docker system prune warn message should display filters if any

[vdemeester]

Description

When running a system prune with filter, the warning message doesn't reflect that the filter will be used.
We should display that the elements pruned will be filtered.

Describe the results you received:

$ docker system prune --filter=label=foo                                                                                                      Tue 30 Jan 2018 03:16:42 PM PST
WARNING! This will remove:
        - all stopped containers
        - all networks not used by at least one container
        - all dangling images
        - all build cache
# […]

Describe the results you expected:

Same message but that acknowledge the filtering.

[adshmh]

@vdemeester Does an output like the following look OK?

$ docker system prune --filter=label=foo
WARNING! This will remove:
        - all stopped containers
        - all networks not used by at least one container
        - all dangling images
        - all build cache

  Elements to be pruned will be filtered with:
      label=foo

[adshmh]

Also it seems that volume, image, and container prune commands do not display the filter either.

[justyntemme]

@vdemeester I have opened a PR to address this request. Please let me know if we would like to implement this any different way.

[olejorgenb]

The merged MR doesn't seem to be in effect anymore? https://github.com/docker/cli/blob/master/cli/command/system/prune.go

It is quite jarring that the warning shouts "ALL" when I've applied a filter.

[thaJeztah]

Filters are printed as part of the template at https://github.com/docker/cli/blob/master/cli/command/system/prune.go#L57

But not all objects (volumes, networks, containers, images) accept the same set of filters

[olejorgenb]

$ docker image prune --all --filter until=240h
WARNING! This will remove all images without at least one container associated to them.
Are you sure you want to continue? [y/N] n
$ docker --version
Docker version 20.10.7, build 20.10.7-0ubuntu5~21.04.2

Shouldn't the filter be displayed here? until is clearly supported by image prune