Forget the myth that Docker is only for DevOps. Today, it’s a must-have tool for any developer — as essential as Git or VS Code. Docker lets your code run consistently on every machine — local, staging, or production. No more “works on my machine” nightmares.

This article is a practical cheatsheet of commands — not theory. Whether you’re just getting into containerization or looking for a solid reference, this is your fast track.

🧱 Images

Images are templates that contain your app and everything it needs to run.

  • List all images:
    docker images or docker image ls

  • Pull an image:
    docker pull redis:7-alpine

  • Remove an image:
    docker rmi redis:7-alpine

  • Prune dangling images:
    docker image prune or docker image prune -a

  • Inspect image history:
    docker history <image>

  • Inspect full image info (JSON):
    docker inspect <image>

📦 Containers

Containers are running instances of images — isolated environments where your app runs.

  • List running containers:
    docker ps

  • List all containers (incl. stopped):
    docker ps -a

  • Run a container:

bash
docker run -d -p 8080:80 --name my_nginx nginx
docker run --rm -it ubuntu /bin/bash
docker run -v $(pwd):/app node:18-alpine

Key flags:

  • -d: Detached mode (background)

  • -p: Port mapping

  • -v: Volume mount

  • --name: Custom container name

  • --rm: Remove on exit

  • -it: Interactive terminal

  • -e: Set environment variable

  • --network: Attach to network

  • Start/stop/restart containers:
    docker start/stop/restart <name>

  • Remove container:
    docker rm -f <name> or docker container prune

  • View logs:
    docker logs -f --tail 50 <name>

  • Execute inside a container:
    docker exec -it <name> /bin/bash

  • Copy files:
    From host to container:
    docker cp ./local/file.txt container:/app/
    From container to host:
    docker cp container:/app/file.txt ./

  • Inspect container info:
    docker inspect <container>

🏗️ Build with Dockerfile

bash
docker build -t my_app:1.0 .
docker build --platform linux/amd64 -t my_app_amd64 .

Useful flags:

  • -t: Tag the image
  • -f: Specify Dockerfile path
  • --no-cache: Disable layer caching
  • --build-arg: Pass build-time variables

🧩 Docker Compose

Define multi-container setups in docker-compose.yml.

  • Run and build services:
    docker-compose up -d --build

  • Stop and remove everything:
    docker-compose down -v

  • View container logs:
    docker-compose logs -f <service>

  • Execute inside a service container:
    docker-compose exec db psql -U user -d database

  • Other helpful commands:

    • docker-compose ps
    • docker-compose build
    • docker-compose pull
    • docker-compose restart
    • docker-compose stop/start

🌐 Networks

Docker lets containers communicate over custom networks.

bash
docker network ls
docker network create my_net
docker network inspect my_net
docker network connect my_net my_container
docker network disconnect my_net my_container

💾 Volumes

Volumes persist data across container restarts.

bash
docker volume ls
docker volume create data_store
docker volume inspect data_store
docker volume rm data_store
docker volume prune

✅ Best Practices for Devs

  • Use .dockerignore to reduce image size and cache misses.
  • Optimize layer order in Dockerfile for caching.
  • Use multi-stage builds for lean production images.
  • Avoid running as root unless needed.
  • Clean up regularly: docker system prune -af.
  • Add aliases to save time:
    alias dps='docker ps -a'
    alias dlogs='docker-compose logs -f'

📌 Summary

This cheatsheet gives you everything you need to start using Docker like a pro — no fluff, just the commands that matter.

Start small. Build habits. And soon these will be second nature.