Adding federation support to Discourse

angus · October 6, 2023, 1:54am

Bump @how? Or @aschrijver? A log entry of the 500 error that @silverpill is seeing when sending authenticated requests from his platform would help me address this.

aschrijver · October 6, 2023, 5:24am

I think this requires @how as admin to have a closer look.

silverpill · October 6, 2023, 6:30pm

I made a request to SocialHub actor at 2023-10-06T18:27:04 (UTC).
@angus I can also make request to your testing server, if you have one.

how · October 8, 2023, 4:00pm

Sorry guys, I was traveling and can only go back 24h. Could you reproduce the failing request @silverpill ?

Unless there’s a way to go through the log files, then I can dig it out.

silverpill · October 8, 2023, 6:22pm

I’ve made another one at 2023-10-08T18:21:44Z

aschrijver · December 15, 2023, 9:47am

Check out the newest feature of the Discourse ActivityPub plugin just announced by @angus:

[…] We just merged the PR that allows a Discourse category to follow any actor in the fediverse, including other Discourse categories. Yes, that means you can now federate a category between two (or three, or more) Discourses. There’s a few more PRs in the pipeline as part of this phase, but that was a big one.

The post on Discourse Meta has a video demonstrating the feature:

how · December 15, 2023, 3:03pm

hip hip hip hurray for @angus!

silverpill · December 15, 2023, 4:25pm

I tried it again today and it worked. Also, the delivery of Follow activity was successful (status code 202), but the server didn’t send Accept activity back.

An attempt to read activities from outbox results in 500 Internal Server Error.

cc @angus

angus · December 15, 2023, 4:44pm

If someone could share the logs with me, I’ll see what’s going on with your requests there (@how)

*edit actually, never-mind, I’m setting up the plugin on https://test.pavilion.tech to make it easier for folks to test and for me to collect the logs. Details to follow shortly.

angus · December 15, 2023, 5:16pm

@silverpill I’ve setup announcements@test.pavilion.tech for testing purposes

If you could make your requests there I’ll pick up the logs and take a closer look. Thanks!

silverpill · December 15, 2023, 6:03pm

Awesome! I sent a POST request with Follow activity at 2023-12-15T17:53:30 UTC - no Accept so far.

Outbox endpoint works as expected.

angus · December 16, 2023, 7:54pm

Thanks! That was helpful. Your issue should be resolved once this is merged

github.com/discourse/discourse-activity-pub

FIX: Ensure local objects are resolved locally

discourse:main ← angusmcleod:resolve_local_objects_locally

opened 07:53PM - 16 Dec 23 UTC

angusmcleod

+115 -56

Context: https://socialhub.activitypub.rocks/t/adding-federation-support-to-disc…ourse/2966/31 @pmusaraj The issue reported in the linked topic arises when the external actor uses a local id instead of the full object (what Discourse and Mastodon use). While addressing that I took this opportunity to properly disambiguate object resolution (`resolve`) and object storage (`store`) in the processing (incoming) pipeline.

silverpill · December 16, 2023, 9:25pm

The issue reported in the linked topic arises when the external actor uses an id instead of the full object

Thank you for looking into it! Could you tell me which property it was?

angus · December 16, 2023, 9:46pm

Ah sorry, poorly phrased on my part, it’s the object property. A request was being fired (i.e. the instance sending a request to itself), even though you correctly put the local id of the Category Actor there. I’m glad you raised this. I was surprised I hadn’t already handled that case properly (i.e. id only in the object of a Follow request; my tests assumed an object in object). That’s open source for you; someone will quickly find the big simple issue you overlooked. Thanks again.

angus · December 19, 2023, 1:34pm

@silverpill Just to let you know, this PR has been merged.

github.com/discourse/discourse-activity-pub

FIX: Ensure local objects are resolved locally

discourse:main ← angusmcleod:resolve_local_objects_locally

opened 07:53PM - 16 Dec 23 UTC

angusmcleod

+115 -56

Context: https://socialhub.activitypub.rocks/t/adding-federation-support-to-disc…ourse/2966/31 @pmusaraj The issue reported in the linked topic arises when the external actor uses an id in the `object` instead of the full object. While addressing that I took this opportunity to properly disambiguate object resolution (`resolve`) and object storage (`store`) in the processing (incoming) pipeline.

I’ve just rebuilt test.pavilion.tech so it’s running the latest Discourse and Plugin versions. If you have time to test again that’d be much appreciated!

silverpill · December 19, 2023, 9:45pm

I made some adjustments on my side as well, and now follow-accept sequence is working

silverpill · December 23, 2023, 12:12am

@angus I’m doing more testing, this time with outboxes.

At SocialHub a GET request to outbox results in 500 Internal Server Error. For example this outbox doesn’t work for me: https://socialhub.activitypub.rocks/ap/actor/bcde488169a4ac803695493219aece2a/outbox

The outbox at test.pavilion.tech is working: https://test.pavilion.tech/ap/actor/bfc94e963fef378247b4189820aff273/outbox. I noticed that it contains activities which are usually treated as private, such as Accept, though this might be intentional. It also contains several Create(Note) activities which have Group actor as audience. Are they not Public?

angus · December 23, 2023, 3:33pm

SocialHub may need to update to the latest version.

They should federated with the publication collection in cc, albeit I haven’t tested this with the outbox itself (just direct delivery).

github.com

discourse/discourse-activity-pub/blob/313ac9c0e2e8b8f43324b799056ab0823cf01863/app/models/discourse_activity_pub_activity.rb#L69


      
          def audience
            base_object.ap.object? && base_object.audience
          end
          
          def to
            return nil unless local?
            return audience if audience
            return base_object.ap_id if base_object&.ap.actor?
          end
          
          def cc
            return nil unless local?
            result = []
            result << DiscourseActivityPub::JsonLd.public_collection_id if public?
          
            if base_object&.ap.object?
              reply_to_audience = base_object.reply_to&.audience
              result << reply_to_audience if reply_to_audience && to != reply_to_audience
            end
          
            result.present? ? result : nil

As we’re now at the end of the functionality work to get bi-directional ActivityPub working with Discourse, I’ll soon (early January 2024 at the latest) be publishing both a:

contribution guide, for anyone who wants to contribute to the plugin (PRs are welcome); and
an ActivityPub guide, for anyone who wants to integrate with the plugin. This will include example activity JSON.

There may be some tweaks in the process of doing the later to ensure we’ve crossed Ts dotted Is etc ActivityPub-wise.

I’d also just note that we also recently pushed incoming and outgoing object logging so a site admin can see exactly what objects are being received and being published. SocialHub may want to turn that on for debugging purposes.

@silverpill I’ll have another look at the addressing of activities in the outbox while writing the ActivityPub guide. If you notice anything else like this, or have any suggestions, please let me know.

how · December 23, 2023, 5:33pm

@silverpill I just upgraded the plugin here.

silverpill · December 23, 2023, 10:16pm

Thanks @how, but outbox endpoints still return 500.

It could be related to the problem you reported in another topic: