Disable Cache for a Module's Function

[coral elm]

Hey 👋

I'm currently writing a module to interact with GitHub and facing some issues with the caching.

Basically I'd like to check if a PR is merged or not. So I've written a function that looks like this:

func (m *Github) IsMerged(ctx context.Context, owner, repo string, number int) (bool, error) {
    client := github.NewClient(nil).WithAuthToken(m.Token)
    ok, _, err := client.PullRequests.IsMerged(ctx, owner, repo, number)
    return ok, err
}

I can then call the function from another module like so: dag.Github().IsMerged("dagger", "dagger", 1)
This works very well.

However, the caching is causing issues when I try to implement logic like waiting until the PR is merged.
In my consumer module, if I call the IsMerged function multiple times in a row then I always get a cache hit to the first call.
This makes logic such as while not IsMerged; sleep 5 and means that I cannot trust the output of IsMerged since it might be cached from a long time ago.

Is there a way I can flag a function so that it is never cached?

Otherwise I think I'd have to add a cachebuster parameter to make each call signature unique?

Thanks for your help!

[hearty vessel]

Hey Vincent!

At the moment the only mechanism for invalidating the cache would be to use a parameter like you say and change its value each time. You can make the parameter optional in case you are also calling this function from the CLI or other places!

[coral elm]

It would be great if we could annotate functions so the codegen takes care of this and we don't have to trust the user 🙂
e.g.

// +cache=false
func (m *Github) IsMerged(...) (bool, error) {

[feral garnet]

that's a good question.Aside from the DX details, I'm wondering if there's a good enough stopgap as a way to avoid dagql caching these types of queries without having to assign a random function argument each time. cc @ripe path?

[ripe path]

user defined functions aren't cached at the moment, so you shouldn't need any sort of annotation - at least, not yet: https://github.com/dagger/dagger/issues/7428

[feral garnet]

oh nice! I forgot about that issue yes. So @coral elm, if you add a cache buster in your IsMerged dagger specific code, that should be able to achieve what you need 🙏

[coral elm]

Yup I've ended up create another function WaitUntilMerged in the same module where there is no caching. However users of my module might still have the issue so I added the optional cachebuster parameter.
Would love a generic solution like shown in the issue with // +cache=false and // +ttl=10s!

[feral garnet]

well.. is there a reason to get any caching at all in that function? why not always invalidating the cache?

for the IsMerged I mean..

having said that, the WaitUntilMerged helper also seems handy