Add new file for pulling images

Author: amolnar-rh

edge_computing/ztp-updating-gitops.adoc

@@ -34,6 +34,8 @@ include::modules/ztp-required-changes-to-the-git-repository.adoc[leveloffset=+1]
 
 include::modules/ztp-installing-the-new-gitops-ztp-applications.adoc[leveloffset=+1]
 
+include::modules/ztp-pulling-ocp-images.adoc[leveloffset=+1]
+
 [role="_additional-resources"]
 .Additional resources
 

modules/ztp-installing-the-new-gitops-ztp-applications.adoc

@@ -8,10 +8,6 @@
 
 Using the extracted `argocd/deployment` directory, and after ensuring that the applications point to your site Git repository, apply the full contents of the deployment directory. Applying the full contents of the directory ensures that all necessary resources for the applications are correctly configured.
 
-.Prerequisites
-
-* You have enabled the assisted service.
-
 .Procedure
 
 include::snippets/ztp-patch-argocd-hub-cluster.adoc[]

modules/ztp-pulling-ocp-images.adoc

@@ -0,0 +1,46 @@
+// Module included in the following assemblies:
+//
+// * scalability_and_performance/ztp_far_edge/ztp-updating-gitops-ztp.adoc
+
+[id="ztp-pulling-ocp-images_{context}"]
+= Enabling pulling ISO images for the desired {product-title} version
+
+To pull ISO images for the desired {product-title} version, update the `AgentServiceConfig` custom resource (CR) with references to the desired ISO and RootFS images that are hosted on the mirror registry HTTP server.
+
+.Prerequisites
+
+* You have installed the OpenShift CLI (`oc`).
+
+* You have logged in to the hub cluster as a user with `cluster-admin` privileges.
+
+* You have {rh-rhacm} with MultiClusterHub enabled.
+
+* You have enabled the assisted service.
+
+.Procedure
+
+. Update the `AgentServiceConfig` CR by running the following command:
++
+[source,terminal]
+----
+$ oc edit AgentServiceConfig
+----
+
+. Add the following entry to the `items.spec.osImages` field in the CR:
++
+[source,yaml,subs="attributes+"]
+----
+- cpuArchitecture: x86_64
+    openshiftVersion: "{product-version}"
+    rootFSUrl: https://<host>/<path>/rhcos-live-rootfs.x86_64.img
+    url: https://<host>/<path>/rhcos-live.x86_64.iso
+----
++
+where:
++
+--
+<host> :: Is the fully qualified domain name (FQDN) for the target mirror registry HTTP server.
+<path> :: Is the path to the image on the target mirror registry.
+--
++
+Save and quit the editor to apply the changes.

modules/ztp-updating-gitops-ztp.adoc

@@ -23,6 +23,6 @@ At a high level, the strategy for updating the {ztp} infrastructure is as follow
 
 . Update required content and optional changes in the Git repository.
 
-. Enable the assisted service to pull ISO images of a newer {product-title} version.
+. Enable pulling the ISO images for the desired {product-title} version.
 
 . Update and restart the application configuration.