restrict remote users from indexing

lib/pleroma/web/metadata/restrict_indexing.ex

@@ -0,0 +1,25 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.Metadata.Providers.RestrictIndexing do
+  @behaviour Pleroma.Web.Metadata.Providers.Provider
+
+  @moduledoc """
+  Restricts indexing of remote users.
+  """
+
+  @impl true
+  def build_tags(%{user: %{local: false}}) do
+    [
+      {:meta,
+       [
+         name: "robots",
+         content: "noindex, noarchive"
+       ], []}
+    ]
+  end
+
+  @impl true
+  def build_tags(%{user: %{local: true}}), do: []
+end