Essential Docker Commands

Table of Contents

1. Inspection & Monitoring Commands
2. Image Management Commands
3. Execution & Lifecycle Commands
4. Maintenance & Garbage Collection

---

Mastering Docker comes down to understanding a core set of CLI commands. This reference guide breaks down the essential commands every developer needs for inspecting, executing, managing, and maintaining Docker containers and system resources.

1. Inspection & Monitoring Commands

• docker ps Lists active and running containers on your system.

  # List only currently running containers
  docker ps
  
  # List all containers (running, stopped, and exited)
  docker ps -a
  
  # Show only container IDs (useful for scripts/automation)
  docker ps -q
  

  Copy

• docker images Lists all Docker images stored locally on your machine.

  # View all local images with tags and sizes
  docker images
  

  Copy

• docker logs Fetches stdout/stderr logs from a specific container. Critical for debugging background processes.

  # Fetch current logs
  docker logs <container_name_or_id>
  
  # Stream/follow logs in real-time
  docker logs -f <container_name_or_id>
  
  # View the last 50 log entries
  docker logs --tail 50 <container_name_or_id>
  

  Copy

• docker inspect Returns detailed low-level internal configurations and metadata (IP address, volume mounts, network settings, environment variables) in JSON format.

  # Inspect complete container configuration
  docker inspect <container_name_or_id>
  
  # Extract specific metadata using formatting (e.g., retrieve IP address)
  docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' <container_name>
  

  Copy

2. Image Management Commands

• docker pull Downloads a Docker image from a remote registry (like Docker Hub) without instantiating a container.

  # Pull a specific image tag
  docker pull postgres:16-alpine
  

  Copy

• docker rmi Removes one or more local Docker images from your system.

  # Remove an image by tag or ID
  docker rmi postgres:16-alpine
  
  # Force removal of an image in use by a stopped container
  docker rmi -f <image_id>
  

  Copy

3. Execution & Lifecycle Commands

• docker run Creates and starts a new container from an image. Combines docker create and docker start.

  # Common pattern: run detached (-d), named (--name), with port mapping (-p host:container)
  docker run -d --name my-redis -p 6379:6379 redis:alpine
  

  Copy

• docker exec Executes a new command inside an already running container.

  # Open an interactive shell inside a running container
  docker exec -it my-redis sh
  
  # Run a single non-interactive command inside a container
  docker exec my-redis redis-cli ping
  

  Copy

• docker stop Gracefully stops a running container by sending a SIGTERM signal, followed by SIGKILL if it doesn't stop within the timeout period.

  # Stop a running container
  docker stop <container_name_or_id>
  

  Copy

• docker start Starts one or more stopped containers without re-creating them.

  # Restart a previously stopped container
  docker start <container_name_or_id>
  

  Copy

• docker restart Stops and immediately restarts a running or stopped container.

  # Restart a container
  docker restart <container_name_or_id>
  

  Copy

• docker rm Removes stopped containers from disk.

  # Remove a stopped container
  docker rm <container_name_or_id>
  
  # Force remove a currently running container (-f)
  docker rm -f <container_name_or_id>
  

  Copy

4. Maintenance & Garbage Collection

• docker system prune Frees up disk space by removing all stopped containers, unused networks, dangling images, and build caches in one command.

  # Clean up unused Docker resources
  docker system prune
  
  # Comprehensive deep clean (removes all unused images and persistent volumes)
  docker system prune -a --volumes
  

  Copy

Command Summary Quick Reference