Docker Cheatsheet — All Essential Commands for DevOps Engineers

Table of contents

• ⚙️ Install & Setup Docker

• 🐋 Docker Basics

• 📦 Container Management

• 🧱 Image Management

• 🧾 Dockerfile Commands

  • 🔹 Common Dockerfile Instructions

• 📂 Volumes & Data Management

• 🌐 Networking in Docker

• 🧩 Docker Compose

• 🧾 Docker Logs & Inspect

• 🧹 System Cleanup & Info

• ⚡ Bonus: Docker Useful Shortcuts

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Table of Contents

1. Install & Setup Docker

2. Docker Basics

3. Container Management

4. Image Management

5. Dockerfile Commands

6. Volumes & Data Management

7. Networking in Docker

8. Docker Compose

9. Docker Logs & Inspect

10. System Cleanup & Info

11. Bonus: Docker Useful Shortcuts

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⚙️ Install & Setup Docker

# Install Docker on Ubuntu
sudo apt update
sudo apt install docker.io -y

# Start and enable Docker service
sudo systemctl start docker
sudo systemctl enable docker

# Check version
docker --version

# Check Docker service status
sudo systemctl status docker

# Run hello-world container to test
sudo docker run hello-world

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🐋 Docker Basics

docker version              # Show Docker version
docker info                 # Display system-wide information
docker help                 # Show all Docker commands

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📦 Container Management

# Run a new container
docker run -d nginx                         # Run in background
docker run -it ubuntu bash                  # Run interactively
docker run --name myapp -d nginx            # Assign a custom name
docker run -p 8080:80 nginx                 # Map ports (host:container)
docker run -v /host/data:/container/data nginx  # Mount volume
docker run -e VAR=value nginx               # Set environment variable

# List containers
docker ps                                   # List running containers
docker ps -a                                # List all containers

# Container operations
docker stop container_id                    # Stop container
docker start container_id                   # Start stopped container
docker restart container_id                 # Restart container
docker rm container_id                      # Remove container
docker kill container_id                    # Kill running container
docker pause container_id                   # Pause container
docker unpause container_id                 # Resume container
docker rename old_name new_name             # Rename container
docker attach container_id                  # Attach to running container
docker exec -it container_id bash           # Run command inside container
docker logs container_id                    # Show container logs
docker inspect container_id                 # Detailed info about container

# Export & import container
docker export container_id > mycontainer.tar
docker import mycontainer.tar myimage:latest

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🧱 Image Management

# List and pull images
docker images                               # List local images
docker pull nginx                           # Download image
docker search ubuntu                        # Search image from Docker Hub

# Build and tag image
docker build -t myimage:1.0 .               # Build image from Dockerfile
docker tag myimage:1.0 myrepo/myimage:latest  # Tag image

# Remove & clean images
docker rmi image_id                         # Remove image
docker rmi -f image_id                      # Force remove
docker image prune                          # Remove unused images
docker image inspect image_id               # Show image details

# Save & load images
docker save -o nginx.tar nginx:latest       # Save image as tar
docker load -i nginx.tar                    # Load image from tar

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🧾 Dockerfile Commands

Below are the main Dockerfile instructions used to build custom images.

# Dockerfile Example
FROM ubuntu:20.04
MAINTAINER ali_masiu_zama

RUN apt update && apt install -y nginx
COPY index.html /var/www/html/
WORKDIR /app
EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

🔹 Common Dockerfile Instructions

Command	Description
FROM	Base image
MAINTAINER	Author name
RUN	Execute command during build
COPY	Copy files from host to container
ADD	Copy files (with URL/tar support)
WORKDIR	Set working directory
EXPOSE	Expose a port
ENV	Set environment variables
CMD	Define default command
ENTRYPOINT	Define executable command

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📂 Volumes & Data Management

# Create volume
docker volume create myvolume

# List volumes
docker volume ls

# Inspect a volume
docker volume inspect myvolume

# Run container with volume
docker run -d -v myvolume:/data nginx

# Remove unused volumes
docker volume prune

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🌐 Networking in Docker

# List networks
docker network ls

# Inspect network
docker network inspect bridge

# Create custom network
docker network create mynetwork

# Connect/Disconnect container
docker network connect mynetwork container_id
docker network disconnect mynetwork container_id

# Run container in specific network
docker run -d --name app1 --network mynetwork nginx

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🧩 Docker Compose

Use docker-compose.yml to manage multi-container applications.

# Start containers in background
docker-compose up -d

# Stop containers
docker-compose down

# Restart containers
docker-compose restart

# View logs
docker-compose logs -f

# List running services
docker-compose ps

Example docker-compose.yml:

version: '3'
services:
  web:
    image: nginx
    ports:
      - "8080:80"
  db:
    image: mysql
    environment:
      MYSQL_ROOT_PASSWORD: root

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🧾 Docker Logs & Inspect

docker logs container_id            # View logs
docker logs -f container_id         # Follow live logs
docker inspect container_id         # Inspect details
docker events                       # Show real-time Docker events
docker stats                        # Monitor resource usage

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🧹 System Cleanup & Info

docker system df                    # Show disk usage
docker system prune                 # Remove unused containers, networks, images
docker system prune -a              # Remove everything not in use
docker info                         # Display system information
docker version                      # Show Docker version details

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⚡ Bonus: Docker Useful Shortcuts

# Remove all stopped containers
docker rm $(docker ps -aq)

# Remove all unused images
docker rmi $(docker images -q)

# Stop all running containers
docker stop $(docker ps -aq)

# Remove all volumes
docker volume rm $(docker volume ls -q)

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Docker simplifies containerization — and this cheatsheet gives you a one-stop reference to all major Docker commands used by DevOps engineers.

Thank you for reading. Happy Learning 😊!!!