Force uniqueness with previews and logos on the fediverse. Closes #1777 and closes #1776

activitypub/apmodels/actor.go

@@ -161,8 +161,10 @@ func MakeServiceForAccount(accountName string) vocab.ActivityStreamsService {
 	// Profile properties
 
 	// Avatar
+	uniquenessString := data.GetLogoUniquenessString()
 	userAvatarURLString := data.GetServerURL() + "/logo/external"
 	userAvatarURL, err := url.Parse(userAvatarURLString)
+	userAvatarURL.RawQuery = "uc=" + uniquenessString
 	if err != nil {
 		log.Errorln("unable to parse user avatar url", userAvatarURLString, err)
 	}

activitypub/apmodels/actor_test.go

@@ -159,7 +159,12 @@ func TestMakeServiceForAccount(t *testing.T) {
 	}
 
 	expectedAvatar := "https://my.cool.site.biz/logo/external"
-	if person.GetActivityStreamsIcon().At(0).GetActivityStreamsImage().GetActivityStreamsUrl().Begin().GetIRI().String() != expectedAvatar {
+	u, err := url.Parse(person.GetActivityStreamsIcon().At(0).GetActivityStreamsImage().GetActivityStreamsUrl().Begin().GetIRI().String())
+	if err != nil {
+		t.Error(err)
+	}
+	u.RawQuery = ""
+	if u.String() != expectedAvatar {
 		t.Errorf("actor.Avatar = %v, want %v", person.GetActivityStreamsIcon().At(0).GetActivityStreamsImage().GetActivityStreamsUrl().Begin().GetIRI().String(), expectedAvatar)
 	}
 

activitypub/outbox/outbox.go

@@ -69,7 +69,7 @@ func SendLive() error {
 		var imageToAttach string
 		previewGif := filepath.Join(config.WebRoot, "preview.gif")
 		thumbnailJpg := filepath.Join(config.WebRoot, "thumbnail.jpg")
-
+		uniquenessString := shortid.MustGenerate()
 		if utils.DoesFileExists(previewGif) {
 			imageToAttach = "preview.gif"
 		} else if utils.DoesFileExists(thumbnailJpg) {
@@ -77,6 +77,7 @@ func SendLive() error {
 		}
 		if imageToAttach != "" {
 			previewURL.Path = imageToAttach
+			previewURL.RawQuery = "us=" + uniquenessString
 			apmodels.AddImageAttachmentToNote(note, previewURL.String())
 		}
 	}

controllers/admin/config.go

@@ -19,6 +19,7 @@ import (
 	"github.com/owncast/owncast/models"
 	"github.com/owncast/owncast/utils"
 	log "github.com/sirupsen/logrus"
+	"github.com/teris-io/shortid"
 )
 
 // ConfigValue is a container object that holds a value, is encoded, and saved to the database.
@@ -242,7 +243,7 @@ func SetLogo(w http.ResponseWriter, r *http.Request) {
 	}
 
 	imgPath := filepath.Join("data", "logo"+extension)
-	if err := os.WriteFile(imgPath, bytes, 0600); err != nil {
+	if err := os.WriteFile(imgPath, bytes, 0o600); err != nil {
 		controllers.WriteSimpleResponse(w, false, err.Error())
 		return
 	}
@@ -252,6 +253,10 @@ func SetLogo(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if err := data.SetLogoUniquenessString(shortid.MustGenerate()); err != nil {
+		log.Error("Error saving logo uniqueness string: ", err)
+	}
+
 	// Update Fediverse followers about this change.
 	if err := outbox.UpdateFollowersWithAccountUpdates(); err != nil {
 		controllers.WriteSimpleResponse(w, false, err.Error())

core/data/config.go

@@ -18,6 +18,7 @@ const (
 	streamTitleKey                  = "stream_title"
 	streamKeyKey                    = "stream_key"
 	logoPathKey                     = "logo_path"
+	logoUniquenessKey               = "logo_uniqueness"
 	serverSummaryKey                = "server_summary"
 	serverWelcomeMessageKey         = "server_welcome_message"
 	serverNameKey                   = "server_name"
@@ -125,6 +126,22 @@ func SetLogoPath(logo string) error {
 	return _datastore.SetString(logoPathKey, logo)
 }
 
+// SetLogoUniquenessString will set the logo cache busting string.
+func SetLogoUniquenessString(uniqueness string) error {
+	return _datastore.SetString(logoUniquenessKey, uniqueness)
+}
+
+// GetLogoUniquenessString will return the logo cache busting string.
+func GetLogoUniquenessString() string {
+	uniqueness, err := _datastore.GetString(logoUniquenessKey)
+	if err != nil {
+		log.Traceln(logoUniquenessKey, err)
+		return ""
+	}
+
+	return uniqueness
+}
+
 // GetServerSummary will return the server summary text.
 func GetServerSummary() string {
 	summary, err := _datastore.GetString(serverSummaryKey)