Merge pull request #100946 from openshift-cherrypick-robot/cherry-pick-100697-to-enterprise-4.20

[enterprise-4.20] OCPBUGS 60994 ImageDigestMirrorSet documentation clarifications

Author: mburke5678

modules/images-configuration-registry-mirror.adoc

@@ -65,6 +65,18 @@ Each of these custom resource objects identify the following information:
 requested from the source repository.
 --
 
+Note the following actions and how they affect node drain behavior:
+
+* If you create an IDMS or ICSP CR object, the MCO does not drain or reboot the node. 
+* If you create an ITMS CR object, the MCO drains and reboots the node. 
+* If you delete an ITMS, IDMS, or ICSP CR object, the MCO drains and reboots the node.  
+* If you modify an ITMS, IDMS, or ICSP CR object, the MCO drains and reboots the node.
++
+[IMPORTANT]
+====
+include::snippets/node-icsp-no-drain.adoc[]
+====
+
 ifndef::winc[]
 For new clusters, you can use IDMS, ITMS, and ICSP CRs objects as desired. However, using IDMS and ITMS is recommended.
 

snippets/node-icsp-no-drain.adoc

@@ -2,18 +2,18 @@
 //
 // * modules/understanding-machine-config-operator.adoc
 // * modules/troubleshooting-disabling-autoreboot-mco.adoc
+// * modules/images-configuration-registry-mirror.adoc
 
 :_mod-docs-content-type: SNIPPET
 
-The following modifications do not trigger a node reboot:
-
 * When the MCO detects any of the following changes, it applies the update without draining or rebooting the node:
 
 ** Changes to the SSH key in the `spec.config.passwd.users.sshAuthorizedKeys` parameter of a machine config.
 ** Changes to the global pull secret or pull secret in the `openshift-config` namespace.
 ** Automatic rotation of the `/etc/kubernetes/kubelet-ca.crt` certificate authority (CA) by the Kubernetes API Server Operator.
 
-* When the MCO detects changes to the `/etc/containers/registries.conf` file, such as adding or editing an `ImageDigestMirrorSet`, `ImageTagMirrorSet`, or `ImageContentSourcePolicy` object, it drains the corresponding nodes, applies the changes, and uncordons the nodes. The node drain does not happen for the following changes:
+* When the MCO detects changes to the `/etc/containers/registries.conf` file, such as editing an `ImageDigestMirrorSet`, `ImageTagMirrorSet`, or `ImageContentSourcePolicy` object, it drains the corresponding nodes, applies the changes, and uncordons the nodes. The node drain does not happen for the following changes:
+
 ** The addition of a registry with the `pull-from-mirror = "digest-only"` parameter set for each mirror.
 ** The addition of a mirror with the `pull-from-mirror = "digest-only"` parameter set in a registry.
 ** The addition of items to the `unqualified-search-registries` list.