Demonstrate GitOps on Managed OpenShift with ArgoCD

Author: Steve Mirman

Video Walkthrough

If you prefer a more visual medium, you can watch Steve Mirman walk through this quickstart on YouTube .

The purpose of this document is to help you get OpenShift GitOps running in your cluster, including deploying a sample application and demonstrating how ArgoCD ensures environment consistency.

This demo assumes you have a Managed OpenShift Cluster available and cluster-admin rights.

GitHub resources referenced in the demo:

• BGD Application: gitops-bgd-app
  
• OpenShift / ArgoCD configuration: gitops-demo

Required command line (CLI) tools

• GitHub: git
• OpenShift: oc
• ArgoCD: argocd
• Kustomize: kam

Environment Set Up

Install the OpenShift GitOps operator

1. Install the OpenShift GitOps operator from the Operator Hub

   

Pull files from GitHub

1. Clone the gitops-demo GitHub repository to your local machine

   git clone https://github.com/rh-mobb/gitops-demo gitops
   

2. Export your local path to the GitHub files

   export GITOPS_HOME="$(pwd)/gitops"
   cd $GITOPS_HOME
   

Log in to OpenShift via the CLI

1. Retrieve the login command from the OpenShift console
   

2. Enter the command in your terminal to authenticate with the OpenShift CLI (oc)

   Output should appear similar to:

   Logged into "https://<YOUR-INSTANCE>.openshiftapps.com:6443" as "<YOUR-ID>" using the token provided.
   

Deploy the ArgoCD Project

Create a new OpenShift project

1. Create a new OpenShift project called gitops

   oc new-project gitops
   

Edit service account permissions

1. Add cluster-admin rights to the openshift-gitops-argocd-application-controller service account in the openshift-gitops namespace

   oc adm policy add-cluster-role-to-user cluster-admin -z openshift-gitops-argocd-application-controller -n openshift-gitops
   

Log in to ArgoCD

1. Retrieve ArgoCD URL:

   argoURL=$(oc get route openshift-gitops-server -n openshift-gitops -o jsonpath='{.spec.host}{"\n"}')
   echo $argoURL
   

2. Retrieve ArgoCD Password:

   argoPass=$(oc get secret/openshift-gitops-cluster -n openshift-gitops -o jsonpath='{.data.admin\.password}' | base64 -d)
   echo $argoPass
   

3. In a browser, navigate to the ArgoCD console using the $argoURL value returned above
   

4. Log in with the user name admin and the password returned as $argoPass above
   

   Optional step if you prefer CLI access Login to the CLI:

   argocd login --insecure --grpc-web $argoURL  --username admin --password $argoPass
   

Deploy the ArgoCD project

1. Use kubectl to apply the bgd-app.yaml file

   kubectl apply -f documentation/modules/ROOT/examples/bgd-app/bgd-app.yaml
   

   The bgd-app.yaml file defines several things, including the repo location for the gitops-bgd-app application
   

2. Check the rollout running the following command:

   kubectl rollout status deploy/bgd -n bgd
   

3. Once the rollout is complete get the route to the application

   oc get route bgd -n bgd -o jsonpath='{.spec.host}{"\n"}'
   

4. In your browser, paste the route to open the application
   

5. Go back to your ArgoCD window and verify the configuration shows there as well
   

6. Exploring the application in ArgoCD, you can see all the components are green (synchronized)
   

Deploy a change to the application

1. In the terminal, enter the following command which will introduce a chance into the bgd application

   kubectl -n bgd patch deploy/bgd --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/env/0/value", "value":"green"}]'
   

2. Go back to your ArgoCD window. The application should no longer be synchronized
   

3. Refresh the bgd application window and notice the change in box color
   

   The new deployment changed the box from blue to green, but only within OpenShift, not in the source code repository

Synchronize the application

1. In the ArgoCD console, click the SYNC button to re-synchronize the bgd application with the approved configuration in the source code repository
   

2. Refresh the bgd application window and notice the change in box color