology, which can result in conflicting replication events.

On rhel8.example.com:

  1. The latest version of Red Hat Enterprise Linux is installed on the system. For more information, see Performing a standard RHEL 8 installation.
  2. Ensure you know the time server rhel7.example.com is synchronized with:

    [root@rhel7 ~]# ntpstat
    synchronised to NTP server (ntp.example.com) at stratum 3
       time correct to within 42 ms
       polling server every 1024 s
    Important

    In RHEL 8, IdM does not provide its own time server: the installation of IdM on rhel8.example.com does not result in the installation of an NTP server on the host. Therefore, you need to use a separate NTP server, for example ntp.example.com. For more information, see Migrating to chrony and Time service requirements for IdM.

    While rhel7.example.com can be used in an NTP server role, you will decommission the server as part of the migration process. Therefore, rhel8.example.com needs to be synchronized directly with ntp.example.com instead. You can specify this during the client installation process.

  3. Ensure the system is an IdM client enrolled into the domain for which rhel7.example.com IdM server is authoritative. For more information, see Installing an IdM client.

    Important

    When installing the client, specify the time server from the previous step using the --ntp-server option. If you are using a pool of NTP servers, use the --ntp-pool option.

    If you do not specify an NTP server manually, it will be automatically set from DNS records. This can lead to rhel8.example.com synchronizing with rhel7.example.com. This will cause issues when the RHEL 7 server is decommissioned.

    If the RHEL8 system is already properly configured as an NTP client, you can use the --no-ntp option when performing the IdM client installation.

  4. Ensure the system meets the requirements for IdM server installation. See Preparing the system for IdM server installation.
  5. Ensure the system is authorized for the installation of an IdM replica. See Authorizing the installation of a replica on an IdM client.
  6. Update the ipa-* packages to their latest version:

    [root@rhel7 ~]# yum update ipa-*

1.2. Installing the RHEL 8 replica

  1. List which server roles are present in your RHEL 7 environment:

    [root@rhel7 ~]# ipa server-role-find --status enabled --server rhel7.example.com
    ----------------------
    3 server roles matched
    ----------------------
      Server name: rhel7.example.com
      Role name: CA server
      Role status: enabled
    
      Server name: rhel7.example.com
      Role name: DNS server
      Role status: enabled
    
      Server name: rhel7.example.com
      Role name: NTP server
      Role status: enabled
    [... output truncated ...]
  2. [Optional] If you want to use the same per-server forwarders for rhel8.example.com that rhel7.example.com is using, view the per-server forwarders for rhel7.example.com:

    [root@rhel7 ~]# ipa dnsserver-show rhel7.example.com
    -----------------------------
    1 DNS server matched
    -----------------------------
      Server name: rhel7.example.com
      SOA mname: rhel7.example.com.
      Forwarders: 192.0.2.20
      Forward policy: only
    --------------------------------------------------
    Number of entries returned 1
    --------------------------------------------------
  3. Install the IdM server on rhel8.example.com as a replica of the IdM RHEL 7 server, including all the server roles present on your rhel7.example.com except the NTP server role. To install the roles from the example above, use these options with the ipa-replica-install command:

    • --setup-ca to set up the Certificate System component
    • --setup-dns and --forwarder to configure an integrated DNS server and set a per-server forwarder to take care of DNS queries that go outside the IdM domain

      Note

      Additionally, if your IdM deployment is in a trust relationship with Active Directory (AD), add the --setup-adtrust option to the ipa-replica-install command to configure AD trust capability on rhel8.example.com.

      To set up an IdM server with the IP address of 192.0.2.1 that uses a per-server forwarder with the IP address of 192.0.2.20:

      [root@rhel8 ~]# ipa-replica-install --setup-ca --ip-address 192.0.2.1 --setup-dns --forwarder 192.0.2.20

      You do not need to specify the RHEL 7 IdM server itself because if DNS is working correctly, rhel8.example.com will find it using DNS autodiscovery.

  4. [Optional] Add an _ntp._udp service (SRV) record for your external NTP time server to the DNS of the newly-installed IdM server, rhel8.example.com. Doing this is recommended because IdM in RHEL 8 does not provide its own time service. The presence of the SRV record for the time server in IdM DNS ensures that future RHEL 8 replica and client installations are automatically configured to synchronize with the time server used by rhel8.example.com. This is because ipa-client-install looks for the _ntp._udp DNS entry unless --ntp-server or --ntp-pool options are provided on the install command-line interface (CLI).

