Docker : Most useful commands

Docker has a lot to talk about. But I am going to list a few commands here that come handy while working with it on a daily basis. We will list them in a sequence that looks like a tutorial.

1. List all docker containers

docker container ls

2. List all images

docker image ls

docker images

3. Spawn & run from an image, a new container.

docker run image_name COMMAND

Example: docker run -ti ubuntu bash

Note (1) : The tag "latest" is automatically used if no tag is specified.
Note (2) : If the image is not locally available, then it will be downloaded.
Note (3) : To exit from container, press CTRL+D or type 'exit'.

4. Useful arguments with the docker run command

1. -t : Run in a terminal
2. -I : Interactive mode
3. --rm : Run and then, delete this container when it exits.
4. -d : Detached . To run container and leave it running in the background. 

5. See all running containers

docker ps

6. See the last container that was run/exited.

docker ps -l

Note: Containers are not deleted automatically .

7. See all stopped containers list.

 

docker ps -a

8. Commit the changes you made to the container.

docker commit container_id (or NAMES . Get that using docker ps -l command)

Note: This does not change the container specifies her , BUT it creates a new image out of it.
The id of this new IMAGE , is returned to us after the commit.
Run "docker images" to see this new image in the list.

9. Add a tag to an image.

docker tag image_id some_name

10. Commit changes and tag container together.

docker commit container_id image_name

11. Working on a detached container.

docker attach container_id or name

Note: To exit (but not kill . Just leave it again running in the background) , press the key sequence:
Ctrl + p Ctrl + q

12. Run some extra command/process on the running container

 

docker exec

Example: docker exec -ti container_id/name COMMAND

Note: Do the above on a new terminal. You probably are already in the attached state to the same container on a different terminal.

13. Stop a container.

docker container stop container_id

14. Delete/remove a container.

docker container rm container_id

Note: You can also use the Name.

15. Delete an Image

docker image rm <Image Name>

 

16. Remove all unused containers

docker container prune

 

17. See general info about docker and its status on your system

docker info

 

 

18. Docker Volumes. 

We sometimes use volumes to store data. They can accumulate over time. 

 

1. Cleaning volumes
     docker volume prune
   
   
2. Listing volumes
   docker volume list
   
   
3. Inspect the contents of  a volume.
   docker volume inspect newfastapiproj_postgres_data