CI part is achieved using Jenkins and for CD, ArgoCD is being used to deploy the Kubernetes manifests for SpringBoot application on Staging and Production namespaces on Kubernetes.

https://github.com/shobhans/argocd_app_k8s_manifests.git

This repo includes Jenkinsfile for the pipeline and build template for jenkins agents on Kubernetes. The Jenkins pipeline contains following 6 stages with human intervention to proceed to production deploy (stage 6):

1. Declarative: Checkout SCM
2. Build Maven project & Archive Artifact
3. Kaniko Build & Push Image
4. Checkout K8S manifest SCM
5. Staging Deploy - Update K8S manifest & push to Repo
6. Prod Deploy - Update K8S manifest & push to Repo

Kaniko needs dockerhub credential to push images to registry. The credential secret is mounted as a volume to the kaniko container inside jenkins agent pod. Create docker registry credential secret using the following command.

kubectl -n jenkins create secret docker-registry dockercred \
 --docker-server=https://index.docker.io/v1/ \
 --docker-username=my-docker-username \
 --docker-password='my-secret-password' \
 [email protected]

• Stages from 3 (Kaniko Build & Push Image) to 6 (Prod Deploy) only execute for 'main' branch.
• Tests are skipped to keep this demo simple.
• Container image is built using Kanino and pushed to Dockerhub image registry.
• Stage 5 and 6 update K8S manifest repo.
• ArgoCD monitors K8S manifests repo and creates/updates resources(deployment, service) on K8S.
• For automatic invocation of the Jenkins pipeline, you have to setup a Github webhook.
• On this demo, Jenkins is running within K8S (installed using helm chart, ref link provided below) and jobs are executed by its agents (template - builder.yaml).
• on builder.yaml, a persistentVolumeClaim 'maven-pv-claim' is used to cache repo dependencies for maven. This pvc must be created in prior. Using a pvc is optional; pvc not created, builder.yaml should be updated accordingly.

Services are using NodePort on this demo. To visit the running application after a successful deploy visit the following link:

• http://{type-node-ip-address}:30083 (staging)
• http://{type-node-ip-address}:30082 (prod)

• Install Jenkins on K8S using helm - https://github.com/shobhans/jenkins-using-helm-on-k8s
• Getting started with ArgoCD - https://argo-cd.readthedocs.io/en/stable/getting_started/
• Create SpringBoot App - https://start.spring.io/