Docker and Docker compose example file with commands

Docker is the container managing service that manages the container. The main philosophy of docker is to develop, ship and run anywhere. The docker helps developers/architecture to easily develop applications, ship the applications into the containers that can be deployed everywhere.

Docker example file

Docker file is usually created with the Docker name without any extension. The basic structure of Docker file for Django Project is

    FROM python:3.10-alpine
    ENV PYTHONUNBUFFERED=1

    RUN apk update \
        && apk add --no-cache --virtual .build-deps \
        ca-certificates gcc linux-headers musl-dev \
        libffi-dev jpeg-dev zlib-dev libc-dev python3-dev \
        postgresql-dev cargo
    
    RUN pip install --upgrade pip
    
    # Create group and user
    RUN addgroup group_name && adduser -D user_name -G group_name -h /home/user_name

    ENV HOME /home/user_name
    ENV APP_DIR ${HOME}/project_directory
    WORKDIR ${APP_DIR}
    ADD requirements.txt ${APP_DIR}/
    COPY ./ ${APP_DIR}
    RUN chown -R group_name:group_name ${APP_DIR}
    USER user_name
    RUN pip install -r ${APP_DIR}/requirements.txt
    EXPOSE 8000
    ENTRYPOINT sh -c "python manage.py runserver 0.0.0.0:8000"

Docker file for production to be run with gunicorn

Create a Docker.production file without any file extension

    FROM python:3.10-alpine
    ENV PYTHONUNBUFFERED=1
    
    RUN apk update \
    && apk add --no-cache --virtual .build-deps \
    ca-certificates gcc linux-headers musl-dev \
    libffi-dev jpeg-dev zlib-dev libc-dev python3-dev \
    postgresql-dev cargo
    
    RUN pip install --upgrade pip
    
    # Create group and user
    RUN addgroup group_name && adduser -D user_name -G group_name -h /home/user_name
    
    ENV HOME /home/user_name
    
    ENV APP_DIR ${HOME}/project_name
    
    WORKDIR ${APP_DIR}
    
    ADD requirements.txt ${APP_DIR}/
    
    RUN pip install -r ${APP_DIR}/requirements.txt
    
    COPY ./ ${APP_DIR}
    
    RUN chown -R group_name:group_name ${APP_DIR}
    
    USER user_name
    
    EXPOSE 8000
    
    CMD exec gunicorn config.wsgi:application --bind 0.0.0.0:8000 --workers 3

Docker compose file

Create a docker-compose.yml file.The following docker file consists of redis for caching, and postgres for database

    version: '3.10'
    volumes:
      dbdata:

    networks:
      localhost:
        driver: bridge
      redis-net:
    
    services:
      redis:
        image: redis
        container_name: redis_container
        command: redis-server
        ports:
          - '6380:6379'
        networks:
          - redis-net
      api:
        build:
          context: .
        ports:
          - '8000:8000'
        volumes:
          - .:/home/user_name/project
        env_file: .env
        container_name: unique_container_name
        depends_on:
          - db
        links:
          - db
          - redis
        networks:
          - localhost
          - redis-net
    
      db:
        image: postgres:alpine
        environment:
          - POSTGRES_DB=${DB_NAME}
          - POSTGRES_USER=${DB_USER}
          - POSTGRES_PASSWORD=${DB_PASSWORD}
        container_name: unique_container_name-db
        ports:
          - '5433:5432'
        volumes:
          - dbdata:/var/lib/postgresql
        networks:
          - localhost

Docker compose production file

Create a docker-compose.production.yml file. The following docker file consists of redis service for caching.

    version: '3.10'
    
    networks:
      redis-net:
    
    services:
      redis:
        image: redis
        container_name: redis_container
        command: redis-server
        ports:
          - '6379:6379'
        networks:
          - redis-net
      api:
        build:
          context: .
          dockerfile: Dockerfile.production
        ports:
          - '8000:8000'
        networks:
          - redis-net
        volumes:
          - .:/home/user_name/project_name
        env_file: .env
        container_name: unique_container_name

Command to build a image from Dockerfile

    docker build -f Dockerfile -t ImageName .

This method allows the users to build own Docker images.

Options

• -f: It is used to specify the path to an alternative file to use instead. By default, it looks into the root of the build context.
• -t: is used to mention a tag to the image
• ImageName : This is the name you want to give to your image.
• . : The directory where the Docker File is present.

Builds, (re)creates, starts, and attaches to containers for a service using docker-compose.

    docker-compose -f docker-compose.yml up

Builds, (re)creates, starts, and attaches to containers for a service using docker-compose in detach mode.

    docker-compose -f docker-compose.yml up -d

Or, you can use the following command

    docker-compose -f docker-compose.yml start

Stop the container.

     docker-compose stop

Delete the container with volume.

     docker-compose down --volume

Delete all docker resources (images, containers, volumes, networks).

     docker system prune -a

Run the makemigrations file in the docker

     docker-compose exec api python manage.py makemigrations [options]

Run the migrations file in the docker

     docker-compose exec api python manage.py migrate [options]

Run the commands

     docker-compose exec api python manage.py commands_name