chore: Restore installing image puller on openshift using cli

modules/administration-guide/pages/caching-images-for-faster-workspace-start.adoc

@@ -22,6 +22,8 @@ therefore improving the workspace start time.
 
 * xref:installing-image-puller-on-openshift-by-using-the-web-console.adoc[]
 
+* xref:installing-image-puller-on-openshift-using-cli.adoc[]
+
 * xref:configuring-image-puller-to-pre-pull-default-che-images.adoc[]
 
 * xref:configuring-image-puller-to-pre-pull-custom-images.adoc[]

modules/administration-guide/pages/installing-image-puller-on-openshift-using-cli.adoc

@@ -0,0 +1,159 @@
+:_content-type: PROCEDURE
+:description: Installing {image-puller-name-short} on OpenShift using CLI
+:keywords: administration-guide, image-puller, openshift, openshift-templates, CLI
+:navtitle: Installing {image-puller-name-short} on OpenShift using CLI
+//:page-aliases: .:installing-image-puller-on-openshift-using-openshift-templates.adoc,installing-image-puller-on-openshift-using-openshift-templates.adoc
+
+[id="installing-image-puller-on-openshift-using-the-cli"]
+= Installing {image-puller-name-short} on OpenShift by using the CLI
+
+You can install the {image-puller-name} on OpenShift by using OpenShift `oc` management tool.
+
+.Prerequisites
+
+* An active `oc` session with administrative permissions to the OpenShift cluster. See link:https://docs.openshift.com/container-platform/{ocp4-ver}/cli_reference/openshift_cli/getting-started-cli.html[Getting started with the OpenShift CLI].
+
+.Procedure
+
+. Gather a list of relevant container images to pull by navigating to the links:
+* `pass:c,a,q[{prod-url}]/plugin-registry/v3/external_images.txt`
+* `pass:c,a,q[{prod-url}]/devfile-registry/devfiles/external_images.txt`
+
+. Define the memory requests and limits parameters to ensure pulled containers and the platform have enough memory to run.
++
+When defining the minimal value for `CACHING_MEMORY_REQUEST` or `CACHING_MEMORY_LIMIT`, consider the necessary amount of memory required to run each of the container images to pull.
++
+When defining the maximal value for `CACHING_MEMORY_REQUEST` or `CACHING_MEMORY_LIMIT`, consider the total memory allocated to the DaemonSet Pods in the cluster:
++
+----
+(memory limit) * (number of images) * (number of nodes in the cluster)
+----
++
+====
+Pulling 5 images on 20 nodes, with a container memory limit of `20Mi` requires `2000Mi` of memory.
+====
+
+. Clone the {image-puller-name-short} repository and get in the directory containing the OpenShift templates:
++
+[subs="+attributes,+quotes"]
+----
+$ git clone https://github.com/che-incubator/{image-puller-repository-name}
+$ cd {image-puller-repository-name}/deploy/openshift
+----
+
+. Configure the `app.yaml`, `configmap.yaml` and `serviceaccount.yaml` OpenShift templates using following parameters:
++
+.{image-puller-name-short} OpenShift templates parameters in `app.yaml`
+[options="header"]
+|===
+|Value |Usage |Default
+
+|`DEPLOYMENT_NAME`
+|The value of `DEPLOYMENT_NAME` in the ConfigMap
+|`{image-puller-deployment-name}`
+
+|`IMAGE`
+|Image used for the `{image-puller-deployment-name}` deployment
+|`{image-puller-image-name}`
+
+|`IMAGE_TAG`
+|The image tag to pull
+|`latest`
+
+|`SERVICEACCOUNT_NAME`
+|The name of the ServiceAccount created and used by the deployment
+|`kubernetes-image-puller`
+
+|===
++
+.{image-puller-name-short} OpenShift templates parameters in `configmap.yaml`
+[options="header"]
+|===
+|Value |Usage |Default
+
+|`CACHING_CPU_LIMIT`
+|The value of `CACHING_CPU_LIMIT` in the ConfigMap
+|`.2`
+
+|`CACHING_CPU_REQUEST`
+|The value of `CACHING_CPU_REQUEST` in the ConfigMap
+|`.05`
+
+|`CACHING_INTERVAL_HOURS`
+|The value of `CACHING_INTERVAL_HOURS` in the ConfigMap
+|``"1"``
+
+|`CACHING_MEMORY_LIMIT`
+|The value of `CACHING_MEMORY_LIMIT` in the ConfigMap
+|`"20Mi"`
+
+|`CACHING_MEMORY_REQUEST`
+|The value of `CACHING_MEMORY_REQUEST` in the ConfigMap
+|`"10Mi"`
+
+|`DAEMONSET_NAME`
+|The value of `DAEMONSET_NAME` in the ConfigMap
+|`{image-puller-deployment-name}`
+
+|`DEPLOYMENT_NAME`
+|The value of `DEPLOYMENT_NAME` in the ConfigMap
+|`{image-puller-deployment-name}`
+
+|`IMAGES`
+|The value of `IMAGES` in the ConfigMap
+|`{}`
+
+|`NAMESPACE`
+|The value of `NAMESPACE` in the ConfigMap
+|`{image-puller-namespace}`
+
+|`NODE_SELECTOR`
+|The value of `NODE_SELECTOR` in the ConfigMap
+|`"{}"`
+|===
++
+.{image-puller-name-short} OpenShift templates parameters in `serviceaccount.yaml`
+[options="header"]
+|===
+|Value |Usage |Default
+
+|`SERVICEACCOUNT_NAME`
+|The name of the ServiceAccount created and used by the deployment
+|`kubernetes-image-puller`
+
+|===
+
+
+
+. Create an OpenShift project to host the {image-puller-name-short}:
++
+[subs="+attributes,+quotes"]
+----
+$ oc new-project __<{image-puller-namespace}>__
+----
+
+. Process and apply the templates to install the puller:
++
+[subs="+attributes,+quotes"]
+----
+$ oc process -f serviceaccount.yaml | oc apply -f -
+$ oc process -f configmap.yaml | oc apply -f -
+$ oc process -f app.yaml | oc apply -f -
+----
+
+
+.Verification steps
+
+. Verify the existence of a __<{image-puller-deployment-name}>__ deployment and a __<{image-puller-deployment-name}>__ DaemonSet. The DaemonSet needs to have a Pod for each node in the cluster:
++
+[source%nowrap,dummy,subs="+quotes,+attributes"]
+----
+$ oc get deployment,daemonset,pod --namespace __<{image-puller-namespace}>__
+----
+
+. Verify the values of the __<{image-puller-deployment-name}>__ `ConfigMap`.
++
+[source%nowrap,dummy,subs="+quotes,+attributes"]
+----
+$ oc get configmap __<{image-puller-deployment-name}>__ --output yaml
+----