Support com.docker.compose.project label for unambiguously marking the project

[thediveo]

docker-compose attaches a label com.docker.compose.project to every service container created by it. This allows container diagnosis tools to clearly identify groups of containers belonging to the same composer project, without the need to resort to container name parsing heuristics. It would be beneficial for such tools if nerdctl would support either the existing com.docker.compose.project label or alternatively its own nerdctl/project label.

[fahedouch]

Hi @thediveo ,

we already support attaching labels to containers created by docker-compose

nerdctl/pkg/composer/serviceparser/serviceparser.go

Lines 403 to 409 in cc7dfae

	for k, v := range svc.Labels {
	if v == "" {
	c.RunArgs = append(c.RunArgs, fmt.Sprintf("-l=%s", k))
	} else {
	c.RunArgs = append(c.RunArgs, fmt.Sprintf("-l=%s=%s", k, v))
	}
	}

but we must implement the --filter flag to be able to filter on these containers

I take the ticket :)

[thediveo]

From what I saw using a nerdctl version checked out the date of my issue I could not find any label naming the particular project at the containerd API level. External diagnosis tools need the label at containerd's API level, not at nerdctl's CLI level. Am I overlooking some label here? The label I refer to is automatically attached by docker-compose, but not by nerdctl. Project developers do not need to manually attach these labels themselves, they are never put into a composer project file, as docker-compose attaches them by itself.

[fahedouch]

@thediveo I see what you mean. I added a PR to set this label for the containers when using composer. I will implement the --filter flag later if you will use nerdctlto filter containers from containerd API

[AkihiroSuda]

The label is now set on containers (#250).

TODO: set labels on volumes and networks #258

[thediveo]

Thank you very much!

[AkihiroSuda]

Done in #274