feat(expert): make log level for log files configurable

apps/engine/lib/engine/bootstrap.ex

@@ -16,7 +16,8 @@ defmodule Engine.Bootstrap do
         document_store_entropy,
         app_configs,
         manager_node,
-        logger_global_metadata
+        logger_global_metadata,
+        log_level \\ :debug
       ) do
     :logger.update_primary_config(%{metadata: logger_global_metadata})
 
@@ -40,7 +41,7 @@ defmodule Engine.Bootstrap do
         Mix.env(:test)
         set_mix_build_path(project)
         ExUnit.start()
-        start_logger(project)
+        start_logger(project, log_level)
         maybe_change_directory(project)
         :ok
       end
@@ -73,7 +74,7 @@ defmodule Engine.Bootstrap do
     end
   end
 
-  defp start_logger(%Project{} = project) do
+  defp start_logger(%Project{} = project, log_level) do
     log_file_name =
       project
       |> Project.workspace_path("project.log")
@@ -88,7 +89,7 @@ defmodule Engine.Bootstrap do
         max_no_files: 1
       },
       formatter: Logger.Formatter.new(metadata: [:instance_id]),
-      level: :info
+      level: log_level
     }
 
     :logger.add_handler(handler_name, :logger_std_h, config)

apps/expert/lib/expert/application.ex

@@ -45,7 +45,13 @@ defmodule Expert.Application do
 
     {opts, _argv, _invalid} =
       OptionParser.parse(argv,
-        strict: [version: :boolean, help: :boolean, stdio: :boolean, port: :integer]
+        strict: [
+          version: :boolean,
+          help: :boolean,
+          stdio: :boolean,
+          port: :integer,
+          log_level: :string
+        ]
       )
 
     help_text = """
@@ -63,6 +69,7 @@ defmodule Expert.Application do
 
       --stdio             Use stdio as the transport mechanism
       --port <port>       Use TCP as the transport mechanism, with the given port
+      --log-level <level> Set log level for log files (debug, info, warning, error). Default: debug
       --help              Show this help message
       --version           Show Expert version
 
@@ -85,19 +92,26 @@ defmodule Expert.Application do
         :noop
     end
 
+    log_level = parse_log_level(opts[:log_level])
+    Application.put_env(:expert, :log_level, log_level)
+
     buffer_opts =
       cond do
         opts[:stdio] ->
           :ok = Expert.Logging.ProjectLogFile.attach()
           :ok = mute_default_log_handler()
           Logger.info("Expert v#{Expert.vsn()} starting on stdio")
+          apply_log_level(log_level)
           []
 
         is_integer(opts[:port]) ->
           :ok = Expert.Logging.ProjectLogFile.attach()
           :ok = mute_default_log_handler()
           IO.puts("Starting on port #{opts[:port]}")
+
           Logger.info("Expert v#{Expert.vsn()} starting on port #{opts[:port]}")
+
+          apply_log_level(log_level)
           [communication: {GenLSP.Communication.TCP, [port: opts[:port]]}]
 
         true ->
@@ -152,6 +166,25 @@ defmodule Expert.Application do
     {Document.Store, derive: [analysis: &Forge.Ast.analyze/1]}
   end
 
+  defp apply_log_level(log_level) do
+    Logger.info("Log level set to #{log_level}")
+
+    handler_name = Expert.Logging.ProjectLogFile.handler_name()
+    :logger.update_handler_config(handler_name, :level, log_level)
+    :logger.set_primary_config(:level, log_level)
+  end
+
+  defp parse_log_level(nil), do: :debug
+  defp parse_log_level("debug"), do: :debug
+  defp parse_log_level("info"), do: :info
+  defp parse_log_level("warning"), do: :warning
+  defp parse_log_level("error"), do: :error
+
+  defp parse_log_level(other) do
+    Logger.error("Invalid log level '#{other}'. Must be one of: debug, info, warning, error")
+    System.halt(2)
+  end
+
   defp mute_default_log_handler do
     case :logger.update_handler_config(:default, :level, :none) do
       :ok -> :ok

apps/expert/lib/expert/engine_node.ex

@@ -218,7 +218,8 @@ defmodule Expert.EngineNode do
       Node.self(),
       # Copy logger global metadata to engine instances.
       # Everything spawned from single expert instance will use same `instance_id`
-      :logger.get_primary_config().metadata
+      :logger.get_primary_config().metadata,
+      Application.get_env(:expert, :log_level, :debug)
     ]
 
     with {:ok, node_pid} <- EngineSupervisor.start_project_node(project),

apps/expert/lib/expert/logging/project_log_file.ex

@@ -8,9 +8,12 @@ defmodule Expert.Logging.ProjectLogFile do
     :expert_project_log
   end
 
-  def attach(root_path \\ File.cwd!()) when is_binary(root_path) do
+  def attach(opts \\ []) do
+    root_path = Keyword.get(opts, :root_path, File.cwd!())
+    level = Keyword.get(opts, :level, :debug)
+
     with :ok <- ensure_workspace(root_path) do
-      add_handler(log_config(root_path))
+      add_handler(log_config(root_path, level))
     end
   end
 
@@ -36,7 +39,7 @@ defmodule Expert.Logging.ProjectLogFile do
     |> :logger.add_handler(:logger_std_h, config)
   end
 
-  defp log_config(root_path) do
+  defp log_config(root_path, level) do
     log_file_name =
       root_path
       |> Path.join(".expert")
@@ -50,7 +53,7 @@ defmodule Expert.Logging.ProjectLogFile do
         max_no_files: @max_no_files
       },
       formatter: Logger.Formatter.new(metadata: [:instance_id]),
-      level: :debug
+      level: level
     }
   end
 end

apps/expert/test/expert/logging/project_log_file_test.exs

@@ -17,7 +17,7 @@ defmodule Expert.Logging.ProjectLogFileTest do
     log_path = Path.join([tmp_dir, ".expert", "expert.log"])
     gitignore_path = Path.join([tmp_dir, ".expert", ".gitignore"])
 
-    assert :ok = ProjectLogFile.attach(tmp_dir)
+    assert :ok = ProjectLogFile.attach(root_path: tmp_dir)
 
     Logger.info("project log file test")
     Logger.flush()
@@ -26,4 +26,12 @@ defmodule Expert.Logging.ProjectLogFileTest do
     assert File.read!(gitignore_path) == "*\n"
     assert File.regular?(log_path)
   end
+
+  @tag :tmp_dir
+  test "attach/1 applies the given log level to the handler", %{tmp_dir: tmp_dir} do
+    assert :ok = ProjectLogFile.attach(root_path: tmp_dir, level: :warning)
+
+    {:ok, config} = :logger.get_handler_config(ProjectLogFile.handler_name())
+    assert config.level == :warning
+  end
 end