FreeIPA - Recover a broken replica

It happened to me that a node broke in a way that was not feasible to 'repair'. By broken, I mean that I was not able to recover by re-creating all keytabs for the dirserver and named that were invalid according to the logs.

Anyway, here's the way I took to recover the node and make all nodes replicate again

First, log in to a working node and remove the faulty node from the replication:

 [archy@ipa02 ~]$ ipa server-del ipa01.archyslife.lan \
  --ignore-topology-disconnect  
 -----------------------------------------  
 Deleted IPA server "ipa01.archyslife.lan"  
 -----------------------------------------

If you're running on the latest version of 4.9.6 and EL8.5, you might encounter this error.

After you've removed the host, check if there are any traces left in your ldap tree:

 [archy@ipa02 ~]$ ipa server-find  
 ---------------------  
 2 IPA servers matched  
 ---------------------  
  Server name: ipa02.archyslife.lan  
  Min domain level: 1  
  Max domain level: 1  
  Server name: ipa03.archyslife.lan  
  Min domain level: 1  
  Max domain level: 1  
 ----------------------------  
 Number of entries returned 2  
 ----------------------------  
 [archy@ipa02 ~]$ ipa-replica-manage list  
 ipa02.archyslife.lan: master  
 ipa03.archyslife.lan: master

Check for any leftover replica update vectors:

 [archy@ipa02 ~]$ sudo ipa-replica-manage list-ruv  
 [sudo] password for archy:   
 Directory Manager password:   
 Replica Update Vectors:  
     ipa02.archyslife.lan:389: 11  
     ipa03.archyslife.lan:389: 13  
 Certificate Server Replica Update Vectors:  
     ipa02.archyslife.lan:389: 12  
     ipa03.archyslife.lan:389: 14

If there are any replica update vectors left over, you can use 'ipa-replica-manage clean-ruv ID' to remove them. Once everything is clear, you can continue on uninstalling the ipa-server on the faulty replica and reboot it just to be sure.

 [root@ipa01 ~]# ipa-server-install --uninstall  
 [root@ipa01 ~]# reboot

Once the old faulty server is back online, you can start re-integrating it into the infrastructure. Start by enrolling it into the domain:

 [root@ipa01 ~]# ipa-client-install --unattended 
  --principal 'archy' \
  --domain 'archyslife.lan' \
  --server 'ipa03.archyslife.lan' \
  --realm 'ARCHYSLIFE.LAN' \
  --mkhomedir

Once the old node is re-enrolled into the domain, check if you can kinit as the admin user:

 [root@ipa01 ~]# kinit admin  
 Password for admin@ARCHYSLIFE.LAN:

If that worked, you can go ahead and promote the host to a replica:

 [root@ipa01 ~]# ipa hostgroup-add-member ipaservers \
  --hosts 'ipa01.archyslife.lan'  
 [root@ipa01 ~]# ipa-replica-install \
  --setup-ca \
  --setup-dns \
  --setup-kra \
  --forwarder '1.1.1.1' \
  --forwarder '9.9.9.9' \
  --forward-policy 'only'

This process might take a while to complete. After it's done, check if the ipa services are running:

 [root@ipa01 ~]# ipactl status  
 Directory Service: RUNNING  
 krb5kdc Service: RUNNING  
 kadmin Service: RUNNING  
 named Service: RUNNING  
 httpd Service: RUNNING  
 ipa-custodia Service: RUNNING  
 pki-tomcatd Service: RUNNING  
 ipa-otpd Service: RUNNING  
 ipa-dnskeysyncd Service: RUNNING  
 ipa: INFO: The ipactl command was successful

If you want to make sure that this persists a reboot, you can try stopping and starting (not restarting) the services by using the appropriate 'ipactl stop' and 'ipactl start' commands.

The last thing to do is ensure the replication agreements exist. I'll be using the cli:

 [root@ipa01 ~]# ipa topologysegment-add \
  domain 'ipa02.archyslife.lan-to-ipa01.archyslife.lan' \
  --leftnode 'ipa02.archyslife.lan' \
  --rightnode 'ipa01.archyslife.lan'  
 [root@ipa01 ~]# ipa topologysegment-add \
  domain 'ipa03.archyslife.lan-to-ipa01.archyslife.lan' \
  --leftnode 'ipa03.archyslife.lan' \
  --rightnode 'ipa01.archyslife.lan'  
 [root@ipa01 ~]# ipa topologysegment-add \
  ca 'ipa02.archyslife.lan-to-ipa01.archyslife.lan' \
  --leftnode 'ipa02.archyslife.lan' \
  --rightnode 'ipa01.archyslife.lan'  
 [root@ipa01 ~]# ipa topologysegment-add \
  ca 'ipa03.archyslife.lan-to-ipa01.archyslife.lan' \
  --leftnode 'ipa03.archyslife.lan' \
  --rightnode 'ipa01.archyslife.lan'

By now your servers should all be working and replicating with each other according to the replication agreements.

Feel free to comment and / or suggest a topic.

Comments

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