====== Docker - Images - Remove an image ======

===== Find the image =====

<code bash>
docker images
</code>

returns:

<code bash>
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              16.10               df4ba6fcd70e        36 hours ago        100.2 MB
ubuntu              16.04               f753707788c5        36 hours ago        127.2 MB
ubuntu              latest              f753707788c5        36 hours ago        127.2 MB
hello-world         latest              c54a2cc56cbb        3 months ago        1.848 kB
docker/whalesay     latest              6b362a9f73eb        16 months ago       247 MB
</code>

----

===== Remove an image =====

<code bash>
docker rmi image_name
</code>

----

===== Removing images according to a pattern =====

You can find all the images that match a pattern using a combination of **docker images** and **grep**.

Once you're satisfied, you can delete them by using **awk** to pass the IDs to **docker rmi**.

<WRAP info>
**NOTE:**  These utilities are not supplied by Docker and are not necessarily available on all systems:
</WRAP>


To find the images:

<code bash>
docker ps -a |  grep "pattern"
</code>


To remove the images:

<code bash>
docker images | grep "pattern" | awk '{print $1}' | xargs docker rm
</code>

----

===== Remove all images =====

All the Docker images on a system can be listed by adding -a to the **docker images** command.

Once you're sure you want to delete them all, you can add the -q flag to pass the Image ID to **docker rmi**:

To list the images:

<code bash>
docker images -a
</code>


To remove the images:

<code bash>
docker rmi $(docker images -a -q)
</code>

----

===== Remove dangling (unused) images =====

<code bash>
docker rmi $(docker images --filter "dangling=true" -q --no-trunc)
</code>

<WRAP info>
**NOTE:**  The **dangling=true filter** finds unused images.
</WRAP>