Have tried the following commands, but none of them delete the images.
sudo docker images prune --filter "dangling=true"
sudo docker images prune --all
sudo docker images prune -a
sudo docker images prune
Output for both the commands:
REPOSITORY TAG IMAGE ID CREATED SIZE
Docker version:
$ sudo docker version
Client:
Version: 1.12.6
API version: 1.24
Go version: go1.6.4
Git commit: 78d1802
Built: Tue Jan 10 20:26:30 2017
OS/Arch: linux/amd64
Server:
Version: 1.12.6
API version: 1.24
Go version: go1.6.4
Git commit: 78d1802
Built: Tue Jan 10 20:26:30 2017
OS/Arch: linux/amd64
Docker doc suggests this command, but I encountered error
$ sudo docker image prune -a
docker: 'image' is not a docker command.
See 'docker --help'.`
Looking at the docker image prune and API 1.25 - For Docker Engine 1.13, the API version is 1.25
Remove unused images
The client and daemon API must both be at least 1.25 to use this command. Use the docker version command on the client to check your client and daemon API versions.
And you're running Version: 1.12.6 and API version: 1.24, so you need to update your version to be able to run docker image prune.
If you don't want to (or can't) upgrade you can use docker rmi or docker image rm which don't have a specified API versions, so I expect both to work.