Merge branch 'feature/relay' into 'develop'

message relay

Closes #144

See merge request pleroma/pleroma!264

10 files changed, 198 insertions, 5 deletions

diff --git a/lib/mix/tasks/relay_follow.ex b/lib/mix/tasks/relay_follow.ex
new file mode 100644
index 000000000..ac6f20924
--- /dev/null
+++ b/lib/mix/tasks/relay_follow.ex
@@ -0,0 +1,15 @@
+defmodule Mix.Tasks.RelayFollow do
+  use Mix.Task
+  require Logger
+  alias Pleroma.Web.ActivityPub.Relay
+
+  @shortdoc "Follows a remote relay"
+  def run([target]) do
+    Mix.Task.run("app.start")
+
+    :ok = Relay.follow(target)
+
+    # put this task to sleep to allow the genserver to push out the messages
+    :timer.sleep(500)
+  end
+end
diff --git a/lib/mix/tasks/relay_unfollow.ex b/lib/mix/tasks/relay_unfollow.ex
new file mode 100644
index 000000000..4621ace83
--- /dev/null
+++ b/lib/mix/tasks/relay_unfollow.ex
@@ -0,0 +1,15 @@
+defmodule Mix.Tasks.RelayUnfollow do
+  use Mix.Task
+  require Logger
+  alias Pleroma.Web.ActivityPub.Relay
+
+  @shortdoc "Follows a remote relay"
+  def run([target]) do
+    Mix.Task.run("app.start")
+
+    :ok = Relay.unfollow(target)
+
+    # put this task to sleep to allow the genserver to push out the messages
+    :timer.sleep(500)
+  end
+end
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 7d7f3b23e..88293a4f3 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -77,7 +77,7 @@ defmodule Pleroma.User do
     changes =
       %User{}
       |> cast(params, [:bio, :name, :ap_id, :nickname, :info, :avatar])
-      |> validate_required([:name, :ap_id, :nickname])
+      |> validate_required([:name, :ap_id])
       |> unique_constraint(:nickname)
       |> validate_format(:nickname, @email_regex)
       |> validate_length(:bio, max: 5000)
@@ -516,7 +516,8 @@ defmodule Pleroma.User do
               u.nickname,
               u.name
             )
-        }
+        },
+        where: not is_nil(u.nickname)
       )
 
     q =
@@ -595,7 +596,11 @@ defmodule Pleroma.User do
   end
 
   def local_user_query() do
-    from(u in User, where: u.local == true)
+    from(
+      u in User,
+      where: u.local == true,
+      where: not is_nil(u.nickname)
+    )
   end
 
   def deactivate(%User{} = user) do
@@ -654,6 +659,25 @@ defmodule Pleroma.User do
     end
   end
 
+  def get_or_create_instance_user do
+    relay_uri = "#{Pleroma.Web.Endpoint.url()}/relay"
+
+    if user = get_by_ap_id(relay_uri) do
+      user
+    else
+      changes =
+        %User{}
+        |> cast(%{}, [:ap_id, :nickname, :local])
+        |> put_change(:ap_id, relay_uri)
+        |> put_change(:nickname, nil)
+        |> put_change(:local, true)
+        |> put_change(:follower_address, relay_uri <> "/followers")
+
+      {:ok, user} = Repo.insert(changes)
+      user
+    end
+  end
+
   # AP style
   def public_key_from_info(%{
         "source_data" => %{"publicKey" => %{"publicKeyPem" => public_key_pem}}
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 298d7817a..68b398786 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -572,12 +572,23 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
         "locked" => locked
       },
       avatar: avatar,
-      nickname: "#{data["preferredUsername"]}@#{URI.parse(data["id"]).host}",
       name: data["name"],
       follower_address: data["followers"],
       bio: data["summary"]
     }
 
+    # nickname can be nil because of virtual actors
+    user_data =
+      if data["preferredUsername"] do
+        Map.put(
+          user_data,
+          :nickname,
+          "#{data["preferredUsername"]}@#{URI.parse(data["id"]).host}"
+        )
+      else
+        Map.put(user_data, :nickname, nil)
+      end
+
     {:ok, user_data}
   end
 
diff --git a/lib/pleroma/web/activity_pub/activity_pub_controller.ex b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
index d337532d0..52b2a467e 100644
--- a/lib/pleroma/web/activity_pub/activity_pub_controller.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
@@ -3,6 +3,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
   alias Pleroma.{User, Object}
   alias Pleroma.Web.ActivityPub.{ObjectView, UserView}
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Relay
   alias Pleroma.Web.Federator
 
   require Logger
@@ -107,6 +108,17 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
     json(conn, "ok")
   end
 
