Docker

Docker is a technology to run containerized applications. Containers package your application with all its dependencies, ensuring it runs the same everywhere.

Essential Commands

View Running Containers

docker ps

To see all containers (including stopped ones):

docker ps -a

Stop Containers

Stop a specific container:

docker stop <container_id>

Stop all running containers:

docker stop $(docker ps -q)

Remove Containers

Remove a stopped container:

docker rm <container_id>

Remove all stopped containers:

docker container prune

View Images

docker images

Remove Images

docker rmi <image_id>

Remove all unused images:

docker image prune -a

Quick Tips

• Use -d flag to run containers in detached (background) mode
• Use --rm to automatically remove the container when it stops
• Use -v to mount volumes for persistent data
• Use --name to give containers memorable names

docker run -d --rm --name my-app -p 8080:80 nginx

This runs nginx in the background, maps port 8080 to container’s port 80, and removes the container automatically when stopped.