activitypub: c2s: add /api/ap/whoami endpoint for andstatus

lib/pleroma/web/activity_pub/activity_pub_controller.ex

@@ -198,6 +198,14 @@ def relay(conn, _params) do
     end
   end
 
+  def whoami(%{assigns: %{user: %User{} = user}} = conn, _params) do
+    conn
+    |> put_resp_header("content-type", "application/activity+json")
+    |> json(UserView.render("user.json", %{user: user}))
+  end
+
+  def whoami(_conn, _params), do: {:error, :not_found}
+
   def read_inbox(%{assigns: %{user: user}} = conn, %{"nickname" => nickname} = params) do
     if nickname == user.nickname do
       conn

lib/pleroma/web/router.ex

@@ -454,6 +454,7 @@ defmodule Pleroma.Web.Router do
   scope "/", Pleroma.Web.ActivityPub do
     pipe_through([:activitypub_client])
 
+    get("/api/ap/whoami", ActivityPubController, :whoami)
     get("/users/:nickname/inbox", ActivityPubController, :read_inbox)
     post("/users/:nickname/outbox", ActivityPubController, :update_outbox)
   end