[TODO] Explore uploading attestations to GitHub as well

[webknjaz]

This is how the official action does this: https://github.com/actions/toolkit/blob/77f247b/packages/attest/src/store.ts#L5-L44.

This is the API endpoint doc: https://docs.github.com/en/rest/repos/repos?apiVersion=2022-11-28#create-an-attestation.

[woodruffw]

Yep, this should be straightforward to do -- the attestation will either need to be uploaded to GH before it's munged into the PEP 740 shape, or re-munged back into a Sigstore bundle for subsequent uploading.

One note: putting things in GH's attestations store also requires attestations: write, which is why I didn't look too closely at it initially for this action -- I didn't want to widen things beyond id-token: write, since that would be painful for users to upgrade to. However, it may be worth it (or something we can feature-test).

[webknjaz]

I haven't found a way to feature-test. So it'd probably be an upload attempt with error suppression...

[woodruffw]

I haven't found a way to feature-test. So it'd probably be an upload attempt with error suppression...

Makes sense to me 🙂

[webknjaz]

@woodruffw it might be a good idea to also explore exposing the signatures to the end-users (maybe, via action outputs?). As in, beyond telling them to scan the dist/ folder for those files. This would let them upload a copy to GH Releases if they want to.

[woodruffw]

Yeah, that's a good idea -- I haven't been 100% sure how to do it since it's a one-many relationship in theory (one dist, potentially multiple attestations), so action outputs become a little hacky. I'll think about that some more.

[webknjaz]

Probably wrap it as a JSON string.

[woodruffw]

Good idea! Outputs are limited to 1MB, but they should be well below that.

[webknjaz]

Yeah, I tend to be wrestling with passing complex data into and out of the actions (like alls-green) for a long time. And I settled on JSON, especially since they have builtin functions available (toJSON()/fromJSON()). The only other option is probably putting things into files.