DevOps Task - 2

• For backend, I used the resources given in the task pdf.
• I created the service images by separate dockerfile for each service with alpine as base image and installed nodejs and npm to run services.
• The whole setup is dockerised and can be deployed or restarted with latest images by running

bash deploy.sh

Note : deploy.sh script uses docker compose(v2) not docker-compose(v1).

• This application requires Rabbitmq for transmitting messages between containers (i.e. product service and order service) and Redis for temporary db (or cache). Images are pulled automatically during setup.
• To see errors encountered or deployment details during setup, see deploy.log
• I also used nginx reverse proxy for directing requests to containers based on url path.
• Port 3000 is used for listening and accepting requests.

Local setup

• To setup locally without docker, you have to install Rabbitmq and Redis and change the hostname in js files from rabbitmq or redis to localhost.
• Start the Rabbitmq and Redis by

sudo systemctl start [service_name]

• Dependencies can be installed by npm install and service is started by npm start

Usage

• To create new user

curl -X POST http://localhost:3000/users/register -H "Content-Type: application/json" -d '{"name":"test", "email":"test@example.com", "password":"1234"}'

• To login

curl -X POST http://localhost:3000/users/login -H "Content-Type: application/json" -d '{ "email":"test@example.com", "password":"1234"}'

• To see user details

curl -X GET http://localhost:3000/users/profile?name=test

• To delete a user

curl -X DELETE http://localhost:3000/users/profile -H "Content-Type: application/json" -d '{ "email":"test@example.com", "name":"test" }'

• To create new product

curl -X POST http://localhost:3000/product/create -H "Content-Type: application/json" -d '{ "name" : "eraser", "description" : "used to erase", "price" : "10"}'

• To order a product

curl -X POST http://localhost:3000/product/buy -H "Content-Type: application/json" -d '{ "ids" : "669ba919f0b262660130ef58"}'

Output of above requests:

Compose Configuration

• To build the images, Dockerfile is configuration file.
• For running multiple containers at same time as cluster, docker compose is used with compose.yaml as configuration file.
• To persist data of Rabbitmq and Redis, volumes named rabbitmq_db and redis_db is created and mounted at respective directories of containers.
• Since services depend on Rabbitmq and Redis, healthcheck is performed on them to ensure status before starting servcies.

CI/CD Setup and Automated Deployment

• Using Github workflow and actions, Docker images are built and pushed to Dockerhub using docker/build-push-action@v6 action.
• Workflow consists of jobs and job is defined with steps.
• This workflow is triggered whenever there is commit on repo.
• To upload the images, login is needed which is done by docker/login-action@v3 action using PAT(Personal Accesss Token) stored in Github secrets.
• Instead of installing nodejs and npm for each services, they are installed in alpine_node image and it is used for building service images.