Documentation of Codebase

Project Topic:- Dockerizing a simple web application, deploy it to a Kubernetes cluster using Argo CD, and manage its release process with Argo Rollouts.

Prerequisites:-

• Experience with Git principles for version control.

• Experience with GitHub to fork, clone or publish a repository.

• Containerization using Docker and a container registry like Docker Hub.

• Familiarity with Kubernetes Concepts like - Pods, Services, Deployments and Clusters.

• Basics of GitOps tools like Argo CD and Argo Rollouts.

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Our Repo structure is given below:-

 Argo-GitOps
 |_ Source
 |  |_ Dockerfile
 |  |_ .dockerignore
 |  |_ index.js
 |  |_ .gitignore
 |  |_ package.json
 |
 |_ Rollout
 |  |_ svc.yaml
 |  |_ ro.yaml
 |
 |_ .kube
 |  |_ config.yaml
 |
 |_ README.md

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Step 1:- Creating a Git repository that hosts our code

• You can use your code editor like VSCode to publish the repository directly.
• Alternatively, you can use git commands to publish the source code, right click on the folder and select "git bash here".
  • Create a new repository on your GitHub and copy the link.
  • Enter below provided commands on the terminal:-

     git init
     git add .
     git commit -m "Your commit message here"
     git remote add origin <repository_clone_link>
     git push -u origin master
  

Step 2:- Installing Argo tools on our Kubernetes Cluster

Note:- The Docker Desktop should be up and running from here until you are monitoring the deployment and changes.

• Command to run your Kubernetes cluster

   minikube start
  

• If faced with any confusion, refer to the original documentation of Kuberentes:- Learn Kubernetes Basics | Kubernetes

• Commands to install Argo CD to your cluster

   kubectl create namespace argocd
   kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml 
  

• Commands to install Argo Rollout to your cluster

   kubectl create namespace argo-rollouts
   kubectl apply -n argocd -f https://github.com/argoproj/argo-rollouts/releases/latest/download/install.yaml 
  

Step 3:- Dockerizing the Application

• Creating a Dockerfile to isolate the source code, and a .dockerignore file to hide the unnecessary modules from the container. [docker commands rest in: Source -> Dockerfile]
• Run the build command and push command to push the docker image to docker hub.

   docker build -t {username}/{reponame}:{tag}                      
   docker push {username}/{reponame}:{tag}			         
  

• If faced with any confusion, refer to the original documentation of Docker:- Packaging your software | Docker Docs

Step 4:- Deploying the application

• Modify Kubernetes manifests or kubeconfig file (./kube/config.yaml) to use the docker image previously pushed.

• Login to Argo CD using:-

    kubectl get all -n argocd                                        #identify the port for Argo CD 
    kubectl port-forward service/argocd-server -n argocd 8080:443    #runs the Argo Web GUI on 127.0.0.1:8080
  

• Login Page looks like this:

• Default username is "admin" and to get the password run the following command :

kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d

• It will open up such an interface:
• Press + NEW APP button and specify your project details on the interface to monitor the deployed pod(s).
• Make sure the sync policy is set to Automatic.
• If faced with any confusion, refer to the original documentation of Argo :- Argo CD | Argo (argoproj.github.io) or this youtube video:-https://youtu.be/JLrR9RV9AFA?feature=shared

Step 5:- Defining a rollout strategy

• Define a Rollout resource (equivalent to a Deployment) in your project’s Kubernetes manifests under Rollout directory.

• Specify the canary strategy in the rollout definition.

• Set the initial canary weight (e.g., 10%), pause for a specified duration (e.g., 1 hour) to monitor behavior, gradually increase the canary weight (e.g., 20%).

Step 6:- Implementing the Canary Release strategy with Argo CD

• Commit your updated Kubernetes manifests to your GitHub repository.

• Update your Docker image with updated source code and push the image to Docker Hub.

• Modify the rollout definition to use the new image.

• Use ArgoCD to sync your application with the updated manifests.

Step 7:- Monitoring the release and changes

• ArgoCD will manage the rollout process based on the canary strategy.

• Observe the behavior of the canary version.

• Verify that the canary behaves as expected.

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Cleanup of Kubernetes Cluster:-

• Delete the Argo Rollouts using the following command:

   kubectl delete rollouts {rollout-name}
  

• Delete the Argo CD application using the argocd CLI:

   argocd app delete {app-name}
  

• Delete the Kubernetes Deployment using the following command:

   kubectl delete deployment {deployment-name}
  

• Delete the Docker Image from the Docker Hub using the Docker Hub UI or the Docker CLI. Please refer to the Docker Hub documentation for the specific steps:- Overview of Docker Hub | Docker Docs.

• Delete the Kubernetes Cluster using the following command:

   minikube delete
  

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Challenges and Solutions:-

• Docker is more than just images. Its a containerization tool where our code is isolated and managed. To understand the docker well, we can refer to this video for simplified but quick explanation:- https://youtu.be/gAkwW2tuIqE?feature=shared
• Kubernetes is not difficult but learning Kubernetes is rather a long process, the documentation is enough:- Learn Kubernetes Basics | Kubernetes
• I personally felt that Argo CD and Argo Rollouts is rather difficult to understand through documentation and some of the commands are not explicitly mentioned.
• This led me into an infinite confusions of deployments to containers and trying to install the CLI, which is not straightforward for Windows users(like me), and so I referred to this youtube video :- https://youtu.be/JLrR9RV9AFA?feature=shared
• By no chance I am saying their documentation is bad but GitOps intersects so many concepts together, which is not elaborated in the documentation, thus not very beginner-friendly.

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THROUGH THIS PROJECT I GOT TO LEARN A LOT OF THINGS HAPPENING ON THE DEPLOYMENT SIDE OF PROJECTS.

MAKE SURE TO STAR THIS REPO IF YOU ENJOYED GITOPS😊.