+  def relay(conn, params) do
+    with %User{} = user <- Relay.get_actor(),
+         {:ok, user} <- Pleroma.Web.WebFinger.ensure_keys_present(user) do
+      conn
+      |> put_resp_header("content-type", "application/activity+json")
+      |> json(UserView.render("user.json", %{user: user}))
+    else
+      nil -> {:error, :not_found}
+    end
+  end
+
   def errors(conn, {:error, :not_found}) do
     conn
     |> put_status(404)
diff --git a/lib/pleroma/web/activity_pub/relay.ex b/lib/pleroma/web/activity_pub/relay.ex
new file mode 100644
index 000000000..d30853d62
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/relay.ex
@@ -0,0 +1,44 @@
+defmodule Pleroma.Web.ActivityPub.Relay do
+  alias Pleroma.{User, Object, Activity}
+  alias Pleroma.Web.ActivityPub.ActivityPub
+  require Logger
+
+  def get_actor do
+    User.get_or_create_instance_user()
+  end
+
+  def follow(target_instance) do
+    with %User{} = local_user <- get_actor(),
+         %User{} = target_user <- User.get_or_fetch_by_ap_id(target_instance),
+         {:ok, activity} <- ActivityPub.follow(local_user, target_user) do
+      Logger.info("relay: followed instance: #{target_instance}; id=#{activity.data["id"]}")
+    else
+      e -> Logger.error("error: #{inspect(e)}")
+    end
+
+    :ok
+  end
+
+  def unfollow(target_instance) do
+    with %User{} = local_user <- get_actor(),
+         %User{} = target_user <- User.get_or_fetch_by_ap_id(target_instance),
+         {:ok, activity} <- ActivityPub.unfollow(local_user, target_user) do
+      Logger.info("relay: unfollowed instance: #{target_instance}: id=#{activity.data["id"]}")
+    else
+      e -> Logger.error("error: #{inspect(e)}")
+    end
+
+    :ok
+  end
+
+  def publish(%Activity{data: %{"type" => "Create"}} = activity) do
+    with %User{} = user <- get_actor(),
+         %Object{} = object <- Object.normalize(activity.data["object"]["id"]) do
+      ActivityPub.announce(user, object)
+    else
+      e -> Logger.error("error: #{inspect(e)}")
+    end
+  end
+
+  def publish(_), do: nil
+end
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index 7cdc1656b..0664b5a2e 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -306,6 +306,24 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   @doc """
   Make announce activity data for the given actor and object
   """
+  # for relayed messages, we only want to send to subscribers
+  def make_announce_data(
+        %User{ap_id: ap_id, nickname: nil} = user,
+        %Object{data: %{"id" => id}} = object,
+        activity_id
+      ) do
+    data = %{
+      "type" => "Announce",
+      "actor" => ap_id,
+      "object" => id,
+      "to" => [user.follower_address],
+      "cc" => [],
+      "context" => object.data["context"]
+    }
+
+    if activity_id, do: Map.put(data, "id", activity_id), else: data
+  end
+
   def make_announce_data(
         %User{ap_id: ap_id} = user,
         %Object{data: %{"id" => id}} = object,
@@ -360,7 +378,12 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     if activity_id, do: Map.put(data, "id", activity_id), else: data
   end
 
-  def add_announce_to_object(%Activity{data: %{"actor" => actor}}, object) do
+  def add_announce_to_object(
+        %Activity{
+          data: %{"actor" => actor, "cc" => ["https://www.w3.org/ns/activitystreams#Public"]}
+        },
+        object
+      ) do
     announcements =
       if is_list(object.data["announcements"]), do: object.data["announcements"], else: []
 
@@ -369,6 +392,8 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     end
   end
 
+  def add_announce_to_object(_, object), do: {:ok, object}
+
   def remove_announce_from_object(%Activity{data: %{"actor" => actor}}, object) do
     announcements =
       if is_list(object.data["announcements"]), do: object.data["announcements"], else: []
diff --git a/lib/pleroma/web/activity_pub/views/user_view.ex b/lib/pleroma/web/activity_pub/views/user_view.ex
index fc76f2940..16419e1b7 100644
--- a/lib/pleroma/web/activity_pub/views/user_view.ex
+++ b/lib/pleroma/web/activity_pub/views/user_view.ex
@@ -9,6 +9,35 @@ defmodule Pleroma.Web.ActivityPub.UserView do
   alias Pleroma.Web.ActivityPub.Utils
   import Ecto.Query
 
