Add Webfinger

lib/nulla/activitypub.ex

@@ -243,4 +243,17 @@ defmodule Nulla.ActivityPub do
 
     Jason.OrderedObject.new(data)
   end
+
+  def webfinger(domain, username, resource) do
+    Jason.OrderedObject.new(
+      subject: resource,
+      links: [
+        Jason.OrderedObject.new(
+          rel: "self",
+          type: "application/activity+json",
+          href: "https://#{domain}/@#{username}"
+        )
+      ]
+    )
+  end
 end

lib/nulla/models/user.ex

@@ -77,5 +77,7 @@ defmodule Nulla.Models.User do
     ])
   end
 
+  def get_user_by_username(username), do: Repo.get_by(User, username: username)
+
   def get_user_by_username!(username), do: Repo.get_by!(User, username: username)
 end