Having a production cluster join the hub
Introduction
Production clusters need to be secured and so one part of the deployment is to install the Advanced Cluster Security operator with a secured configuration. This allows ACS central to monitor and report on security issues on the cluster. ACS secured sites report to an ACS Central application that is deployed on the hub.
Allow ACM to deploy the production application to a subset of secured clusters
By default the production applications are deployed on all prod
clusters that ACM knows about.
- name: secured
helmOverrides:
- name: clusterGroup.isHubCluster
value: "false"
clusterSelector:
matchLabels:
clusterGroup: prod
matchExpressions:
- key: vendor
operator: In
values:
- OpenShift
Remember to commit the changes and push to GitHub so that GitOps can see your changes and apply them.
Deploy a production cluster
Rather than provide instructions on creating a production cluster it is assumed
that an OpenShift cluster has already been created. Use the openshift-install
program provided at cloud.redhat.com
There are a three ways to join the production to the datacenter.
- Using the ACM user interface
- Using the
cm
tool - Using the
clusteradm
tool
Production cluster setup using the ACM UI
After ACM is installed a message regarding a “Web console update is available” may be displayed. Click on the “Refresh web console” link.
On the upper-left side you’ll see a pull down labeled “local-cluster”. Select “All Clusters” from this pull down. This will navigate to the ACM console and to its “Clusters” section
Select the “Import cluster” option beside the highlighted Create Cluster button.
On the “Import an existing cluster” page, enter the cluster name and choose Kubeconfig as the “import mode”. Add the tag clusterGroup=prod
Press import. Done.
Using this method, you are done. Skip to the section Production is joined but ignore the part about adding the site tag.
Production setup using cm
tool
Install the
cm
(cluster management) command-line tool. See details hereObtain the KUBECONFIG file from the managed production (prod) cluster.
On the command-line login into the hub/datacenter cluster (use
oc login
or export the KUBECONFIG).Run the following command:
cm attach cluster --cluster <cluster-name> --cluster-kubeconfig <path-to-KUBECONFIG>
Skip to the section Production is joined
Production setup using clusteradm
tool
You can also use clusteradm
to join a cluster. The following instructions explain what needs to be done. clusteradm
is still in testing.
To deploy a edge cluster you will need to get the datacenter (or hub) cluster’s token. You will need to install
clusteradm
. On the existing datacenter cluster:clusteradm get token
When you run the
clusteradm
command above it replies with the token and also shows you the command to use in production. So first you must login to the production clusteroc login
orexport KUBECONFIG=~/my-ocp-env/prod
Then request to that the production join the datacenter hub
clusteradm join --hub-token <token from clusteradm get token command > <production cluster name>
Back on the hub cluster accept the join request
clusteradm accept --clusters <production-cluster-name>
Skip to the next section, Production is joined
Production is joined
Designate the new cluster as a production site
Now that ACM is no longer deploying the production applications everywhere, we need
to explicitly indicate that the new cluster has the production role. If you haven’t tagged the cluster as clusterGroup=prod
then we can that here.
We do this by adding the label referenced in the managedSite’s clusterSelector
.
Find the new cluster
oc get managedclusters.cluster.open-cluster-management.io
Apply the label
oc label managedclusters.cluster.open-cluster-management.io/YOURCLUSTER clusterGroup=prod
You’re done
That’s it! Go to your production OpenShift console and check for the open-cluster-management-agent pod being launched. Be patient, it will take a while for the ACM agent and agent-addons to launch. After that, the operator OpenShift GitOps will run. When it’s finished coming up launch the OpenShift GitOps (ArgoCD) console from the top right of the OpenShift console.
Next up
Work your way through the Multicluster DevSecOps GitOps/DevOps demos (TBD)