Chapter 1. Configuring an OpenShift cluster by deploying an application with cluster configurations

Procedure

1. In the Administrator perspective of the web console, navigate to Operators Installed Operators Red Hat OpenShift GitOps Subscription.
2. Click the Actions drop-down menu then click Edit Subscription.

3. On the openshift-gitops-operator Subscription details page, under the YAML tab, edit the Subscription YAML file by adding the namespace of the Argo CD instance to the ARGOCD_CLUSTER_CONFIG_NAMESPACES environment variable in the spec section:

   apiVersion: operators.coreos.com/v1alpha1
   kind: Subscription
   metadata:
     name: openshift-gitops-operator
     namespace: openshift-operators
   # ...
   spec:
     config:
       env:
       - name: ARGOCD_CLUSTER_CONFIG_NAMESPACES
         value: openshift-gitops, <list of namespaces of cluster-scoped Argo CD instances>
   # ...

4. To verify that the Argo instance is configured with a cluster role to manage cluster-scoped resources, perform the following steps:

   1. Navigate to User Management Roles and from the Filter drop-down menu select Cluster-wide Roles.

   2. Search for the argocd-application-controller by using the Search by name field.

      The Roles page displays the created cluster role.

      Tip

      Alternatively, in the OpenShift CLI, run the following command:

      oc auth can-i create oauth -n openshift-gitops --as system:serviceaccount:openshift-gitops:openshift-gitops-argocd-application-controller

      The output yes verifies that the Argo instance is configured with a cluster role to manage cluster-scoped resources. Else, check your configurations and take necessary steps as required.

Procedure

1. Label the existing nodes:

   $ oc label node <node-name> node-role.kubernetes.io/infra=""

2. Optional: If required, you can also apply taints and isolate the workloads on infrastructure nodes and prevent other workloads from scheduling on these nodes:

   $ oc adm taint nodes -l node-role.kubernetes.io/infra \
   infra=reserved:NoSchedule infra=reserved:NoExecute

3. Add the runOnInfra toggle in the GitOpsService custom resource:

   apiVersion: pipelines.openshift.io/v1alpha1
   kind: GitopsService
   metadata:
     name: cluster
   spec:
     runOnInfra: true

4. Optional: If taints have been added to the nodes, then add tolerations to the GitOpsService custom resource, for example:

     spec:
       runOnInfra: true
       tolerations:
       - effect: NoSchedule
         key: infra
         value: reserved
       - effect: NoExecute
         key: infra
         value: reserved

5. Verify that the workloads in the openshift-gitops namespace are now scheduled on the infrastructure nodes by viewing Pods Pod details for any pod in the console UI.

Procedure

1. In the Argo CD dashboard, click NEW APP to add a new Argo CD application.

2. For this workflow, create a cluster-configs application with the following configurations:

   Application Name

   cluster-configs

   Project

   default

   Sync Policy

   Manual

   Repository URL

   https://github.com/redhat-developer/openshift-gitops-getting-started

   Revision

   HEAD

   Path

   cluster

   Destination

   https://kubernetes.default.svc

   Namespace

   spring-petclinic

   Directory Recurse

   checked

3. Click CREATE to create your application.
4. Open the Administrator perspective of the web console and navigate to Administration Namespaces in the menu on the left.
5. Search for and select the namespace, then enter argocd.argoproj.io/managed-by=openshift-gitops in the Label field so that the Argo CD instance in the openshift-gitops namespace can manage your namespace.

Procedure

1. Download the sample application:

   $ git clone git@github.com:redhat-developer/openshift-gitops-getting-started.git

2. Create the application:

   $ oc create -f openshift-gitops-getting-started/argo/app.yaml

3. Run the oc get command to review the created application:

   $ oc get application -n openshift-gitops

4. Add a label to the namespace your application is deployed in so that the Argo CD instance in the openshift-gitops namespace can manage it:

   $ oc label namespace spring-petclinic argocd.argoproj.io/managed-by=openshift-gitops

Procedure

1. In the Argo CD dashboard, notice that the cluster-configs Argo CD application has the statuses Missing and OutOfSync. Because the application was configured with a manual sync policy, Argo CD does not sync it automatically.
2. Click SYNC on the cluster-configs tile, review the changes, and then click SYNCHRONIZE. Argo CD will detect any changes in the Git repository automatically. If the configurations are changed, Argo CD will change the status of the cluster-configs to OutOfSync. You can modify the synchronization policy for Argo CD to automatically apply changes from your Git repository to the cluster.
3. Notice that the cluster-configs Argo CD application now has the statuses Healthy and Synced. Click the cluster-configs tile to check the details of the synchronized resources and their status on the cluster.
4. Navigate to the OpenShift Container Platform web console and click to verify that a link to the Red Hat Developer Blog - Kubernetes is now present there.

5. Navigate to the Project page and search for the spring-petclinic namespace to verify that it has been added to the cluster.

   Your cluster configurations have been successfully synchronized to the cluster.

Procedure

1. In the web console, select User Management Roles Create Role. Use the following ClusterRole YAML template to add rules to specify the additional permissions.

   apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRole
   metadata:
     name: secrets-cluster-role
   rules:
   - apiGroups: [""]
     resources: ["secrets"]
     verbs: ["*"]

2. Click Create to add the cluster role.
3. To create the cluster role binding, select User Management Role Bindings Create Binding.
4. Select All Projects from the Project drop-down.
5. Click Create binding.
6. Select Binding type as Cluster-wide role binding (ClusterRoleBinding).
7. Enter a unique value for the RoleBinding name.
8. Select the newly created cluster role or an existing cluster role from the drop down list.

9. Select the Subject as ServiceAccount and the provide the Subject namespace and name.

   1. Subject namespace: openshift-gitops
   2. Subject name: openshift-gitops-argocd-application-controller

10. Click Create. The YAML file for the ClusterRoleBinding object is as follows:

    kind: ClusterRoleBinding
    apiVersion: rbac.authorization.k8s.io/v1
    metadata:
      name: cluster-role-binding
    subjects:
      - kind: ServiceAccount
        name: openshift-gitops-argocd-application-controller
        namespace: openshift-gitops
    roleRef:
      apiGroup: rbac.authorization.k8s.io
      kind: ClusterRole
      name: secrets-cluster-role