How can subflows inherit tags

Archive
1

I’m currently using a model where one flow starts several subflows and tasks. I know I can use with tags('x'): pattern to add tags, but I’m not sure how to achieve that these subflows and tasks inherit the top level tags. Is there a way to achieve that?

1 Like
2

What’s your use case for using tags here?

Tags can be set on tasks for concurrency limits

3

We’re trying out prefect in our team that has quite diverse focuses. One of the uses for tags is to allow grouping in UI per sub-team. Another one is to group by domains (one domain comprises several flows, different sub-teams could participate in different domains).
We’re not using it for concurrency.

1 Like
4

Gotcha. In that case, you should set tags on deployments e.g.:

prefect deployment build your_flow.py:flow_name -q yourqueue -t yourtag
5

I do that, this way:

Deployment.build_from_flow(
    flow=latencies.backfill,
    name="latencies-index-backfill",
    parameters={
        "desk": Desk.index,
        "date_ids": date_ids,
    },
    version=1,
    work_queue_name="performance",
    tags=["exchange1", "latencies", "index", "backfill"],
    storage=storage,
    apply=True,
)

But the tags are not propagated to the tasks. Could it be that if I have with tags(...): in the code, all tags defined in the deployment will be removed? If so, then I misunderstood, and with tags(...): is not additive.

6

those tags are set on deployments, not tags, which means that they get applied to flow runs rather than task runs

deployment tags and task tags are very different:

  • deployment tags = used for the organization of projects
  • task tags = used for task-run-level concurrency limits
7

I’m having a similar issue - I have a flow that has several subflows. I add tags to the deployment on the parent flow, but when the subflows run they don’t have the tags applied. Is there a way to have subflows inherit the tags of their parent flow?

8

why would you want to do that? tags are helpful for deployments, they don’t play any role on flows - you can’t even attach tags to flows, only to deployments

9

tags are helpful for deployments, they don’t play any role on flows

I don’t really see it this way because tags are shown in the “Flow Runs” list (and on a flow runs page), so they are related to flows in some way (or specifically a flow run). We use tags on flow runs to indicate how they were created (e.g. “auto-scheduled”, “cloud-function”), but the subflows (which were created the same way) don’t get any tags.

10

I understand why filtering this way could be useful, so worth opening a feature request as a GitHub issue and we can see whether we can add it. do you want to open a GitHub issue?