hostname_validation.md

Scenario 1

Mismatch fqdn vs hostname.

3.9 install

Ensure output of 'hostname' != 'hostname -f' on each host.

EG:

$ hostname
myhost
$ hostname -f
myhost.example.com

Install 3.9 as normal.

3.10 upgrade verify fail

Run upgrade, should fail early with hostname mismatch.

3.10 upgrade fix

Set each host to have output of 'hostname' == 'hostname -f' via hostnamectl.

Rerun upgrade, upgrade should complete without issue.

Scenario 2

Mismatch hostname vs openshift_hostname

3.9 install

Ensure openshift_hostname is set in inventory for each host, and that it is resolvable. Also ensure that openshift_hostname != 'hostname' output. This might require custom DNS or on aws (without using cloudprovider) you might be able to set openshift_hostname to external ec2 names (depending on if each host can connect to each other via external names).

3.10 upgrade verify fail

Should fail same as scenario 1.

3.10 upgrade fix

Set openshift_kubelet_name_override to value openshift_hostname.

Remove openshift_hostname from inventory for each host.

Run upgrade, it should complete successfully.

Verify on each node the last line of node-config.yml contains "nodeName: $openshift_kubelet_name_override"

Scenario 3

Verify you can scale up a node to cluster from scenario 2.

Scale up fail

Attempt to set openshift_kubelet_name_override for the scale up host.

Install should fail.

Scale up success

Remove openshift_kubelet_name_override only from new host, run scaleup.

Install should succeed.

Scenario 4

On both 3.10 and 3.11 branches, try to install a new cluster with openshift_kubelet_name_override set. Installs should fail. Installs should proceed without this value.