5.3. Changing Ignition Configs after installation
Machine config pools manage a cluster of nodes and their corresponding machine configs. Machine configs contain configuration information for a cluster. To list all machine config pools that are known:
$ oc get machineconfigpools
Example output
NAME CONFIG UPDATED UPDATING DEGRADED master master-1638c1aea398413bb918e76632f20799 False False False worker worker-2feef4f8288936489a5a832ca8efe953 False False False
To list all machine configs:
$ oc get machineconfig
Example output
NAME GENERATEDBYCONTROLLER IGNITIONVERSION CREATED OSIMAGEURL 00-master 4.0.0-0.150.0.0-dirty 2.2.0 16m 00-master-ssh 4.0.0-0.150.0.0-dirty 16m 00-worker 4.0.0-0.150.0.0-dirty 2.2.0 16m 00-worker-ssh 4.0.0-0.150.0.0-dirty 16m 01-master-kubelet 4.0.0-0.150.0.0-dirty 2.2.0 16m 01-worker-kubelet 4.0.0-0.150.0.0-dirty 2.2.0 16m master-1638c1aea398413bb918e76632f20799 4.0.0-0.150.0.0-dirty 2.2.0 16m worker-2feef4f8288936489a5a832ca8efe953 4.0.0-0.150.0.0-dirty 2.2.0 16m
The Machine Config Operator acts somewhat differently than Ignition when it comes to applying these machine configs. The machine configs are read in order (from 00* to 99*). Labels inside the machine configs identify the type of node each is for (master or worker). If the same file appears in multiple machine config files, the last one wins. So, for example, any file that appears in a 99* file would replace the same file that appeared in a 00* file. The input MachineConfig objects are unioned into a "rendered" MachineConfig object, which will be used as a target by the operator and is the value you can see in the machine config pool.
To see what files are being managed from a machine config, look for "Path:" inside a particular MachineConfig object. For example:
$ oc describe machineconfigs 01-worker-container-runtime | grep Path:
Example output
Path: /etc/containers/registries.conf Path: /etc/containers/storage.conf Path: /etc/crio/crio.conf
Be sure to give the machine config file a later name (such as 10-worker-container-runtime). Keep in mind that the content of each file is in URL-style data. Then apply the new machine config to the cluster.
