Docker Cheatsheet — For Everyday Use

A beginner-friendly guide to the most common Docker commands you'll use daily.

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Start & Stop Containers

Command	What it does
docker compose up	Start all containers
docker compose up -d	Start in background (detached mode)
docker compose down	Stop and remove containers
docker compose restart	Restart all containers
docker compose stop	Stop containers (without removing)
docker compose start	Start already created containers

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Check Status

Command	What it does
docker ps	Show only running containers
docker ps -a	Show all containers (including stopped)
docker images	List all downloaded images
docker system df	Show Docker disk usage
docker inspect <name>	Detailed info about a container

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Logs (Most Useful for Debugging!)

Command	What it does
docker compose logs	Show logs of all containers
docker compose logs -f	Follow/live logs of all containers
docker compose logs -f backend	Live logs of a specific container
docker logs <container_id>	Logs by container ID
docker logs --tail 100 <container_id>	Last 100 lines only

Tip: Use -f flag whenever something breaks — it shows errors in real time.

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Go Inside a Container (like SSH)

docker exec -it <container_name> bash   # Open terminal inside container
docker exec -it <container_name> sh     # Use this if bash doesn't work

Tip: Container name is visible under the NAMES column in docker ps

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Rebuild (When Code Changes Aren't Reflecting)

Command	What it does
docker compose up --build	Rebuild and start
docker compose up --build -d	Rebuild in background
docker compose build	Just rebuild without starting

Tip: If your latest changes aren't showing up, always try --build flag.

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Cleanup Commands

Command	What it does
docker system prune -a	Remove ALL unused containers, images, networks
docker rm -f $(docker ps -aq)	Force remove all containers
docker rmi -f $(docker images -aq)	Remove all images
docker volume prune	Remove unused volumes
docker network prune	Remove unused networks

Warning: prune commands are irreversible. Make sure you don't need the data before running them.

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Emergency Commands (When Nothing Works!)

Command	What it does
sudo docker rmi -f $(sudo docker images -aq)	Force remove ALL images
sudo docker rm -f $(sudo docker ps -aq)	Force remove ALL containers
sudo docker system prune -a --volumes	Remove everything — images, containers, networks & volumes

Warning: These are nuclear options — only use when you want a completely fresh start.

Remove images one by one using Image ID (when bulk remove doesn't work):

sudo docker rmi -f <image_id>

# Example:
sudo docker rmi -f 2a5c65859499
sudo docker rmi -f ea7752e531c9
sudo docker rmi -f 60a93af0bba5

Tip: Get Image IDs from docker images command under the IMAGE ID column.

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Verify Everything is Cleaned Up

docker ps -a      # Should return empty list
docker images     # Should return empty list
docker system df  # Should show 0 usage

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Common Errors & Quick Fixes

Error	Fix
Port already in use	Run docker compose down then up again
Changes not reflecting	Run docker compose up --build
Container keeps restarting	Check logs: docker compose logs -f <name>
No space left on device	Run docker system prune -a
Permission denied	Add sudo before the command

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Quick Reference — Most Used Daily Commands

# Start project
docker compose up -d

# Check what's running
docker ps

# See live logs
docker compose logs -f

# Rebuild after code changes
docker compose up --build -d

# Stop everything
docker compose down

# Clean up everything
docker system prune -a

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Key Concepts (Explained Simply)

Term	Simple Explanation
Image	A blueprint/template for a container (like a class in code)
Container	A running instance of an image (like an object from a class)
Volume	Persistent storage that survives container restarts
Network	Lets containers talk to each other
Docker Compose	A tool to manage multiple containers together using a single file
docker-compose.yml	Config file that defines all your containers and settings

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Made for developers who just need Docker to work Use sudo before any command if you get a permission error on Linux.