Chapter 2. Using Progressive Sync in OpenShift GitOps

Procedure

1. Set the RollingSync parameter for the ApplicationSet spec. The following example contains a sample YAML configuration.

   Example enabling rollingsync parameter to use Progressive Sync:

   apiVersion: argoproj.io/v1alpha1
   kind: ApplicationSet
   metadata:
     name: guestbook-rollingsync
     namespace: openshift-gitops
   spec:
     generators:
       - list:
           elements:
             - cluster: in-cluster
               env: dev
             - cluster: in-cluster
               env: qa
             - cluster: in-cluster
               env: prod
     strategy:
       type: RollingSync
       rollingSync:
         steps:
           - matchExpressions:
               - key: envLabel
                 operator: In
                 values: [dev]
           - matchExpressions:
               - key: envLabel
                 operator: In
                 values: [qa]
             maxUpdate: 0
           - matchExpressions:
               - key: envLabel
                 operator: In
                 values: [prod]
             maxUpdate: 10%
     template:
       metadata:
         name: 'guestbook-{{.env}}'
         labels:
           envLabel: '{{.env}}'
       spec:
         project: default
         source:
           repoURL: https://github.com/your-org/your-repo.git
           targetRevision: HEAD
           path: guestbook/{{.env}}
         destination:
           server: https://kubernetes.default.svc
           namespace: guestbook-{{.env}}

2. Apply the YAML file by running the following command:

   $ oc apply -f guestbook-rollingsync.yaml

   Note
   • When deploying an application by using the ApplicationSet controller, the Argo CD controller will only manage an application in its own namespace. If an application is created in another namespace, it will not be recognized.
   • RollingSync updates application groups sequentially based on matchExpressions, and the rollingSync.steps field defines which groups to sync and in what order using label selectors.

3. Verify that Red Hat OpenShift GitOps Operator has enabled Progressive Sync in the Argo CD Web UI by completing the following steps:

   1. In the Argo CD Web UI, navigate to the Argo CD Application details page for your deployed application.

   2. In the Application Status panel, a new section, PROGRESSIVE SYNC appears if the Progressive Sync feature is enabled successfully for your application.

      The Progressive Sync panel displays the following information:

   Progressive Sync status fields:

   Field	Description
   Progressive Sync Status	Health status: Waiting, Pending, Progressing, Healthy, or Error
   Wave	Current rollout wave number
   Last Transition	Timestamp of the last state change
   Message	Additional details or error messages