[#534] Initial implementation of unreachable federation targets retirement.

lib/pleroma/instances.ex

@@ -0,0 +1,12 @@
+defmodule Pleroma.Instances do
+  @moduledoc "Instances context."
+
+  @adapter Pleroma.Instances.Instance
+
+  defdelegate reachable?(url), to: @adapter
+  defdelegate set_reachable(url), to: @adapter
+  defdelegate set_unreachable(url, unreachable_since \\ nil), to: @adapter
+
+  def reachability_time_threshold,
+    do: NaiveDateTime.add(NaiveDateTime.utc_now(), -30 * 24 * 3600, :second)
+end

lib/pleroma/instances/instance.ex

@@ -0,0 +1,77 @@
+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)
+    field(:reachability_checked_at, :naive_datetime)
+
+    timestamps()
+  end
+
+  def update_changeset(struct, params \\ %{}) do
+    struct
+    |> cast(params, [:host, :unreachable_since, :reachability_checked_at])
+    |> unique_constraint(:host)
+  end
+
+  def reachable?(url) do
+    !Repo.one(
+      from(i in Instance,
+        where:
+          i.host == ^host(url) and i.unreachable_since <= ^Instances.reachability_time_threshold(),
+        select: true
+      )
+    )
+  end
+
+  def set_reachable(url) do
+    Repo.update_all(
+      from(i in Instance, where: i.host == ^host(url)),
+      set: [
+        unreachable_since: nil,
+        reachability_checked_at: DateTime.utc_now()
+      ]
+    )
+  end
+
+  def set_unreachable(url, unreachable_since \\ nil) do
+    unreachable_since = unreachable_since || DateTime.utc_now()
+    host = host(url)
+    existing_record = Repo.get_by(Instance, %{host: host})
+
+    changes = %{
+      unreachable_since: unreachable_since,
+      reachability_checked_at: NaiveDateTime.utc_now()
+    }
+
+    if existing_record do
+      update_changes =
+        if existing_record.unreachable_since &&
+             NaiveDateTime.compare(existing_record.unreachable_since, unreachable_since) != :gt,
+           do: Map.delete(changes, :unreachable_since),
+           else: changes
+
+      {:ok, _instance} = Repo.update(update_changeset(existing_record, update_changes))
+    else
+      {:ok, _instance} = Repo.insert(update_changeset(%Instance{}, Map.put(changes, :host, host)))
+    end
+  end
+
+  defp host(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

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
@@ -721,7 +721,15 @@ def publish(actor, activity) do
     end)
   end
 
-  def publish_one(%{inbox: inbox, json: json, actor: actor, id: id}) do
+  def publish_one(%{inbox: inbox} = activity) do
+    if Instances.reachable?(inbox) do
+      do_publish_one(activity)
+    else
+      {:error, :noop}
+    end
+  end
+
+  defp do_publish_one(%{inbox: inbox, json: json, actor: actor, id: id}) do
     Logger.info("Federating #{id} to #{inbox}")
     host = URI.parse(inbox).host
 
@@ -734,6 +742,8 @@ def publish_one(%{inbox: inbox, json: json, actor: actor, id: id}) do
         digest: digest
       })
 
+    with {:ok, _} <-
+           result =
              @httpoison.post(
                inbox,
                json,
@@ -742,7 +752,14 @@ def publish_one(%{inbox: inbox, json: json, actor: actor, id: id}) do
                  {"signature", signature},
                  {"digest", digest}
                ]
-    )
+             ) do
+      Instances.set_reachable(inbox)
+      result
+    else
+      e ->
+        Instances.set_unreachable(inbox)
+        e
+    end
   end
 
   # TODO:

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
@@ -167,15 +168,23 @@ defp 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}} <-
+    with {:reachable, true} <- {:reachable, Instances.reachable?(url)},
+         {:ok, %{status: code}} <-
            poster.(
              url,
              feed,
              [{"Content-Type", "application/magic-envelope+xml"}]
            ) do
+      Instances.set_reachable(url)
       Logger.debug(fn -> "Pushed to #{url}, code #{code}" end)
     else
-      e -> Logger.debug(fn -> "Pushing Salmon to #{url} failed, #{inspect(e)}" end)
+      {:reachable, false} ->
+        Logger.debug(fn -> "Pushing Salmon to #{url} skipped as marked unreachable)" end)
+        :noop
+
+      e ->
+        Instances.set_unreachable(url)
+        Logger.debug(fn -> "Pushing Salmon to #{url} failed, #{inspect(e)}" end)
     end
   end
 

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}
@@ -267,7 +268,8 @@ def publish_one(%{xml: xml, topic: topic, callback: callback, secret: secret}) d
     signature = sign(secret || "", xml)
     Logger.info(fn -> "Pushing #{topic} to #{callback}" end)
 
-    with {:ok, %{status: code}} <-
+    with {:reachable, true} <- {:reachable, Instances.reachable?(callback)},
+         {:ok, %{status: code}} <-
            @httpoison.post(
              callback,
              xml,
@@ -276,10 +278,16 @@ def publish_one(%{xml: xml, topic: topic, callback: callback, secret: secret}) d
                {"X-Hub-Signature", "sha1=#{signature}"}
              ]
            ) do
+      Instances.set_reachable(callback)
       Logger.info(fn -> "Pushed to #{callback}, code #{code}" end)
       {:ok, code}
     else
+      {:reachable, false} ->
+        Logger.debug(fn -> "Pushing to #{callback} skipped as marked unreachable)" end)
+        {:error, :noop}
+
       e ->
+        Instances.set_unreachable(callback)
         Logger.debug(fn -> "Couldn't push to #{callback}, #{inspect(e)}" end)
         {:error, e}
     end

priv/repo/migrations/20190123125546_create_instances.exs

@@ -0,0 +1,16 @@
+defmodule Pleroma.Repo.Migrations.CreateInstances do
+  use Ecto.Migration
+
+  def change do
+    create table(:instances) do
+      add :host, :string
+      add :unreachable_since, :naive_datetime
+      add :reachability_checked_at, :naive_datetime
+
+      timestamps()
+    end
+
+    create unique_index(:instances, [:host])
+    create index(:instances, [:unreachable_since])
+  end
+end