README.md

Docker usage exercices

cheat-sheet

docker ps: wyświetla listę aktywnych kontenerów.
docker-compose build:
docker-compose up: uruchamia aplikację składającą się z wielu kontenerów.

• Step 1: In folders web and api create Dockerfiles. Please verify whether images can be built and run.

  • Web

  • installs original python 3.9 image python:3.9-slim-buster FROM python:3.9-slim-buster

  • sets workdir for /app

  • copies app.py, templates/index.html, requirements.txt to /app folder

  • installs requirements using pip command

  • exposes port 8000

  • calls python with app.py argument

    Solution

      FROM python:3.9-slim-buster
      WORKDIR /app
      COPY app.py /app
      COPY templates/index.html /app/templates/
      COPY requirements.txt /app
      RUN pip install --no-cache-dir -r requirements.txt 
      EXPOSE 8000
      CMD ["python", "app.py"]
    

  • Api

  • installs original node:14

  • sets workdir for /app

  • copies package.json, index.js to /app folder

  • installs requirements using npm install command

  • exposes port 3000

  • calls node with start argument

    Solution

      FROM node:14
      WORKDIR /app
      COPY package.json /app
      COPY index.js /app
      RUN npm install
      EXPOSE 3000
      CMD ["npm", "start"]
    

• Step 2: In docker-compose folder create docker-compose.yaml.

  • Define default template with two services. In place of variables place correct values matching project files.

    services:
        api:
            build:
                context: ${backend_folder_name}
                dockerfile: Dockerfile
            ports:
                - "${api_host_port}:${api_container_port}"
            networks:
                - default
        web:
            build:
                context: ${web_folder_name}
                dockerfile: Dockerfile
            ports:
                - "${web_host_port}:${web_container_port}"
            networks:
                - default
    

    Solution

      services:
          api:
              build:
                  context: backend
                  dockerfile: Dockerfile
              ports:
                  - "3000:3000"
              networks:
                  - default
          web:
              build:
                  context: web
                  dockerfile: Dockerfile
              ports:
                  - "8000:8000"
              networks:
                  - default
    

  • Build containers with docker-compose matching command and run containers. Verify you can curl api /hello endpoint from your machine and visit frontend. Use localhost:${web_host_port} for frontend and localhost:${api_host_port}/hello for api.

    Solution

      docker-compose build && docker-compose up
    
      You should see output in console like:
      api_1  | 
      api_1  | > [email protected] start /app
      api_1  | > node index.js
      api_1  | 
      api_1  | Server listening on port 3000
      web_1  |  * Serving Flask app 'app'
      web_1  |  * Debug mode: on
      web_1  | WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
      web_1  |  * Running on all addresses (0.0.0.0)
      web_1  |  * Running on http://127.0.0.1:8000
      web_1  |  * Running on http://172.25.0.3:8000
      web_1  | Press CTRL+C to quit
      web_1  |  * Restarting with stat
      web_1  |  * Debugger is active!
      web_1  |  * Debugger PIN: 597-877-487