Let favicon be configurable

config/config.exs

@@ -190,6 +190,7 @@
   short_description: "",
   background_image: "/images/city.jpg",
   instance_thumbnail: "/instance/thumbnail.png",
+  favicon: "/favicon.png",
   limit: 5_000,
   description_limit: 5_000,
   remote_limit: 100_000,

config/description.exs

@@ -988,6 +988,12 @@
           "The instance thumbnail can be any image that represents your instance and is used by some apps or services when they display information about your instance.",
         suggestions: ["/instance/thumbnail.jpeg"]
       },
+      %{
+        key: :favicon,
+        type: {:string, :image},
+        description: "Shortcut icon displayed in the browser, and possibly displayed by other instances.",
+        suggestions: ["/favicon.png"]
+      },
       %{
         key: :show_reactions,
         type: :boolean,

lib/pleroma/web/fallback/redirect_controller.ex

@@ -33,19 +33,7 @@ def redirector_with_meta(conn, %{"maybe_nickname_or_id" => maybe_nickname_or_id}
   end
 
   def redirector_with_meta(conn, params) do
-    {:ok, index_content} = File.read(index_file_path())
-
-    tags = build_tags(conn, params)
-    preloads = preload_data(conn, params)
-    title = "<title>#{Pleroma.Config.get([:instance, :name])}</title>"
-
-    response =
-      index_content
-      |> String.replace("<!--server-generated-meta-->", tags <> preloads <> title)
-
-    conn
-    |> put_resp_content_type("text/html")
-    |> send_resp(200, response)
+    redirector_with_ssr(conn, params, [:tags, :preload, :title, :favicon])
   end
 
   def redirector_with_preload(conn, %{"path" => ["pleroma", "admin"]}) do
@@ -53,13 +41,17 @@ def redirector_with_preload(conn, %{"path" => ["pleroma", "admin"]}) do
   end
 
   def redirector_with_preload(conn, params) do
+    redirector_with_ssr(conn, params, [:preload, :title, :favicon])
+  end
+
+  defp redirector_with_ssr(conn, params, keys) do
     {:ok, index_content} = File.read(index_file_path())
-    preloads = preload_data(conn, params)
-    title = "<title>#{Pleroma.Config.get([:instance, :name])}</title>"
+
+    meta = compose_meta(conn, params, keys)
 
     response =
       index_content
-      |> String.replace("<!--server-generated-meta-->", preloads <> title)
+      |> String.replace("<!--server-generated-meta-->", Enum.join(meta))
 
     conn
     |> put_resp_content_type("text/html")
@@ -80,7 +72,13 @@ defp index_file_path do
     Pleroma.Web.Plugs.InstanceStatic.file_path("index.html")
   end
 
-  defp build_tags(conn, params) do
+  defp compose_meta(conn, params, attrs) when is_list(attrs) do
+    Enum.map(attrs, fn attr ->
+      build_meta(attr, {conn, params})
+    end)
+  end
+
+  defp build_meta(:tags, {conn, params}) do
     try do
       Metadata.build_tags(params)
     rescue
@@ -94,7 +92,7 @@ defp build_tags(conn, params) do
     end
   end
 
-  defp preload_data(conn, params) do
+  defp build_meta(:preload, {conn, params}) do
     try do
       Preload.build_tags(conn, params)
     rescue
@@ -107,4 +105,12 @@ defp preload_data(conn, params) do
         ""
     end
   end
+
+  defp build_meta(:title, _) do
+    "<title>#{Pleroma.Config.get([:instance, :name])}</title>"
+  end
+
+  defp build_meta(:favicon, _) do
+    "<link rel=\"icon\" href=\"#{Pleroma.Config.get([:instance, :favicon])}\">"
+  end
 end

priv/static/index.html

@@ -4,7 +4,6 @@
     <title>Welcome to Rebased</title>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width,initial-scale=1,viewport-fit=cover,user-scalable=no">
-    <link rel="icon" type="image/png" href="/favicon.png">
     <style type="text/css">
       :root {
         --brand-color: #0482d8;

test/pleroma/web/fallback_test.exs

@@ -31,6 +31,7 @@ test "GET /*path adds a title", %{conn: conn} do
   describe "preloaded data and metadata attached to" do
     test "GET /:maybe_nickname_or_id", %{conn: conn} do
       clear_config([:instance, :name], "a cool title")
+      clear_config([:instance, :favicon], "/favicon.svg")
 
       user = insert(:user)
       user_missing = get(conn, "/foo")
@@ -40,6 +41,7 @@ test "GET /:maybe_nickname_or_id", %{conn: conn} do
       refute html_response(user_present, 200) =~ "<!--server-generated-meta-->"
       assert html_response(user_present, 200) =~ "initial-results"
       assert html_response(user_present, 200) =~ "<title>a cool title</title>"
+      assert html_response(user_present, 200) =~ "<link rel=\"icon\" href=\"/favicon.svg\">"
     end
 
     test "GET /*path", %{conn: conn} do