Merge branch '534_federation_targets_reachability' into 'develop'

[#534] Unreachable federation targets retirement

Closes #534

See merge request pleroma/pleroma!703

10 files changed, 221 insertions, 35 deletions

diff --git a/lib/pleroma/instances.ex b/lib/pleroma/instances.ex
new file mode 100644
index 000000000..5e107f4c9
--- /dev/null
+++ b/lib/pleroma/instances.ex
@@ -0,0 +1,36 @@
+defmodule Pleroma.Instances do
+  @moduledoc "Instances context."
+
+  @adapter Pleroma.Instances.Instance
+
+  defdelegate filter_reachable(urls_or_hosts), to: @adapter
+  defdelegate reachable?(url_or_host), to: @adapter
+  defdelegate set_reachable(url_or_host), to: @adapter
+  defdelegate set_unreachable(url_or_host, unreachable_since \\ nil), to: @adapter
+
+  def set_consistently_unreachable(url_or_host),
+    do: set_unreachable(url_or_host, reachability_datetime_threshold())
+
+  def reachability_datetime_threshold do
+    federation_reachability_timeout_days =
+      Pleroma.Config.get(:instance)[:federation_reachability_timeout_days] || 0
+
+    if federation_reachability_timeout_days > 0 do
+      NaiveDateTime.add(
+        NaiveDateTime.utc_now(),
+        -federation_reachability_timeout_days * 24 * 3600,
+        :second
+      )
+    else
+      ~N[0000-01-01 00:00:00]
+    end
+  end
+
+  def host(url_or_host) when is_binary(url_or_host) do
+    if url_or_host =~ ~r/^http/i do
+      URI.parse(url_or_host).host
+    else
+      url_or_host
+    end
+  end
+end
diff --git a/lib/pleroma/instances/instance.ex b/lib/pleroma/instances/instance.ex
new file mode 100644
index 000000000..a87590d8b
--- /dev/null
+++ b/lib/pleroma/instances/instance.ex
@@ -0,0 +1,102 @@
+defmodule Pleroma.Instances.Instance do
+  @moduledoc "Instance."
+
+  alias Pleroma.Instances
+  alias Pleroma.Instances.Instance
+
+  use Ecto.Schema
+
+  import Ecto.{Query, Changeset}
+
+  alias Pleroma.Repo
+
+  schema "instances" do
+    field(:host, :string)
+    field(:unreachable_since, :naive_datetime)
+
+    timestamps()
+  end
+
+  defdelegate host(url_or_host), to: Instances
+
+  def changeset(struct, params \\ %{}) do
+    struct
+    |> cast(params, [:host, :unreachable_since])
+    |> validate_required([:host])
+    |> unique_constraint(:host)
+  end
+
+  def filter_reachable([]), do: []
+
+  def filter_reachable(urls_or_hosts) when is_list(urls_or_hosts) do
+    hosts =
+      urls_or_hosts
+      |> Enum.map(&(&1 && host(&1)))
+      |> Enum.filter(&(to_string(&1) != ""))
+
+    unreachable_hosts =
+      Repo.all(
+        from(i in Instance,
+          where:
+            i.host in ^hosts and
+              i.unreachable_since <= ^Instances.reachability_datetime_threshold(),
+          select: i.host
+        )
+      )
+
+    Enum.filter(urls_or_hosts, &(&1 && host(&1) not in unreachable_hosts))
+  end
+
+  def reachable?(url_or_host) when is_binary(url_or_host) do
+    !Repo.one(
+      from(i in Instance,
+        where:
+          i.host == ^host(url_or_host) and
+            i.unreachable_since <= ^Instances.reachability_datetime_threshold(),
+        select: true
+      )
+    )
+  end
+
+  def reachable?(_), do: true
+
+  def set_reachable(url_or_host) when is_binary(url_or_host) do
+    with host <- host(url_or_host),
+         %Instance{} = existing_record <- Repo.get_by(Instance, %{host: host}) do
+      {:ok, _instance} =
+        existing_record
+        |> changeset(%{unreachable_since: nil})
+        |> Repo.update()
+    end
+  end
+
+  def set_reachable(_), do: {:error, nil}
+
+  def set_unreachable(url_or_host, unreachable_since \\ nil)
+
+  def set_unreachable(url_or_host, unreachable_since) when is_binary(url_or_host) do
+    unreachable_since = unreachable_since || DateTime.utc_now()
+    host = host(url_or_host)
+    existing_record = Repo.get_by(Instance, %{host: host})
+
+    changes = %{unreachable_since: unreachable_since}
+
+    cond do
+      is_nil(existing_record) ->
+        %Instance{}
+        |> changeset(Map.put(changes, :host, host))
+        |> Repo.insert()
+
+      existing_record.unreachable_since &&
+          NaiveDateTime.compare(existing_record.unreachable_since, unreachable_since) != :gt ->
+        {:ok, existing_record}
+
+      true ->
+        existing_record
+        |> changeset(changes)
+        |> Repo.update()
+    end
+  end
+
+  def set_unreachable(_, _), do: {:error, nil}
+end
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 0199ac9e7..06e8c3f1c 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.ActivityPub.ActivityPub do
-  alias Pleroma.{Activity, Repo, Object, Upload, User, Notification}
+  alias Pleroma.{Activity, Repo, Object, Upload, User, Notification, Instances}
   alias Pleroma.Web.ActivityPub.{Transmogrifier, MRF}
   alias Pleroma.Web.WebFinger
   alias Pleroma.Web.Federator
@@ -734,7 +734,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
   end
 
