Docker and docker compose cheat sheet

Docker engine CLI commands

Basic commands

• docker --version: Check Docker version.
• docker ps: List running containers.
• docker ps -a: List all containers (including stopped).
• docker images: List all Docker images.
• docker pull <image>: Download an image from Docker Hub.
• docker run <image>: Run a container from an image.
  • -d: Run in detached mode.
  • -p <host_port>:<container_port>: Map host to container port.
  • --name <name>: Name the container.

Container Management

• docker stop <container>: Stop a running container.
• docker start <container>: Start a stopped container.
• docker restart <container>: Restart a container.
• docker rm <container>: Remove a container.
• docker logs <container>: View logs of a container.
• docker exec -it <container> <command>: Execute a command inside a running container.
  • Example: docker exec -it my_container bash.

Image Management

• docker build -t <tag> .: Build an image from a Dockerfile in the current directory.
• docker tag <image> <repo>:<tag>: Tag an image for a repository.
• docker push <repo>:<tag>: Push an image to a repository.
• docker rmi <image>: Remove an image.

Volume & Network

• docker volume create <name>: Create a volume.
• docker volume ls: List volumes.
• docker network create <name>: Create a network.
• docker network ls: List networks.

System Cleanup

• docker system prune: Remove unused containers, images, networks, and volumes.
• docker image prune: Remove unused images.

Dockerfile

Key instructions:

• FROM: Specify the base image.
  • e.g: FROM image_name:tag
• LABEL: Metadata for the image (e.g., maintainer info).
• WORKDIR: Set the directory for commands like RUN, CMD, ENTRYPOINT.
  • e.g: WORKDIR /app
• COPY: Copies files from host to container.
  • e.g: COPY requirements.txt /app/
• ADD: Similar to COPY, but can also extract archives.
• RUN: Execute commands to install dependencies or configure the container.
  • e.g: RUN apt-get update && apt-get install -y python3
• CMD: Default command to run when the container starts.
  • e.g: CMD ["python3", "app.py"]
• ENTRYPOINT: Similar to CMD, but allows passing additional arguments at runtime.
• EXPOSE: Document the port on which the container listens (doesn't publish the port).
• ENV: provides ability to set env variable inside container.
  • e.g: ENV APP_ENV=production