Having a factory (edge) cluster join the datacenter (hub)

Allow ACM to deploy the factory application to a subset of clusters

By default the factory applications are deployed on all clusters that ACM knows about.

  managedSites:
  - name: factory
    clusterSelector:
      matchExpressions:
      - key: vendor
        operator: In
        values:
          - OpenShift

This is useful for cost-effective demos, but is hardly realistic.

To deploy the factory applications only on managed clusters with the label site=factory, change the site definition in values-datacenter.yaml to:

  managedSites:
  - name: factory
    clusterSelector:
      matchLabels:
        site: factory

Remember to commit the changes and push to GitHub so that GitOps can see your changes and apply them.

Deploy a factory cluster

Rather than provide instructions on creating a factory 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 factory to the datacenter.

• Using the ACM user interface
• Using the cm tool
• Using the clusteradm tool

Factory 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 site=factory Press import. Done.

Using this method, you are done. Skip to the section Factory is joined but ignore the part about adding the site tag.

Factory setup using cm tool

1. Install the cm (cluster management) command-line tool. See details here

2. Obtain the KUBECONFIG file from the edge/factory cluster.

3. On the command-line login into the hub/datacenter cluster (use oc login or export the KUBECONFIG).

4. Run the following command:

cm attach cluster --cluster <cluster-name> --cluster-kubeconfig <path-to-KUBECONFIG>

Skip to the section Factory is joined

Factory 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.

1. 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

2. When you run the clusteradm command above it replies with the token and also shows you the command to use on the factory. So first you must login to the factory cluster

   oc login or

   export KUBECONFIG=~/my-ocp-env/factory

3. Then request to that the factory join the datacenter hub

   clusteradm join --hub-token <token from clusteradm get token command > <factory cluster name>

4. Back on the hub cluster accept the join request

   clusteradm accept --clusters <factory-cluster-name>

Skip to the next section, Factory is joined

Factory is joined

Designate the new cluster as a factory site

Now that ACM is no longer deploying the factory applications everywhere, we need to explicitly indicate that the new cluster has the factory role. If you haven’t tagged the cluster as site=managed-cluster then we can that here.

We do this by adding the label referenced in the managedSite’s clusterSelector.

1. Find the new cluster

   oc get managedclusters.cluster.open-cluster-management.io

2. Apply the label

   oc label managedclusters.cluster.open-cluster-management.io/YOURCLUSTER site=factory

You’re done

That’s it! Go to your factory (edge) 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 Industrial Edge 2.0 GitOps/DevOps demos