   def publish(actor, activity) do
-    followers =
+    remote_followers =
       if actor.follower_address in activity.recipients do
         {:ok, followers} = User.get_followers(actor)
         followers |> Enum.filter(&(!&1.local))
@@ -745,13 +745,14 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     public = is_public?(activity)
 
     remote_inboxes =
-      (Pleroma.Web.Salmon.remote_users(activity) ++ followers)
+      (Pleroma.Web.Salmon.remote_users(activity) ++ remote_followers)
       |> Enum.filter(fn user -> User.ap_enabled?(user) end)
       |> Enum.map(fn %{info: %{source_data: data}} ->
         (is_map(data["endpoints"]) && Map.get(data["endpoints"], "sharedInbox")) || data["inbox"]
       end)
       |> Enum.uniq()
       |> Enum.filter(fn inbox -> should_federate?(inbox, public) end)
+      |> Instances.filter_reachable()
 
     {:ok, data} = Transmogrifier.prepare_outgoing(activity.data)
     json = Jason.encode!(data)
@@ -779,15 +780,24 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
         digest: digest
       })
 
-    @httpoison.post(
-      inbox,
-      json,
-      [
-        {"Content-Type", "application/activity+json"},
-        {"signature", signature},
-        {"digest", digest}
-      ]
-    )
+    with {:ok, %{status: code}} when code in 200..299 <-
+           result =
+             @httpoison.post(
+               inbox,
+               json,
+               [
+                 {"Content-Type", "application/activity+json"},
+                 {"signature", signature},
+                 {"digest", digest}
+               ]
+             ) do
+      Instances.set_reachable(inbox)
+      result
+    else
+      {_post_result, response} ->
+        Instances.set_unreachable(inbox)
+        {:error, response}
+    end
   end
 
   # TODO:
diff --git a/lib/pleroma/web/activity_pub/activity_pub_controller.ex b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
index 7eed0a600..4dea6ab83 100644
--- a/lib/pleroma/web/activity_pub/activity_pub_controller.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
@@ -4,6 +4,7 @@
 
 defmodule Pleroma.Web.ActivityPub.ActivityPubController do
   use Pleroma.Web, :controller
+
   alias Pleroma.{Activity, User, Object}
   alias Pleroma.Web.ActivityPub.{ObjectView, UserView}
   alias Pleroma.Web.ActivityPub.ActivityPub
@@ -17,6 +18,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
   action_fallback(:errors)
 
   plug(Pleroma.Web.FederatingPlug when action in [:inbox, :relay])
+  plug(:set_requester_reachable when action in [:inbox])
   plug(:relay_active? when action in [:relay])
 
   def relay_active?(conn, _) do
@@ -289,4 +291,13 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
     |> put_status(500)
     |> json("error")
   end
+
+  defp set_requester_reachable(%Plug.Conn{} = conn, _) do
+    with actor <- conn.params["actor"],
+         true <- is_binary(actor) do
+      Pleroma.Instances.set_reachable(actor)
+    end
+
+    conn
+  end
 end
diff --git a/lib/pleroma/web/federator/federator.ex b/lib/pleroma/web/federator/federator.ex
index f3a0e18b8..46f7a4973 100644
--- a/lib/pleroma/web/federator/federator.ex
+++ b/lib/pleroma/web/federator/federator.ex
@@ -6,7 +6,7 @@ defmodule Pleroma.Web.Federator do
   use GenServer
   alias Pleroma.User
   alias Pleroma.Activity
-  alias Pleroma.Web.{WebFinger, Websub}
+  alias Pleroma.Web.{WebFinger, Websub, Salmon}
   alias Pleroma.Web.Federator.RetryQueue
   alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Relay
@@ -124,6 +124,10 @@ defmodule Pleroma.Web.Federator do
     end
   end
 