Verification

  1. Verify that the IdM services are running on rhel8.example.com:

    [root@rhel8 ~]# ipactl status
    Directory Service: RUNNING
    [... output truncated ...]
    ipa: INFO: The ipactl command was successful
  2. Verify that server roles for rhel8.example.com are the same as for rhel7.example.com except the NTP server role:

    [root@rhel8 ~]$ kinit admin
    [root@rhel8 ~]$ ipa server-role-find --status enabled --server rhel8.example.com
    ----------------------
    2 server roles matched
    ----------------------
      Server name: rhel8.example.com
      Role name: CA server
      Role status: enabled
    
      Server name: rhel8.example.com
      Role name: DNS server
      Role status: enabled
  3. [Optional] Display details about the replication agreement between rhel7.example.com and rhel8.example.com:

    [root@rhel8 ~]# ipa-csreplica-manage list --verbose rhel8.example.com
    Directory Manager password:
    
    rhel7.example.com
    last init status: None
    last init ended: 1970-01-01 00:00:00+00:00
    last update status: Error (0) Replica acquired successfully: Incremental update succeeded
    last update ended: 2019-02-13 13:55:13+00:00
  4. [Optional] If your IdM deployment is in a trust relationship with AD, verify that it is working:

    1. link: Verify the Kerberos configuration
    2. Attempt to resolve an AD user on rhel8.example.com:

      [root@rhel8 ~]# id aduser@ad.domain
  5. Verify that rhel8.example.com is synchronized with the NTP server:

    [root@rhel8 ~]# chronyc tracking
    Reference ID    : CB00710F (ntp.example.com)
    Stratum         : 3
    Ref time (UTC)  : Tue Nov 16 09:49:17 2021
    [... output truncated ...]

1.3. Assigning the CA renewal server role to the RHEL 8 IdM server

Note

Complete the steps in this section only if your IdM deployment uses an embedded certificate authority (CA).

On rhel8.example.com, configure rhel8.example.com as the new CA renewal server:

  1. Configure rhel8.example.com to handle CA subsystem certificate renewal:

    [root@rhel8 ~]# ipa config-mod --ca-renewal-master-server rhel8.example.com
      ...
      IPA masters: rhel7.example.com, rhel8.example.com
      IPA CA servers: rhel7.example.com, rhel8.example.com
      IPA NTP servers: rhel7.example.com, rhel8.example.com
      IPA CA renewal master: rhel8.example.com

    The output confirms that the update was successful.

  2. On rhel8.example.com, enable the certificate updater task:

    1. Open the /etc/pki/pki-tomcat/ca/CS.cfg configuration file for editing.
    2. Remove the ca.certStatusUpdateInterval entry, or set it to the desired interval in seconds. The default value is 600.
    3. Save and close the /etc/pki/pki-tomcat/ca/CS.cfg configuration file.
    4. Restart IdM services:

      [user@rhel8 ~]$ ipactl restart
  3. On rhel7.example.com, disable the certificate updater task:

    1. Open the /etc/pki/pki-tomcat/ca/CS.cfg configuration file for editing.
    2. Change ca.certStatusUpdateInterval to 0, or add the following entry if it does not exist:

      ca.certStatusUpdateInterval=0
    3. Save and close the /etc/pki/pki-tomcat/ca/CS.cfg configuration file.
    4. Restart IdM services:

      [user@rhel7 ~]$ ipactl restart

1.4. Stopping CRL generation on a RHEL 7 IdM CA server

Note

Complete the steps in this section only if your IdM deployment uses an embedded certificate authority (CA).

This section describes how to stop generating the Certificate Revocation List (CRL) on the rhel7.example.com CA server using the ipa-crlgen-manage command.

Prerequisites

  • You must be logged in as root.

Procedure

  1. Optionally, check if rhel7.example.com is generating the CRL:

    [root@rhel7 ~]# ipa-crlgen-manage status
    CRL generation: enabled
    Last CRL update: 2019-10-31 12:00:00
    Last CRL Number: 6
    The ipa-crlgen-manage command was successful
  2. Stop generating the CRL on the rhel7.example.com server:

    [root@rhel7 ~]# ipa-crlgen-manage disable
    Stopping pki-tomcatd
    Editing /var/lib/pki/pki-tomcat/conf/ca/CS.cfg
    Starting pki-tomcatd
    Editing /etc/httpd/conf.d/ipa-pki-proxy.conf
    Restarting httpd
    CRL generation disabled on the local host. Please make sure to configure CRL generation on another master with ipa-crlgen-manage enable.
    The ipa-crlgen-manage command was successful
  3. Optionally, check if the rhel7.example.com server stopped generating the CRL:

    [root@rhel7 ~]# ipa-crlgen-manage status

The rhel7.example.com server stopped generating the CRL. The next step is to enable generating the CRL on rhel8.example.com.

