vanshikamunjal665-containerization-theory.github.io

CONTAINERIZATION AND DEVOPS THEORY

22 JANUARY 2026

DOCKER BASIC COMMANDS

Reference Link:
https://upessocs.github.io/#dir=/Lectures/Containerization%20and%20DevOps/Theory/Containerization%20and%20DevOps/Theory/&file=011%20Docker%20basic%20commands.md

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Screenshots of commands

1. Enter wsl

wsl

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2. Check docker version

docker version
docker info

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3. Image Management

• List local images
  sudo docker images

• Show all images
  docker images -a

• Only image IDs
  docker images -q

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4. Pull image from registry

sudo docker pull ubuntu

• specifies version
  sudo docker pull ubuntu:22.04

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5. List all Docker images present on the system

sudo docker images

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6. Creating a new container from Ubuntu image

The container starts and immediately exits

sudo docker run ubuntu

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7. Shows containers

• Show all running containers
  sudo docker ps

• Show all containers (running+stopped+exited)
  sudo docker ps -a

• Show only container IDs
  sudo docker ps -q

• Filter ubuntu related containers
  sudo docker ps -a | grep ubuntu —

8. Creating a new container from Ubuntu image

it= interactive terminal
you are inside ubuntu container

sudo docker run -it ubuntu

now you are inside container

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9. Checking current directory

pwd

Docker containers have their own isolated filesystem / is the root directory of the container
It is NOT connected to your Windows folders by default

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10. Showing linux directories

ls

You are now inside a real Linux environment.

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11. Checking if the container is running (in another terminal)

wsl
sudo docker ps

The container is running

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12. Exiting container

exit

Exiting shell = container stops if no background process.

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13. Again checking if container is running (in another terminal)

sudo docker ps
sudo docker ps -a

The container is stopped.

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14. Removing images

sudo docker images
sudo docker rmi 1b44 (error: The Ubuntu image is still linked to stopped containers, Docker protects images from deletion if containers exist)
sudo docker rmi 1b44 -f (force remove)

sudo docker ps -a (shows all containers (running + stopped), Containers still exist, but their image has been removed, they cannot be restarted properly now)

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15. Start and restart containers

sudo docker ps
sudo docker start 1519b
sudo docker ps -a
sudo docker restart eae3

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