Fix webfinger not following redirections by using a custom dedicated Tesla client

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/service/http/rich_media_preview_client.ex

@@ -1,7 +1,6 @@
 defmodule Mobilizon.Service.HTTP.RichMediaPreviewClient do
   @moduledoc """
-  Tesla HTTP Basic Client
-  with JSON middleware
+  Tesla HTTP Basic Client that fetches HTML to extract metadata preview
   """
 
   use Tesla

lib/service/http/webfinger_client.ex

@@ -0,0 +1,34 @@
+defmodule Mobilizon.Service.HTTP.WebfingerClient do
+  @moduledoc """
+  Tesla HTTP Basic Client
+  with JSON middleware
+  """
+
+  use Tesla
+  alias Mobilizon.Config
+
+  @default_opts [
+    recv_timeout: 20_000
+  ]
+
+  adapter(Tesla.Adapter.Hackney, @default_opts)
+
+  @user_agent Config.instance_user_agent()
+
+  plug(Tesla.Middleware.FollowRedirects)
+
+  plug(Tesla.Middleware.Timeout, timeout: 10_000)
+
+  plug(Tesla.Middleware.Headers, [
+    {"User-Agent", @user_agent},
+    {"Accept", "application/json, application/activity+json, application/jrd+json"}
+  ])
+
+  plug(Tesla.Middleware.JSON,
+    decode_content_types: [
+      "application/jrd+json",
+      "application/json",
+      "application/activity+json"
+    ]
+  )
+end