OSDOCS-12183: adding how to delete manifests

_topic_maps/_topic_map_ms.yml

@@ -195,6 +195,8 @@ Distros: microshift
 Topics:
 - Name: Using Kustomize to deploy applications
   File: microshift-applications
+- Name: Deleting resource manifests
+  File: microshift-deleting-resource-manifests
 - Name: Embedding applications on RHEL for Edge
   File: microshift-embedded-apps-on-rhel-edge
 - Name: Embedding applications for offline use

microshift_running_apps/microshift-deleting-resource-manifests.adoc

@@ -0,0 +1,18 @@
+:_mod-docs-content-type: ASSEMBLY
+[id="microshift-deleting-resource-manifests"]
+= Deleting resource manifests
+include::_attributes/attributes-microshift.adoc[]
+:context: microshift-deleting-resource-manifests
+
+toc::[]
+
+{microshift-short} supports the deletion of resource manifests for the following use cases:
+
+* Data removal - when you need to completely remove a resource from the cluster.
+* Upgrade - during an upgrade, some resources may need to be removed while others are retained to preserve data.
+
+Deleting resource manifests manages the cluster resources efficiently by removing outdated objects while and retaining necessary data.
+
+include::modules/microshift-examples-of-usecase.adoc[leveloffset=+1]
+
+include::modules/microshift-manifests-deletion-overview.adoc[leveloffset=+1]

modules/microshift-examples-of-usecase.adoc

@@ -0,0 +1,33 @@
+// Module included in the following assemblies:
+//
+// * microshift//running_applications/microshift-deleting-resource-manifests.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="microshift-examples-of-usecase_{context}"]
+= Use cases for resource manifest deletion
+
+The following explains the use case in which the resource manifest deletion is used.
+
+== Data removal scenario
+Use the following procedure in the data removal scenario to completely delete the resource defined in the kustomize manifest file.
+
+.Procedure
+
+. Identify the file that needs to be placed in the `delete` subdirectories.
+. Move the manifest file into one of the `delete` subdirectories  under the configured manifests directory by running the following command:
++
+[source,terminal]
+----
+[sudo] mv /usr/lib/microshift/manifests.d/some-user-manifest /usr/lib/microshift/manifests.d/delete/some-user-manifest
+----
+. {microshift-short} detects and removes the resource after the manifest file is placed in the `delete` subdirectories.
+
+
+== Upgrade scenario
+Use the following procedure in the upgrade scenario where some resources need to be removed while retaining others to preserve data.
+
+.Procedure
+
+. Identify the manifest file that requires updating. It is not necessary to include the entire resource `spec` in the `delete` subdirectories.
+. Specify the metadata, such as `name` and `namespace` of the resource to be removed, in the `delete` subdirectories.
+. {microshift-short} detects and removes the specified object without affecting related data.

modules/microshift-manifests-deletion-overview.adoc

@@ -0,0 +1,25 @@
+// Module included in the following assemblies:
+//
+// * microshift//running_applications/microshift-deleting-resource-manifests.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="microshift-manifests-deletion-overview_{context}"]
+= How manifest deletion works
+
+By default, {microshift-short} expects to find deletion manifests in the `delete` subdirectories within the manifest path. When a manifest file is placed in these subdirectories, {microshift-short} automatically handles the removal. Read through the following procedure to understand how manifest file deletion works in {microshift-short}.
+
+.Procedure
+
+. At every start, before applying the manifests, {microshift-short} scans the following `delete` sub directories within the configured manifests directory to identify the Kustomize manifest files that need to be deleted:
+
+* /usr/lib/microshift/manifests/delete
+* /usr/lib/microshift/manifests.d/delete/*
+* /etc/microshift/manifests/delete
+* /etc/microshift/manifests.d/delete/*
+
+. {microshift-short} deletes the resources defined in the kustomize manifest file found in the `delete` directories by running the following command.
++
+[source,terminal]
+----
+kubectl delete -k --ignore-not-found=true
+----