1.5. Starting CRL generation on the new RHEL 8 IdM CA server

Note

Complete the steps in this section only if your IdM deployment uses an embedded certificate authority (CA).

Prerequisites

  • You must be logged in as root on the rhel8.example.com machine.

Procedure

  1. To start generating CRL on rhel8.example.com, use the ipa-crlgen-manage enable command:

    [root@rhel8 ~]# ipa-crlgen-manage enable
    Stopping pki-tomcatd
    Editing /var/lib/pki/pki-tomcat/conf/ca/CS.cfg
    Starting pki-tomcatd
    Editing /etc/httpd/conf.d/ipa-pki-proxy.conf
    Restarting httpd
    Forcing CRL update
    CRL generation enabled on the local host. Please make sure to have only a single CRL generation master.
    The ipa-crlgen-manage command was successful
  2. To check if CRL generation is enabled, use the ipa-crlgen-manage status command:

    [root@rhel8 ~]# ipa-crlgen-manage status
    CRL generation: enabled
    Last CRL update: 2019-10-31 12:10:00
    Last CRL Number: 7
    The ipa-crlgen-manage command was successful

1.6. Stopping and decommissioning the RHEL 7 server

  1. Ensure that all data, including the latest changes, have been correctly migrated from rhel7.example.com to rhel8.example.com. For example:

    1. Add a new user on rhel7.example.com:

      [root@rhel7 ~]# ipa user-add random_user
      First name: random
      Last name: user
    2. Check that the user has been replicated to rhel8.example.com:

      [root@rhel8 ~]# ipa user-find random_user
      --------------
      1 user matched
      --------------
        User login: random_user
        First name: random
        Last name: user
  2. Ensure that a Distributed Numeric Assignment (DNA) ID range is allocated to rhel8.example.com. Use one of the following methods:

    • Activate the DNA plug-in on rhel8.example.com directly by creating another test user:

      [root@rhel8 ~]# ipa user-add another_random_user
      First name: another
      Last name: random_user
    • Assign a specific DNA ID range to rhel8.example.com:

      1. On rhel7.example.com, display the IdM ID range:

        [root@rhel7 ~]# ipa idrange-find
        ----------------
        3 ranges matched
        ----------------
          Range name: EXAMPLE.COM_id_range
          First Posix ID of the range: 196600000
          Number of IDs in the range: 200000
          First RID of the corresponding RID range: 1000
          First RID of the secondary RID range: 100000000
          Range type: local domain range
      2. On rhel7.example.com, display the allocated DNA ID ranges:

        [root@rhel7 ~]# ipa-replica-manage dnarange-show
        rhel7.example.com: 196600026-196799999
        rhel8.example.com: No range set
      3. Reduce the DNA ID range allocated to rhel7.example.com so that a section becomes available to rhel8.example.com:

        [root@rhel7 ~]# ipa-replica-manage dnarange-set rhel7.example.com 196600026-196699999
      4. Assign the remaining part of the IdM ID range to rhel8.example.com:

        [root@rhel7 ~]# ipa-replica-manage dnarange-set rhel8.example.com 196700000-196799999
  3. Stop all IdM services on rhel7.example.com to force domain discovery to the new rhel8.example.com server.

    [root@rhel7 ~]# ipactl stop
    Stopping CA Service
    Stopping pki-ca:                                           [  OK  ]
    Stopping HTTP Service
    Stopping httpd:                                            [  OK  ]
    Stopping MEMCACHE Service
    Stopping ipa_memcached:                                    [  OK  ]
    Stopping DNS Service
    Stopping named: .                                          [  OK  ]
    Stopping KPASSWD Service
    Stopping Kerberos 5 Admin Server:                          [  OK  ]
    Stopping KDC Service
    Stopping Kerberos 5 KDC:                                   [  OK  ]
    Stopping Directory Service
    Shutting down dirsrv:
        EXAMPLE-COM...                                         [  OK  ]
        PKI-IPA...                                             [  OK  ]

    After this, the ipa utility will contact the new server through a remote procedure call (RPC).

  4. Remove the RHEL 7 server from the topology by executing the removal commands on the RHEL 8 server. For details, see Uninstalling an IdM server.

Additional resources