How to remove a stubborn docker image

dockervirtualization

I was trying to remove a Docker image as follows and could not figure out how to do this.

List of docker images

$ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED              VIRTUAL SIZE
<none>              <none>              04251cf7a8b9        About a minute ago   356.1 MB
pg-image            latest              1060b3e656b6        5 minutes ago        323.9 MB
redis-image         latest              8df469463da3        14 minutes ago       137.7 MB
ubuntu              12.04               822a01ae9a15        2 weeks ago          108.1 MB

Docker image I'd like to remove:

$ docker rmi 042
Error response from daemon: Conflict, cannot delete 04251cf7a8b9 because 
the container 4ac3a09ab4d3 is using it, use -f to force
2014/08/27 15:16:15 Error: failed to remove one or more images

When I attempted to remove it using -f it was unsuccessful. How do I properly remove this image, and why can I not remove it using docker rmi -f 042?

Best Answer

The issue here is that there's a container, 4ac3a09ab4d3, that's still utilizing this image.

$ docker ps -a
CONTAINER ID        IMAGE                COMMAND                CREATED             STATUS                       PORTS               NAMES
4ac3a09ab4d3        04251cf7a8b9         /bin/sh -c ./git_che   2 minutes ago       Exited (128) 2 minutes ago                       trusting_hawking
02c14db1bc65        pg-image:latest      /usr/lib/postgresql/   5 minutes ago       Up 5 minutes                                     postgres
6a022281382f        redis-image:latest   /usr/bin/redis-serve   8 minutes ago       Up 8 minutes                 6379/tcp            redis-db

You need to remove this container first so that you can remove this image.

# removes container 4ac3a09ab4d3
$ docker rm 4ac

# removes image 04251cf7a8b9
$ docker rmi 042
Deleted: 04251cf7a8b9efd81b8de6fbc0099f12a7933307bd4ecdadbaa9f1672b4a5f8f
Deleted: 7f76b7a22ef2c66a148714980716e7d01d97455b303cbeb7cc371ccba8bb5153
Deleted: bb7221a7b4a01573b0e3a175f3242f5e0ef58371c89a59dec7831146d6102bf8
Deleted: 493a63262d20f2a3ffc050c85d30528ab8a93c9dd2718fdb27dbbaac1a551c06
...

And with that both the container (4ac3a09ab4d3) and image (04251cf7a8b9) have been removed from your system.

Related Solutions

How to remove all the docker images

The simplest way to do this is to use do the following 3 steps:

stop all the containers
remove all the containers
remove all the images

To achieve this you can make use of the docker ps and docker images commands abilities to just return you a list of IDs via there -q or --quiet switch. This gets rid of all the cruft that both these commands typically returns and just gives you a nice list, like so:

Default output

$ docker ps -a
CONTAINER ID        IMAGE                COMMAND                CREATED             STATUS                     PORTS               NAMES
7b055e9e5f1f        fedora:latest        /bin/sh                6 days ago          Exited (0) 6 days ago                          ecstatic_colden        
40da968258eb        fedora:latest        /bin/sh                6 days ago          Exited (127) 6 days ago                        naughty_thompson

Quiet output

$ docker ps -aq
7b055e9e5f1f
40da968258eb
5be4581afad6
4d6c33d4be6d

NOTE: Both docker images and docker ps also make use of the -a or --all switch which shows you all the IDs.

You can utilize this output to construct Docker commands that make use of output from other Docker commands like so:

$ docker rm $(docker ps -qa)

Cleaning house

So to accomplish your task of removing everything you'd use the following commands:

$ docker stop $(docker ps -qa)
$ docker rm $(docker ps -qa)
$ docker rmi $(docker images -qa)

Docker – How to Extract a File from a Docker Image

You can extract files from an image with the following commands:

docker create $image  # returns container ID
docker cp $container_id:$source_path $destination_path
docker rm $container_id

According to the docker create documentation, this doesn't run the container:

The docker create command creates a writeable container layer over the specified image and prepares it for running the specified command. The container ID is then printed to STDOUT. This is similar to docker run -d except the container is never started. You can then use the docker start <container_id> command to start the container at any point.

For reference (my previous answer), a less efficient way of extracting a file from an image is the following:

docker run some_image cat $file_path > $output_path