+  def handle(:publish_single_salmon, {user_or_url, feed, poster}) do
+    Salmon.send_to_user(user_or_url, feed, poster)
+  end
+
   def handle(:publish_single_ap, params) do
     case ActivityPub.publish_one(params) do
       {:ok, _} ->
diff --git a/lib/pleroma/web/ostatus/ostatus.ex b/lib/pleroma/web/ostatus/ostatus.ex
index a3155b79d..a20ca17bb 100644
--- a/lib/pleroma/web/ostatus/ostatus.ex
+++ b/lib/pleroma/web/ostatus/ostatus.ex
@@ -48,6 +48,9 @@ defmodule Pleroma.Web.OStatus do
 
   def handle_incoming(xml_string) do
     with doc when doc != :error <- parse_document(xml_string) do
+      with {:ok, actor_user} <- find_make_or_update_user(doc),
+           do: Pleroma.Instances.set_reachable(actor_user.ap_id)
+
       entries = :xmerl_xpath.string('//entry', doc)
 
       activities =
diff --git a/lib/pleroma/web/ostatus/ostatus_controller.ex b/lib/pleroma/web/ostatus/ostatus_controller.ex
index 297aca2f9..302ff38a4 100644
--- a/lib/pleroma/web/ostatus/ostatus_controller.ex
+++ b/lib/pleroma/web/ostatus/ostatus_controller.ex
@@ -14,6 +14,7 @@ defmodule Pleroma.Web.OStatus.OStatusController do
   alias Pleroma.Web.ActivityPub.ActivityPub
 
   plug(Pleroma.Web.FederatingPlug when action in [:salmon_incoming])
+
   action_fallback(:errors)
 
   def feed_redirect(conn, %{"nickname" => nickname}) do
diff --git a/lib/pleroma/web/salmon/salmon.ex b/lib/pleroma/web/salmon/salmon.ex
index e41657da1..07ca42a5f 100644
--- a/lib/pleroma/web/salmon/salmon.ex
+++ b/lib/pleroma/web/salmon/salmon.ex
@@ -6,6 +6,7 @@ defmodule Pleroma.Web.Salmon do
   @httpoison Application.get_env(:pleroma, :httpoison)
 
   use Bitwise
+  alias Pleroma.Instances
   alias Pleroma.Web.XML
   alias Pleroma.Web.OStatus.ActivityRepresenter
   alias Pleroma.User
@@ -163,23 +164,28 @@ defmodule Pleroma.Web.Salmon do
 
   # push an activity to remote accounts
   #
-  defp send_to_user(%{info: %{salmon: salmon}}, feed, poster),
+  def send_to_user(%{info: %{salmon: salmon}}, feed, poster),
     do: send_to_user(salmon, feed, poster)
 
-  defp send_to_user(url, feed, poster) when is_binary(url) do
-    with {:ok, %{status: code}} <-
+  def send_to_user(url, feed, poster) when is_binary(url) do
+    with {:ok, %{status: code}} when code in 200..299 <-
            poster.(
              url,
              feed,
              [{"Content-Type", "application/magic-envelope+xml"}]
            ) do
+      Instances.set_reachable(url)
       Logger.debug(fn -> "Pushed to #{url}, code #{code}" end)
+      :ok
     else
-      e -> Logger.debug(fn -> "Pushing Salmon to #{url} failed, #{inspect(e)}" end)
+      e ->
+        Instances.set_unreachable(url)
+        Logger.debug(fn -> "Pushing Salmon to #{url} failed, #{inspect(e)}" end)
+        :error
     end
   end
 
-  defp send_to_user(_, _, _), do: nil
+  def send_to_user(_, _, _), do: :noop
 
   @supported_activities [
     "Create",
@@ -209,12 +215,16 @@ defmodule Pleroma.Web.Salmon do
       {:ok, private, _} = keys_from_pem(keys)
       {:ok, feed} = encode(private, feed)
 
