Comment 7 for bug 1874719

This is a change in the default corosync config file (/etc/corosync/corosync.conf), it impacts pacemaker clusters but it is not directly related to pacemaker. The change was made in Debian here:

https://salsa.debian.org/ha-team/corosync/-/commit/2f8aa88

Between corosync version 2.4.3 (present in Bionic) and version 3.0.3 (present in Focal) the 'nodelist' directive became required (as you can see in the commit message above). The decision was to configure a single node called 'node1' with 127.0.0.1 as the IP address link. This is not done in Bionic.

To fix this and keep the old behavior (use the hostname instead of a hardcoded 'node1') we simply need to comment out the "name: node1" line in /etc/corosync/corosync.conf. I did the following in a Focal VM to test it:

$ sudo apt-get install -y crmsh pacemaker
$ sudo crm status
Cluster Summary:
  * Stack: corosync
  * Current DC: node1 (version 2.0.3-4b1f869f0f) - partition with quorum
  * Last updated: Thu Jun 10 11:23:33 2021
  * Last change: Thu Jun 10 11:05:11 2021 by hacluster via crmd on node1
  * 1 node configured
  * 0 resource instances configured

Node List:
  * Online: [ node1 ]

Full List of Resources:
  * No resources

$ sudo sed -e '/name: node1/s/^/#/' -i /etc/corosync/corosync.conf
$ sudo systemctl restart corosync
$ sudo systemctl restart pacemaker
$ $ sudo crm status
Cluster Summary:
  * Stack: corosync
  * Current DC: focal (version 2.0.3-4b1f869f0f) - partition with quorum
  * Last updated: Thu Jun 10 11:51:08 2021
  * Last change: Thu Jun 10 11:36:45 2021 by hacluster via crmd on focal
  * 1 node configured
  * 0 resource instances configured

Node List:
  * Online: [ focal ]

Full List of Resources:
  * No resources

In this case my hostname is 'focal', so I believe this will keep the old behavior. Do you believe this worth a SRU? Would you like me to work on this?