question: cannot delete because running container is using it

[tony-kerz]

love the utility (i almost think the functionality should be built into docker itself).

i'm seeing the following when running (is this normal, should it even be attempting this?):

Error calling remove_image alpine:latest 409 Client Error: Conflict ("Conflict, cannot delete 31f630c65071 because the running container a4241b3e14b6 is using it, stop it and use -f to force")

here are the vitals for the environment:

CoreOS stable (633.1.0)

$ docker version
Client version: 1.5.0
Client API version: 1.17
Go version (client): go1.3.3
Git commit (client): a8a31ef-dirty
OS/Arch (client): linux/amd64
Server version: 1.5.0
Server API version: 1.17
Go version (server): go1.3.3
Git commit (server): a8a31ef-dirty

regards,
tony.

[dnephin]

I've seen this error a lot, so I guess it's normal. I believe it happens when a container is started after dcgc gets a list of containers (which is one of the first things it does), so dcgc thinks an image is not being used. Does that seem possible in your case?

[aripringle]

For what it's worth, I encountered this as well when trying to use dcgc for the first time. I noticed in a dry-run that it wanted to delete two images that were definitely in use by actively running containers. Running it without a the dry-run flag caused it to print the same errors as the OP.

The end result seemed fine (it deleted everything I want, and couldn't delete those two images), but it does appear that something is a little off in the detection of which images are being used.

This was running on an Amazon ECS instance:

docker version
Client:
Version: 1.9.1
API version: 1.21
Go version: go1.4.2
Git commit: a34a1d5/1.9.1
Built:
OS/Arch: linux/amd64

Server:
Version: 1.9.1
API version: 1.21
Go version: go1.4.2
Git commit: a34a1d5/1.9.1
Built:
OS/Arch: linux/amd64