OpenShift GitOps

• OpenShift GitOps
  • GitOps Operator
    • ArgoCD CLI
    • Add Cluster
  • ArcoCD Applications
    • Frontend/Backend App
    • Todo App
      • Phase and Sync-Wave
  • ArgoCD Web Console

GitOps Operator

• Install OpenShift GitOps Operator

  

• Wait for few minutes. Check ArgoCD's pods in openshift-gitops namespace

  oc get pods -n openshift-gitops
  

  Output

  NAME                                                          READY   STATUS    RESTARTS   AGE
  cluster-d469b8c87-hj4td                                       1/1     Running   0          68s
  kam-6976788946-fdhfd                                          1/1     Running   0          68s
  openshift-gitops-application-controller-0                     1/1     Running   0          66s
  openshift-gitops-applicationset-controller-66db7bd58c-mfp4v   1/1     Running   0          66s
  openshift-gitops-dex-server-8bd64f9f7-c5lt4                   1/1     Running   0          65s
  openshift-gitops-redis-7867d74fb4-6mnwk                       1/1     Running   0          66s
  openshift-gitops-repo-server-55959654b4-t6jrh                 1/1     Running   0          66s
  openshift-gitops-server-6776b46d54-czc89                      1/1     Running   0          66s
  

• Access ArgoCD Console.

  • Select Cluster Argo CD from top menu bar

    

  • By CLI

    ARGOCD=$(oc get route/openshift-gitops-server -n openshift-gitops -o jsonpath='{.spec.host}')
    echo https://$ARGOCD
    

  Notice that ArgoCD route is passtrough.

  • Extract password from secret

    PASSWORD=$(oc extract secret/openshift-gitops-cluster -n openshift-gitops --to=-) 2>/dev/null
    echo $PASSWORD
    

• Install argocd cli. For OSX use brew

  brew install argocd
  

ArgoCD CLI

• login to argocd

  argocd login $ARGOCD  --insecure \
  --username admin \
  --password $PASSWORD
  

  Output

  'admin:login' logged in successfully
  Context 'openshift-gitops-server-openshift-gitops.apps.cluster-0e2b.0e2b.sandbox563.opentlc.com' updated
  

• Use oc or kubectl CLI to login to target cluster and rename context

  Remark: In this demo, Target cluster is the same cluster as ArgoCD cluster. If target cluster is another cluster then use oc command to login to target cluster first.

  oc config rename-context $(oc config current-context) dev-cluster
  

  Output

  Context "default/api-cluster-0e2b-0e2b-sandbox563-opentlc-com:6443/opentlc-mgr" renamed to "dev-cluster".
  

Add Cluster

• Use argocd CLI to add current cluster to be managed by ArgoCD

  argocd cluster add dev-cluster
  

  Output

  INFO[0001] ServiceAccount "argocd-manager" already exists in namespace "kube-system"
  INFO[0001] ClusterRole "argocd-manager-role" updated
  INFO[0002] ClusterRoleBinding "argocd-manager-role-binding" updated
  Cluster 'https://api.cluster-0e2b.0e2b.sandbox563.opentlc.com:6443' added
  

ArcoCD Applications

Frontend/Backend App

• Create application demo-dev-cluster

  oc apply -f manifests/gitops/applications/demo-dev-cluster.yaml
  

  Output

  application.argoproj.io/demo-dev-cluster created
  

• Check application demo-dev-cluster status

  oc get application -n openshift-gitops
  

  Output

  NAME               SYNC STATUS   HEALTH STATUS
  demo-dev-cluster   Synced        Healthy
  

• demo-dev-cluster use kustomize and configured to manifests/apps-kustomize/overlyas/dev

  manifests/apps-kustomize
  ├── base
  │   ├── backend-service.yaml
  │   ├── backend.yaml
  │   ├── demo-rolebinding.yaml
  │   ├── frontend-service.yaml
  │   ├── frontend.yaml
  │   ├── kustomization.yaml
  │   ├── namespace.yaml
  │   └── route.yaml
  └── overlays
      ├── dev
      │   ├── backend.yaml
      │   ├── frontend.yaml
      │   └── kustomization.yaml
      └── prod
          ├── backend.yaml
          ├── frontend.yaml
          └── kustomization.yaml
  

Todo App

Order of operation sync by ArgoCD can be managed by Phase and Wave

Phase and Sync-Wave

todo-dev-cluster is ordered by todo-db, todo app and service montioring.

• Create application todo-dev-cluster

  oc apply -f manifests/gitops/applications/todo-dev-cluster.yaml
  

• Check for Hook and Wave in

  • Todo Database todo-db.yaml

    • Secret sync-wave -1
    • PVC and Deployment sync-wave 1

      annotations:
        argocd.argoproj.io/hook: PreSync
        argocd.argoproj.io/sync-wave: "1"
    

  • Todo App todo.yaml

     annotations:
       argocd.argoproj.io/hook: Sync
       argocd.argoproj.io/sync-wave: "1"
    

ArgoCD Web Console

• Walkthrough ArgoCD console

  • Open ArgoCD URL

    

  • Application status

    Overall

    

    Reference to git commit

    

  • Application topology

    

  • Node topology

    

  • Pod's log