+  # the instance itself is not a Person, but instead an Application
+  def render("user.json", %{user: %{nickname: nil} = user}) do
+    {:ok, user} = WebFinger.ensure_keys_present(user)
+    {:ok, _, public_key} = Salmon.keys_from_pem(user.info["keys"])
+    public_key = :public_key.pem_entry_encode(:SubjectPublicKeyInfo, public_key)
+    public_key = :public_key.pem_encode([public_key])
+
+    %{
+      "@context" => "https://www.w3.org/ns/activitystreams",
+      "id" => user.ap_id,
+      "type" => "Application",
+      "following" => "#{user.ap_id}/following",
+      "followers" => "#{user.ap_id}/followers",
+      "inbox" => "#{user.ap_id}/inbox",
+      "name" => "Pleroma",
+      "summary" => "Virtual actor for Pleroma relay",
+      "url" => user.ap_id,
+      "manuallyApprovesFollowers" => false,
+      "publicKey" => %{
+        "id" => "#{user.ap_id}#main-key",
+        "owner" => user.ap_id,
+        "publicKeyPem" => public_key
+      },
+      "endpoints" => %{
+        "sharedInbox" => "#{Pleroma.Web.Endpoint.url()}/inbox"
+      }
+    }
+  end
+
   def render("user.json", %{user: user}) do
     {:ok, user} = WebFinger.ensure_keys_present(user)
     {:ok, _, public_key} = Salmon.keys_from_pem(user.info["keys"])
diff --git a/lib/pleroma/web/federator/federator.ex b/lib/pleroma/web/federator/federator.ex
index ccefb0bdf..078f3ec11 100644
--- a/lib/pleroma/web/federator/federator.ex
+++ b/lib/pleroma/web/federator/federator.ex
@@ -4,6 +4,7 @@ defmodule Pleroma.Web.Federator do
   alias Pleroma.Activity
   alias Pleroma.Web.{WebFinger, Websub}
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Relay
   alias Pleroma.Web.ActivityPub.Transmogrifier
   alias Pleroma.Web.ActivityPub.Utils
   require Logger
@@ -69,6 +70,11 @@ defmodule Pleroma.Web.Federator do
 
         Logger.info(fn -> "Sending #{activity.data["id"]} out via Salmon" end)
         Pleroma.Web.Salmon.publish(actor, activity)
+
+        if Mix.env() != :test do
+          Logger.info(fn -> "Relaying #{activity.data["id"]} out" end)
+          Pleroma.Web.ActivityPub.Relay.publish(activity)
+        end
       end
 
       Logger.info(fn -> "Sending #{activity.data["id"]} out via AP" end)
diff --git a/lib/pleroma/web/router.ex b/lib/pleroma/web/router.ex
index 68e159f6a..927323794 100644
--- a/lib/pleroma/web/router.ex
+++ b/lib/pleroma/web/router.ex
@@ -5,6 +5,7 @@ defmodule Pleroma.Web.Router do
 
   @instance Application.get_env(:pleroma, :instance)
   @federating Keyword.get(@instance, :federating)
+  @allow_relay Keyword.get(@instance, :allow_relay)
   @public Keyword.get(@instance, :public)
   @registrations_open Keyword.get(@instance, :registrations_open)
 
@@ -293,6 +294,10 @@ defmodule Pleroma.Web.Router do
     get("/externalprofile/show", TwitterAPI.Controller, :external_profile)
   end
 
+  pipeline :ap_relay do
+    plug(:accepts, ["activity+json"])
+  end
+
   pipeline :ostatus do
     plug(:accepts, ["xml", "atom", "html", "activity+json"])
   end
@@ -329,6 +334,13 @@ defmodule Pleroma.Web.Router do
   end
 
   if @federating do
+    if @allow_relay do
+      scope "/relay", Pleroma.Web.ActivityPub do
+        pipe_through(:ap_relay)
+        get("/", ActivityPubController, :relay)
+      end
+    end
+
     scope "/", Pleroma.Web.ActivityPub do
       pipe_through(:activitypub)
       post("/users/:nickname/inbox", ActivityPubController, :inbox)