Elixir 1.19: Replace ugly old logger config checks with config merging

Side note: Going up in log levels doesn't work properly.
 - debug->info works
 - info->debug does not work

lib/pleroma/application.ex

@@ -132,6 +132,9 @@ defmodule Pleroma.Application do
       {:ok, _} ->
         Logger.debug("Successfully added logger backend: #{inspect(backend)}")
 
+      {:error, :already_present} ->
+        :ok
+
       {:error, reason} ->
         Logger.error("Failed to add logger backend #{inspect(backend)}: #{inspect(reason)}")
     end

lib/pleroma/config/deprecation_warnings.ex

@@ -20,6 +20,9 @@ defmodule Pleroma.Config.DeprecationWarnings do
      "\n* `config :pleroma, :instance, mrf_transparency_exclusions` is now `config :pleroma, :mrf, transparency_exclusions`"}
   ]
 
+  @logger_config_knobs [:level, :translator_inspect_opts]
+  @logger_formatter_config_knows [:colors, :format, :metadata, :truncate, :utc_log]
+
   def check_exiftool_filter do
     filters = Config.get([Pleroma.Upload]) |> Keyword.get(:filters, [])
 
@@ -417,54 +420,33 @@ defmodule Pleroma.Config.DeprecationWarnings do
     end
   end
 
+  defp merge_deprecated_logger_config(config) do
+    handler_config = Enum.filter(config, fn {k, _} -> k in @logger_config_knobs end)
+    formatter_config = Enum.filter(config, fn {k, _} -> k in @logger_formatter_config_knows end)
+    formatter = Logger.default_formatter(formatter_config)
+
+    Logger.debug("""
+    Reconfiguring console Logger with deprecated configuration syntax.
+      Handler configuration:
+        #{inspect(handler_config)}
+
+      Formatter:
+        #{inspect(formatter)}
+    """)
+
+    Logger.configure(handler_config)
+    :logger.update_handler_config(:default, :formatter, formatter)
+  end
+
   @spec check_deprecated_logger_config() :: :ok | :error
   def check_deprecated_logger_config do
-    mix_env = Pleroma.Config.get(:env)
-    config_file_name = "config/#{mix_env}.secret.exs"
-    config_file = File.read(config_file_name)
-
-    config_file =
-      case config_file do
-        {:ok, contents} ->
-          String.split(contents, "\n", trim: true)
-          |> Enum.reject(fn string -> String.starts_with?(string, "#") end)
-          |> Enum.join("\n")
-
-        _ ->
-          false
-      end
-
-    declared_deprecated_backend =
-      if is_binary(config_file) do
-        String.contains?(config_file, "config :logger, backends") or
-          String.contains?(config_file, "config :logger,\n  backends")
-      else
-        nil
-      end
-
-    declared_deprecated_console =
-      if is_binary(config_file) do
-        String.contains?(config_file, "config :logger, :console") or
-          String.contains?(config_file, "config :logger,\n  console")
-      else
-        nil
-      end
-
-    # We can't use Application.get_env/3, because by default default_formatter is populated
-    declared_new_console =
-      if is_binary(config_file) do
-        String.contains?(config_file, "config :logger, :default_handler") or
-          String.contains?(config_file, "config :logger,\n  :default_handler") or
-          String.contains?(config_file, "config :logger, :default_formatter") or
-          String.contains?(config_file, "config :logger,\n  :default_formatter")
-      else
-        nil
-      end
-
-    use_new_backend_config = Pleroma.Config.get([:logger, :backends])
+    backends_config = Application.get_env(:logger, :backends)
+    console_config = Application.get_env(:logger, :console)
 
+    # Note: No need to merge the old backends config since it still works.
+    # And new configuration will just add new Logger backends.
     backend =
-      if declared_deprecated_backend do
+      if backends_config do
         Logger.warning("""
         !!!DEPRECATION WARNING!!!
         Your configuration is using deprecated syntax for configuring backends of Elixir's logger.
@@ -483,7 +465,7 @@ defmodule Pleroma.Config.DeprecationWarnings do
       end
 
     console =
-      if declared_deprecated_console do
+      if console_config do
         Logger.warning("""
         !!!DEPRECATION WARNING!!!
         Your configuration is using deprecated syntax for configuring logging to console.
@@ -496,25 +478,13 @@ defmodule Pleroma.Config.DeprecationWarnings do
         `:default_formatter`. For more info visit: https://hexdocs.pm/logger/Logger.html#module-backends-and-backwards-compatibility
         """)
 
-        true
-      else
-        false
-      end
-
-    conflict =
-      if (!is_nil(use_new_backend_config) and declared_deprecated_backend) or
-           (declared_new_console and declared_deprecated_console) do
-        Logger.warning("""
-        !!!CONFIGURATION CONFLICT!!!
-        Pleroma has detected that both the deprecated way of configuring Logger and the new way are defined in your configuration.
-        Delete the deprecated configuration syntax.
-        """)
+        merge_deprecated_logger_config(console_config)
 
         true
       else
         false
       end
 
-    if backend or console or conflict, do: :error, else: :ok
+    if backend or console, do: :error, else: :ok
   end
 end

test/pleroma/config/deprecation_warnings_test.exs

@@ -392,11 +392,12 @@ defmodule Pleroma.Config.DeprecationWarningsTest do
   describe "check_deprecated_logger_config" do
     setup do
       Application.put_env(:logger, :backends, [:console, {ExSyslogger, :ex_syslogger}])
-      Application.put_env(:logger, :console, level: :warning)
+      Application.put_env(:logger, :console, level: :debug)
 
       on_exit(fn ->
         Application.delete_env(:logger, :backends)
         Application.delete_env(:logger, :console)
+        :logger.update_handler_config(:default, :formatter, Logger.default_formatter())
       end)
     end
 
@@ -432,5 +433,22 @@ defmodule Pleroma.Config.DeprecationWarningsTest do
                `:default_formatter`. For more info visit: https://hexdocs.pm/logger/Logger.html#module-backends-and-backwards-compatibility
                """
     end
+
+    test "reconfigures logger" do
+      log =
+        capture_log(fn ->
+          Pleroma.Config.DeprecationWarnings.check_deprecated_logger_config()
+        end)
+
+      # Formatter has inconsitent color formatting order
+      assert log =~
+               """
+               Reconfiguring console Logger with deprecated configuration syntax.
+                 Handler configuration:
+                   [level: :debug]
+
+                 Formatter:
+               """
+    end
   end
 end