chore: add logs message on deprecated routes (#1696)

lib/ae_mdw_web/plugs/deprecation_logger_plug.ex

@@ -0,0 +1,32 @@
+defmodule AeMdwWeb.Plugs.DeprecationLoggerPlug do
+  @moduledoc """
+  Logs useful information to detect deprecated endpoint clients.
+  """
+
+  alias Plug.Conn
+  alias AeMdw.Log
+
+  require Logger
+
+  @updated_prefixes ~w(status v2 v3)
+
+  @spec init([]) :: []
+  def init(opts), do: opts
+
+  @spec call(Conn.t(), []) :: Conn.t()
+  def call(%Conn{path_info: [path_prefix | _rest]} = conn, _opts)
+      when path_prefix in @updated_prefixes,
+      do: conn
+
+  def call(%Conn{request_path: request_path, remote_ip: remote_ip} = conn, _opts) do
+    referer =
+      case Conn.get_req_header(conn, "referer") do
+        [referer] -> referer
+        _no_match -> :inet.ntoa(remote_ip)
+      end
+
+    Log.info("[DEPRECATED] request: `#{request_path}`. referer: #{referer}")
+
+    conn
+  end
+end

lib/ae_mdw_web/router.ex

@@ -3,7 +3,7 @@ defmodule AeMdwWeb.Router do
   use Plug.ErrorHandler
 
   alias AeMdwWeb.Plugs.StatePlug
-  alias AeMdwWeb.Plugs.VersioningPlug
+  alias AeMdwWeb.Plugs.DeprecationLoggerPlug
   alias AeMdwWeb.Plugs.JSONFormatterPlug
   alias AeMdwWeb.Plugs.RequestSpan
   alias AeMdwWeb.Util
@@ -35,7 +35,7 @@ defmodule AeMdwWeb.Router do
     plug JSONFormatterPlug
     plug Plug.RequestId
     plug RequestSpan
-    plug VersioningPlug
+    plug DeprecationLoggerPlug
   end
 
   pipeline :browser do