Add shared inbox support for ActivityPub delivery (#4755)

* feat(ap): add support for shared inboxes to reduce outbound load

* feat(db): refactor ap followers db into followers repository

* fix(ap): use the updated activity library to pull out the shared inbox endpoint

* chore(deps): point at updated build of owncast/activity

* fix(ap): typeless endpoints

* feat(test): update ActivityPub test to support shared inboxes

* chore(test): remove unused variable

* fix: feedback from review. Guard against SSRF/non-HTTPS/local and handle transaction errors

activitypub/activitypub.go

@@ -5,6 +5,7 @@ import (
 	"github.com/owncast/owncast/activitypub/inbox"
 	"github.com/owncast/owncast/activitypub/outbox"
 	"github.com/owncast/owncast/activitypub/persistence"
+	"github.com/owncast/owncast/activitypub/persistence/followersrepository"
 	"github.com/owncast/owncast/activitypub/workerpool"
 	"github.com/owncast/owncast/persistence/configrepository"
 
@@ -42,8 +43,9 @@ func getOutboundWorkerPoolSize() int {
 		defaultWorkers = 20 // Default for most instances
 	)
 
+	followersRepo := followersrepository.Get()
 	var followerCount int64
-	fc, err := persistence.GetFollowerCount()
+	fc, err := followersRepo.GetCount()
 	if err != nil {
 		log.Errorln("Unable to get follower count", err)
 		return defaultWorkers
@@ -58,7 +60,7 @@ func getOutboundWorkerPoolSize() int {
 		workers = maxWorkers
 	}
 
-	log.Infof("Initializing ActivityPub outbound worker pool with %d workers for %d followers", workers, followerCount)
+	log.Debugf("Initializing ActivityPub outbound worker pool with %d workers for %d followers", workers, followerCount)
 	return workers
 }
 
@@ -79,10 +81,12 @@ func SendDirectFederatedMessage(message, account string) error {
 
 // GetFollowerCount will return the local tracked follower count.
 func GetFollowerCount() (int64, error) {
-	return persistence.GetFollowerCount()
+	followersRepo := followersrepository.Get()
+	return followersRepo.GetCount()
 }
 
 // GetPendingFollowRequests will return the pending follow requests.
 func GetPendingFollowRequests() ([]models.Follower, error) {
-	return persistence.GetPendingFollowRequests()
+	followersRepo := followersrepository.Get()
+	return followersRepo.GetPendingFollowRequests()
 }