-      remote_users(activity)
+      remote_users = remote_users(activity)
+
+      salmon_urls = Enum.map(remote_users, & &1.info.salmon)
+      reachable_salmon_urls = Instances.filter_reachable(salmon_urls)
+
+      remote_users
+      |> Enum.filter(&(&1.info.salmon in reachable_salmon_urls))
       |> Enum.each(fn remote_user ->
-        Task.start(fn ->
-          Logger.debug(fn -> "Sending Salmon to #{remote_user.ap_id}" end)
-          send_to_user(remote_user, feed, poster)
-        end)
+        Logger.debug(fn -> "Sending Salmon to #{remote_user.ap_id}" end)
+        Pleroma.Web.Federator.enqueue(:publish_single_salmon, {remote_user, feed, poster})
       end)
     end
   end
diff --git a/lib/pleroma/web/websub/websub.ex b/lib/pleroma/web/websub/websub.ex
index 7ca62c83b..8f7d53b03 100644
--- a/lib/pleroma/web/websub/websub.ex
+++ b/lib/pleroma/web/websub/websub.ex
@@ -5,6 +5,7 @@
 defmodule Pleroma.Web.Websub do
   alias Ecto.Changeset
   alias Pleroma.Repo
+  alias Pleroma.Instances
   alias Pleroma.Web.Websub.{WebsubServerSubscription, WebsubClientSubscription}
   alias Pleroma.Web.OStatus.FeedRepresenter
   alias Pleroma.Web.{XML, Endpoint, OStatus}
@@ -53,23 +54,27 @@ defmodule Pleroma.Web.Websub do
   ]
   def publish(topic, user, %{data: %{"type" => type}} = activity)
       when type in @supported_activities do
-    # TODO: Only send to still valid subscriptions.
+    response =
+      user
+      |> FeedRepresenter.to_simple_form([activity], [user])
+      |> :xmerl.export_simple(:xmerl_xml)
+      |> to_string
+
     query =
       from(
         sub in WebsubServerSubscription,
         where: sub.topic == ^topic and sub.state == "active",
-        where: fragment("? > NOW()", sub.valid_until)
+        where: fragment("? > (NOW() at time zone 'UTC')", sub.valid_until)
       )
 
     subscriptions = Repo.all(query)
 
-    Enum.each(subscriptions, fn sub ->
-      response =
-        user
-        |> FeedRepresenter.to_simple_form([activity], [user])
-        |> :xmerl.export_simple(:xmerl_xml)
-        |> to_string
+    callbacks = Enum.map(subscriptions, & &1.callback)
+    reachable_callbacks = Instances.filter_reachable(callbacks)
 
+    subscriptions
+    |> Enum.filter(&(&1.callback in reachable_callbacks))
+    |> Enum.each(fn sub ->
       data = %{
         xml: response,
         topic: topic,
@@ -267,7 +272,7 @@ defmodule Pleroma.Web.Websub do
     signature = sign(secret || "", xml)
     Logger.info(fn -> "Pushing #{topic} to #{callback}" end)
 
-    with {:ok, %{status: code}} <-
+    with {:ok, %{status: code}} when code in 200..299 <-
            @httpoison.post(
              callback,
              xml,
@@ -276,12 +281,14 @@ defmodule Pleroma.Web.Websub do
                {"X-Hub-Signature", "sha1=#{signature}"}
              ]
            ) do
+      Instances.set_reachable(callback)
       Logger.info(fn -> "Pushed to #{callback}, code #{code}" end)
       {:ok, code}
     else
-      e ->
-        Logger.debug(fn -> "Couldn't push to #{callback}, #{inspect(e)}" end)
-        {:error, e}
+      {_post_result, response} ->
+        Instances.set_unreachable(callback)
+        Logger.debug(fn -> "Couldn't push to #{callback}, #{inspect(response)}" end)
+        {:error, response}
     end
   end
 end
diff --git a/lib/pleroma/web/websub/websub_controller.ex b/lib/pleroma/web/websub/websub_controller.ex
index e58f144e5..a92dfe87b 100644
--- a/lib/pleroma/web/websub/websub_controller.ex
+++ b/lib/pleroma/web/websub/websub_controller.ex
@@ -4,9 +4,11 @@
 
 defmodule Pleroma.Web.Websub.WebsubController do
   use Pleroma.Web, :controller
+
   alias Pleroma.{Repo, User}
   alias Pleroma.Web.{Websub, Federator}
   alias Pleroma.Web.Websub.WebsubClientSubscription
+
   require Logger
 
   plug(