Ability to label workflows and tasks

[flaviuvadan]

Ability to label workflows and tasks

[bobh66]

Great - I need this functionality so I'll push a new PR with these changes. Should it also support annotations? That's the only other metadata attribute that looks like it might be useful at this stage.

[bobh66]

@flaviuvadan Is this as simple as adding a labels attribute to the Task, Workflow and CronWorkflow objects and passing it through to the V1ObjectMeta? I'd be happy to take this as I could really use label support for my application.

[flaviuvadan]

@bobh66 that is correct! The way I think about this is presenting a simple interface to users so they can set an arbitrary mapping labels: Dict[str, str] = {} on a workflow object, which then propagates the labels to the tasks! I'd be excited for your contribution 🙂 and thank you for the other PRs you have submitted thus far!

[dmerrick]

I think it'd be fine if your PR only supported labels for now. The annotation support could come in a future PR (and use your PR as an example)

[bobh66]

I don't see a way to label Tasks as they don't have V1ObjectMeta objects. It appears that we can support labels for Workflows, CronWorkflows and Volumes (the PVC gets the label).

[flaviuvadan]

I don't see a way to label Tasks as they don't have V1ObjectMeta objects. It appears that we can support labels for Workflows, CronWorkflows and Volumes (the PVC gets the label).

The Task template has a field called metadata that takes a V1alpha1Metadata! 🙂 That object has these OpenAPI types on it:

openapi_types = {
    'annotations': 'dict(str, str)',
    'labels': 'dict(str, str)'
}

Perhaps we can instantiate an empty V1alpha1Metadata on the Task and then set the labels on it through the Workflow/CronWorkflow?

[flaviuvadan]

I think it'd be fine if your PR only supported labels for now. The annotation support could come in a future PR (and use your PR as an example)

I will echo what @dmerrick mentioned here 🙂 Let's release these in separate PRs so we (1) keep PRs small (easy to review and add tests for), and (2) incrementally add features (opportunity to write an Issue to for a well-defined use case)!

[bobh66]

OK - I'll work on this as soon as the timezone patch is merged so I don't have a merge conflict with the version file.

Do we want each Task to inherit the labels of the workflow? Or should each Task be able to have it's own labels? I assume the latter. Thanks

[flaviuvadan]

Do we want each Task to inherit the labels of the workflow? Or should each Task be able to have it's own labels? I assume the latter. Thanks

I think the default behavior of Argo is if a workflow specified labels, they are applied to all tasks and tasks have the ability to overwrite those labels. So, I agree with what you mentioned - the latter option seems like the way to go! 🙂