Support OpenSearch protocol

config/config.exs

@@ -151,6 +151,7 @@ config :logger, :ex_syslogger,
 config :mime, :types, %{
   "application/xml" => ["xml"],
   "application/xrd+xml" => ["xrd+xml"],
+  "application/opensearchdescription+xml" => ["xml"],
   "application/jrd+json" => ["jrd+json"],
   "application/activity+json" => ["activity+json"],
   "application/ld+json" => ["activity+json"]

lib/pleroma/web/opensearch_controller.ex

@@ -0,0 +1,16 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.OpenSearchController do
+  use Pleroma.Web, :controller
+
+  plug(:skip_auth when action == :show)
+
+  @doc "GET /opensearch.xml"
+  def show(conn, _params) do
+    conn
+    |> put_resp_content_type("application/opensearchdescription+xml")
+    |> render("opensearch.xml")
+  end
+end

lib/pleroma/web/router.ex

@@ -156,6 +156,10 @@ defmodule Pleroma.Web.Router do
     plug(Pleroma.Web.Plugs.StaticFEPlug)
   end
 
+  pipeline :accepts_opensearch do
+    plug(:accepts, ["xml"])
+  end
+
   scope "/api/v1/pleroma", Pleroma.Web.TwitterAPI do
     pipe_through(:pleroma_api)
 
@@ -865,6 +869,12 @@ defmodule Pleroma.Web.Router do
     get("/web/manifest.json", MastoFEController, :manifest)
   end
 
+  scope "/", Pleroma.Web do
+    pipe_through(:accepts_opensearch)
+
+    get("/opensearch.xml", OpenSearchController, :show)
+  end
+
   scope "/", Pleroma.Web do
     pipe_through(:mastodon_html)
 

lib/pleroma/web/templates/open_search/opensearch.xml.eex

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
+  <ShortName><%= Config.get([:instance, :name]) %></ShortName>
+  <Description>Search through <%= Config.get([:instance, :name]) %></Description>
+  <InputEncoding>UTF-8</InputEncoding>
+  <Image width="16" height="16" type="image/x-icon"><%= Endpoint.url() %>/favicon.ico</Image>
+  <Image type="image/png"><%= Endpoint.url() %>/favicon.png</Image>
+  <Url type="text/html" method="get" template="<%= Endpoint.url() %>/search?query={searchTerms}"/>
+</OpenSearchDescription>

lib/pleroma/web/views/opensearch_view.ex

@@ -0,0 +1,9 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.OpenSearchView do
+  use Pleroma.Web, :view
+  alias Pleroma.Config
+  alias Pleroma.Web.Endpoint
+end

test/pleroma/web/opensearch_controller_test.exs

@@ -0,0 +1,21 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.OpenSearchControllerTest do
+  use Pleroma.Web.ConnCase, async: false
+  alias Pleroma.Config
+  alias Pleroma.Web.Endpoint
+
+  test "opensearch.xml", %{conn: conn} do
+    resp =
+      conn
+      |> put_req_header("accept", "application/opensearchdescription+xml")
+      |> get("/opensearch.xml")
+      |> response(200)
+
+    assert resp =~ "<ShortName>#{Config.get([:instance, :name])}</ShortName>"
+    assert resp =~ "<Description>Search through #{Config.get([:instance, :name])}</Description>"
+    assert resp =~ "template=\"#{Endpoint.url()}/search?query={searchTerms}\""
+  end
+end