I am trying to implement CI/CD pipeline for my microservice deployment creating in Spring Boot. I am trying to use my SVN repository, Kubernetes and Jenkins for implementing the pipeline. When I am exploring the deployment using Kubernetes and Jenkins, I found tutorials and many videos for deploying in both test and prod environment by creating and defining in the Jenkinsfile. And also adding the shell script in Jenkins configuration.
Confusion
Here I had felt the doubt that when we are deploying into test environment, how we can deploy the same into prod environment after the proper testing is finished? Do I need to add separate shell script for prod? Or are we deploying serially using one script for both test and prod?
It's completely up to you how you want to do this. In general, we create separate k8s clusters for prod and staging(etc). And your Jenkins needs to deploy to different cluster depending on your pipeline. If you want a true CI/CD, then one pipeline is enough - which will deploy to both the clusters (or environments).
Most of the time businesses don't want CI on production (for obvious reasons). They want manual testing on QA environments before it's deployed to prod.
As k8s is container based, deploying the same image to different envs is really easy. You just build your spring boot app once, and then deploy it to different envs as needed.
A simple pipeline:
If you want to deploy the same to prod, continue the pipeline with (you can pause here for QA as well https://jenkins.io/doc/pipeline/steps/pipeline-input-step/):
If your QA needs more time, then you can also create a different Jenkins job and trigger it manually (even the QA enggs can trigger this)
If you QA and PM are techies, then they can also merge branches or close PRs, which can auto trigger jenkins and run prod deployments.
EDIT (response to comment): You are making REST calls to the k8s API. Even kubectl apply -f foo.yaml will make this rest call. It doesn't matter from where you are making this call - given that your kubectl is configured correctly and can communicate with the k8s server. You can have multiple cluster configured for kubectl and use kubectl --context <staging-cluster> apply -f foo.yaml. You can pick the context name from jenkins env variable or some other mechanism.
We're working on an open source project called Jenkins X which is a proposed sub project of the Jenkins foundation aimed at automating CI/CD on Kubernetes using Jenkins and GitOps for promotion.
When you merge a change to the master branch, Jenkins X creates a new semantically versioned distribution of your app (pom.xml, jar, docker image, helm chart). The pipeline then automates the generation of Pull Requests to promote your application through all of the Environments via GitOps.
Here's a demo of how to automate CI/CD with multiple environments on Kubernetes using GitOps for promotion between environments and Preview Environments on Pull Requests - using Spring Boot and nodejs apps (but we support many languages + frameworks).