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Docker Cheat Sheet

Dockerfile examples​

FROM python:3.9
WORKDIR /usr/src/app
COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt
COPY . .
CMD [ "uvicorn", "main:app", "--reload", "--host", "0.0.0.0" ]
FROM node:16
WORKDIR /usr/src/app
COPY package.json ./
RUN npm install
COPY . .
CMD [ "npm", "run", "dev" ]

Build image​

docker build -t nfp-backend .
docker build -t nfp-frontend .

The -t flag tags the image.

Run container​

docker run -p 8000:8000 -it --rm --name nfp-backend-running nfp-backend
docker run -p 3000:3000 -it --rm --name nfp-frontend-running nfp-frontend
  • The -p flag maps the host port to the container port. HOST:CONTAINER
  • The -i and -t flags are commonly used in combination for terminal access. It is shortened to -it.
  • The --rm flag ensures the container is automatically removed after it exits.
  • nfp-backend-running is the name of the running container.
  • nfp-backend is the name of the image.

Bind Mounts​

docker run -p 8000:8000 -it --rm --name nfp-backend-running -v "$PWD":/usr/src/app nfp-backend
docker run -p 3000:3000 -it --rm --name nfp-frontend-running -v "$PWD":/usr/src/app nfp-frontend

The -v "$PWD":/usr/src/app will map your current directory to the /usr/src/app directory in the container. Now, the changes you make will be reflected in the container.

Docker Compose YAML​

version: "3.9"
services:
  backend:
    build: nfp-backend
    ports:
      - 8000:8000
    volumes:
      - ./nfp-backend:/usr/src/app
  frontend:
    build: nfp-frontend
    ports:
      - 3000:3000
    volumes:
      - ./nfp-frontend:/usr/src/app
  db:
    image: postgres:14
    restart: always
    environment:
      POSTGRES_USER: nfp_boilerplate_user
      POSTGRES_DB: nfp_boilerplate_dev
      POSTGRES_PASSWORD: password
    volumes:
      - pgdata:/var/lib/postgresql/data
volumes:
  pgdata:

Note: The named volume is needed to persist data.

Point database host in docker container to local machine​

DATABASE_URL=postgresql://nfp_boilerplate_user:password@host.docker.internal/nfp_boilerplate_dev

This allows the app inside the container to connect to the PostgreSQL instance running on your host machine.

Point database host to another database container​

DATABASE_URL=postgresql://nfp_boilerplate_user:password@db/nfp_boilerplate_dev

List running docker processes.​

docker ps

Open terminal into docker container.​

docker exec -it nfp-boilerplate_backend_1 bash

Shut down docker compose​

docker compose down

Start docker compose​

docker compose up

List volumes​

docker volume ls

Delete everything​

docker stop $(docker ps -aq)
docker rm $(docker ps -aq)
docker network prune -f
docker rmi -f $(docker images --filter dangling=true -qa)
docker volume rm $(docker volume ls --filter dangling=true -q)
docker rmi -f $(docker images -qa)

References​