Java Application CI/CD Deployment on OpenShift using ArgoCD and BuildConfig

This project demonstrates an automated CI/CD pipeline setup using ArgoCD for GitOps-based deployment and OpenShift's BuildConfig for building the Docker image on OpenShift. The application is deployed in two environments: bog-dev and bog-prd. All configurations, including namespaces, image build, and routes, are managed via Git without the use of webhooks.

Project Structure

java-app/
├── app-code/                  # Application source code and Dockerfile
│   ├── src/
│   ├── Dockerfile
│   └── pom.xml
└── k8s-manifests/             # Kubernetes manifests for ArgoCD deployment
    ├── base/                  # Base configuration used across environments
    │   ├── deployment.yaml
    │   ├── service.yaml
    │   ├── imagestream.yaml
    │   └── kustomization.yaml
    │   └── mysql-deployment.yaml
    │   └── mysql-pvc.yaml
    │   └── mysql-secret.yaml
    │   └── mysql-service.yaml  
    └── overlays/              # Environment-specific overlays
        ├── bog-dev/           # Dev overlay with namespace and image configs
        │   ├── kustomization.yaml
        │   ├── namespace.yaml
        │   ├── buildconfig.yaml
        │   └── route.yaml
        └── bog-prd/           # Prod overlay with namespace and image configs
            ├── kustomization.yaml
            ├── namespace.yaml
            ├── buildconfig.yaml
            └── route.yaml
    └── argocd-applications/   # ArgoCD applications for each environment
        ├── argocd-application-dev.yaml
        └── argocd-application-prd.yaml

Step-by-Step Setup Instructions

Step 1: Push Code and Manifests to Git Repository

1. Fork or clone this repository.
2. Push all application code and Kubernetes manifests to your own Git repository: https://github.com/george-cassar/java-app.git.

Step 2: OpenShift Project Setup with ArgoCD

ArgoCD will create and manage the bog-dev and bog-prd namespaces automatically.

Step 3: Configure BuildConfig for Image Build

1. The BuildConfig in pipeline/buildconfig.yaml is used to build and push the Docker image.
2. This file does not use webhooks and allows manual or configuration-based triggering.

Step 4: Configure Kubernetes Manifests with Kustomize

1. Define common resources (deployment.yaml, service.yaml, and imagestream.yaml) in the base directory.
2. Create environment-specific overlays in overlays/bog-dev and overlays/bog-prd for each namespace and route.

Step 5: Add Namespace Manifests in Overlays

The namespace.yaml files in each overlay ensure namespaces are created automatically by ArgoCD if they don't already exist.

Step 6: Configure Kustomize Overlays

In each overlay, set up Kustomize to dynamically reference the correct namespace and image path.

Step 7: Set Up ArgoCD Applications for Each Environment

In argocd-applications/, the ArgoCD applications for bog-dev and bog-prd are defined to monitor and deploy the changes.

Step 8: Apply ArgoCD Applications

Apply the ArgoCD applications to your OpenShift cluster:

oc apply -f k8s-manifests/argocd-application-dev.yaml
oc apply -f k8s-manifests/argocd-application-prd.yaml

Step 9: Trigger the Build Manually

Since no webhooks are used, trigger the build manually:

oc start-build java-app-build -n bog-dev
oc start-build java-app-build -n bog-prd

ArgoCD will automatically detect any updates in the Git repository and sync them to the OpenShift environment.

Summary

This setup automates building and deploying the application to multiple environments using ArgoCD for GitOps-based deployment and OpenShift's BuildConfig for the CI build process.