• Start service using an external Mongo replicaset. Just need to provide correct DB URI in .env (or as environment variable).
• Start service using the MongoDB replicaset started with docker-compose.
• Start service and MongoDB using docker-compose.
• Start service and MongoDB using minikube (soon).

Service

Configuration

• Configuration is loaded from environment variables.
• Support for loading from an `.env` file is provided. However the `dotenv` is added as dev dependency making sure that `.env` is not loaded in production as this will be a bad practice.
• Before service is started a strict schema validation is applied on configuration object. This is required to make sure the application is started with a valid configuration, at least from structure point of view.
• There are no configuration defaults. This will enforce creating proper environment variables for all configuration parameters.

    SERVICE_PORT=3000
    SERVICE_HOST=0.0.0.0

    PROJECT_NAME=Startershell
    NODE_ENV=development
    DB=mongodb://mongo0:27017,mongo1:27017,mongo2:27017/startershell?replicaSet=rs0
                                    

Swagger documentation

• Swagger documentation for implemented API is exposed automatically on `/documentation` endpoint.
• This documentation is created automatically using the HapiJs endpoint validation so is up-to-date and automatically updated when API is changed.
• This documentation is exposed automatically only for `development` environments, in `staging` or `production` it will no exposed API documentation.
• Project can be started also using minikube (soon).

Endpoint validation

• All endpoints have a strict validation implementing using JOI.
• This implementation will be automatically described in the Swagger documentation.
• Validation errors details are not exposed in the HTTP response. The validation error reason is only exposed in log.

Logging

• Logging is done using 'hapi-pino', one of the fastest logger available for HapiJs.
• Logger uses a pretty log style only in development environments.

Database

• MongoDB is used for this project. Because I wanted to use transactions I needed to use a Mongo replicaset. The docker-compose provided in this project is creating the required MongoDB replicaset.

Start using docker-compose

Docker

• development environment - Dockerfile.dev. This is using nodemon for automatically reloading the service when changes are made.
• production environment - Dockerfile

    FROM mongo:4.1.13-bionic
    ADD ./bin/replicate.js /replicate.js
    ADD ./bin/setup.sh /setup.sh
    CMD ["sh", "setup.sh"]
                                    

    #!/usr/bin/env sh

    if [ -f /replicated.txt ]; then
        echo "Mongo is already set up"
    else
        echo "Setting up mongo replication and seeding initial data..."
        sleep 10s
        mongo mongo0:27017 replicate.js
        echo "Replication done..."
        # Wait for few seconds until replication takes effect
        touch /replicated.txt
    fi
                                    

                                    rs.initiate( {
                                        _id : "rs0",
                                        members: [
                                            { _id: 0, host: "mongo0:27017", priority: 1 },
                                            { _id: 1, host: "mongo1:27017", priority: 0.5 },
                                            { _id: 2, host: "mongo2:27017", priority: 0.5 },
                                        ]
                                    });
                                    

Docker Compose

• start multiple Mongo nodes
• configure them as a replicaset
• start service

    version: "3"
    services:
      service:
        build:
          context: .
          dockerfile: Dockerfile.dev
        image: service:local
        container_name: service
        env_file:
          - env-variables.env
        ports:
          - 3000:3000
        depends_on:
          - mongo-conf
        volumes:
          - .:/app

      mongo0:
        hostname: mongo0
        container_name: mongo0
        image: mongo
        ports:
          - 27017:27017
        restart: always
        entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
      mongo1:
        hostname: mongo1
        container_name: mongo1
        image: mongo
        ports:
          - 27018:27017
        restart: always
        entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
      mongo2:
        hostname: mongo2
        container_name: mongo2
        image: mongo
        ports:
          - 27019:27017
        restart: always
        entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
      mongo-conf:
        container_name: mongo-conf
        build:
          context: .
          dockerfile: Dockerfile-mongo-conf
        depends_on:
          - mongo0
          - mongo1
          - mongo2
                                    

    docker-compose up --build --scale service=0