# CI/CD Pipeline using GitHub Actions, Harbor Container Registry, ArgoCD, Kubernetes, and NGINX [Overview]

This pipeline is implemented in the backend system of [ChaturMail: AI Email Generator](https://play.google.com/store/apps/details?id=com.wilfredalmeida.chaturmail)

## Understanding Overall Pipeline Flow

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1672482313295/bcb62eb1-070e-4f8b-9dab-8a4b76ab8bad.png align="center")

1. Code changes are pushed to the master branch on GitHub
    
2. The repo has a Dockerfile. GitHub Actions does the following tasks
    
    * Build Docker Image
        
    * Push the image to Harbor Container Registry
        
    * Update YAML config being watched by ArgoCD
        
3. The [Harbor Container Registry](https://goharbor.io/) is hosted on my VPS, reverse proxied by NGINX, and domain mapped by Cloudflare. The GH action uploads the built image here
    
4. ArgoCD is installed on the VPS and watches a repo of YAML configs for Kubernetes. Any changes to the configs trigger a deployment by ArgoCD. The GH action updates the image tag in the YAML config
    
5. ArgoCD detects the change in YAML and initiates a K8S deployment
    
6. The docker image needed by K8S pods is fetched locally from Harbor
    
7. Kubernetes deploys and manages the pods w.r.t. to restarting, respawning, and load balancing
    

## Role of NGINX

[NGINX](https://www.nginx.com/) acts as a gateway to the VPS. All services are exposed to the internet utilizing NGINX. In the pipeline, NGINX plays the following roles:

* Reverse proxies Harbor
    
* Reverse proxies ChaturMail backend
    

## Application Exposure

The backend system for ChaturMail is served by a Kubernetes load balancer service which gets an internal local-only IP address. This service is then reverse proxied by NGINX.

## Role of Cloudflare

The services and applications exposed by the VPS are all configured to work with subdomains of my main domain [wilfredalmeida.com](https://wilfredalmeida.com/)

The domain is managed by Cloudflare and its IP address is proxied which prevents exposing of the original VPS IP and works in favor of Cloudflare's analytics and security services.