Essential Docker Commands with Examples

Docker Image Commands

🔹 docker pull – Download an Image

Pulls an image from Docker Hub.

docker pull nginx

This downloads the official nginx image locally.

docker images – List Images

docker images

Shows all images available on your system.

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🔹 docker rmi – Remove an Image

docker rmi nginx

Deletes the image if no container is using it.

Docker Container Commands

🔹 docker run – Create & Start a Container

docker run nginx

This command:

1. Pulls the image (if not present)

2. Creates a container

3. Starts it

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🔹 Run Container in Detached Mode

docker run -d nginx

Runs the container in the background.

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🔹 Run Container with Port Mapping

docker run -d -p 8080:80 nginx

Access nginx in browser:

http://localhost:8080

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📋 Container Management Commands

🔹 docker ps – List Running Containers

docker ps

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🔹 List All Containers (Including Stopped)

docker ps -a

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🔹 docker stop – Stop a Container

docker stop <container_id>

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🔹 docker start – Start a Stopped Container

docker start <container_id>

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🔹 docker restart – Restart a Container

docker restart <container_id>

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🔹 docker rm – Remove a Container

docker rm <container_id>

To force remove:

docker rm -f <container_id>

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🔍 Inspecting Containers

🔹 docker logs – View Container Logs

docker logs <container_id>

Very useful for debugging application issues.

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🔹 docker exec – Access Running Container

docker exec -it <container_id> /bin/bash

Now you’re inside the container.

Exit:

exit

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🔹 docker inspect – Detailed Container Info

docker inspect <container_id>

Shows:

• IP address

• Volumes

• Network details

• Configuration

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🧹 Cleanup Commands (Very Important)

🔹 Remove All Stopped Containers

docker container prune

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🔹 Remove Unused Images

docker image prune

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🔹 Remove Everything (Danger ⚠️)

docker system prune -a

Deletes:

• All stopped containers

• Unused images

• Networks

• Cache

👉 Use carefully.

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🧠 Understanding Container Lifecycle

A Docker container goes through these stages:

Created → Running → Stopped → Deleted

Commands mapping:

• Create & start → docker run

• Stop → docker stop

• Start again → docker start

• Delete → docker rm

Understanding this lifecycle helps in troubleshooting.

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🌍 Real DevOps Scenario

Run a Temporary Debug Container

docker run -it ubuntu /bin/bash

Use cases:

• Debug networking

• Test commands

• Check OS behavior

Exit → container stops automatically.

Must-Know Commands Summary

Conclusion

Docker commands are the foundation of container management.
Once you’re comfortable with these commands, Docker stops feeling complex and starts feeling powerful.