Federate banners out.

lib/pleroma/user.ex

@@ -34,6 +34,13 @@ def avatar_url(user) do
     end
   end
 
+  def banner_url(user) do
+    case user.info["banner"] do
+      %{"url" => [%{"href" => href} | _]} -> href
+      _ -> nil
+    end
+  end
+
   def ap_id(%User{nickname: nickname}) do
     "#{Web.base_url}/users/#{nickname}"
   end

lib/pleroma/web/ostatus/user_representer.ex

@@ -6,6 +6,12 @@ def to_simple_form(user) do
     name = to_charlist(user.name)
     bio = to_charlist(user.bio)
     avatar_url = to_charlist(User.avatar_url(user))
+    banner = if banner_url = User.banner_url(user) do
+      [{:link, [rel: 'header', href: banner_url], []}]
+    else
+      []
+    end
+
     [
       {:id, [ap_id]},
       {:"activity:object", ['http://activitystrea.ms/schema/1.0/person']},
@@ -15,6 +21,6 @@ def to_simple_form(user) do
       {:"poco:note", [bio]},
       {:name, [nickname]},
       {:link, [rel: 'avatar', href: avatar_url], []}
-    ]
+    ] ++ banner
   end
 end