Make trace logging optional and allow selective enabling

Because coloredlogs' install changes the level of the root handler, the
setLevel call had to be moved to after the install.

3 files changed, 19 insertions, 9 deletions

diff --git a/bot/constants.py b/bot/constants.py
index 6d14bbb3a..14400700f 100644
--- a/bot/constants.py
+++ b/bot/constants.py
@@ -199,6 +199,7 @@ class Bot(metaclass=YAMLGetter):
     prefix: str
     sentry_dsn: Optional[str]
     token: str
+    trace_loggers: Optional[str]
 
 
 class Redis(metaclass=YAMLGetter):
diff --git a/bot/log.py b/bot/log.py
index e92233a33..339ed63a7 100644
--- a/bot/log.py
+++ b/bot/log.py
@@ -20,7 +20,6 @@ def setup() -> None:
     logging.addLevelName(TRACE_LEVEL, "TRACE")
     Logger.trace = _monkeypatch_trace
 
-    log_level = TRACE_LEVEL if constants.DEBUG_MODE else logging.INFO
     format_string = "%(asctime)s | %(name)s | %(levelname)s | %(message)s"
     log_format = logging.Formatter(format_string)
 
@@ -30,7 +29,6 @@ def setup() -> None:
     file_handler.setFormatter(log_format)
 
     root_log = logging.getLogger()
-    root_log.setLevel(log_level)
     root_log.addHandler(file_handler)
 
     if "COLOREDLOGS_LEVEL_STYLES" not in os.environ:
@@ -44,11 +42,9 @@ def setup() -> None:
     if "COLOREDLOGS_LOG_FORMAT" not in os.environ:
         coloredlogs.DEFAULT_LOG_FORMAT = format_string
 
-    if "COLOREDLOGS_LOG_LEVEL" not in os.environ:
-        coloredlogs.DEFAULT_LOG_LEVEL = log_level
-
-    coloredlogs.install(logger=root_log, stream=sys.stdout)
+    coloredlogs.install(level=logging.TRACE, logger=root_log, stream=sys.stdout)
 
+    root_log.setLevel(logging.DEBUG if constants.DEBUG_MODE else logging.INFO)
     logging.getLogger("discord").setLevel(logging.WARNING)
     logging.getLogger("websockets").setLevel(logging.WARNING)
     logging.getLogger("chardet").setLevel(logging.WARNING)
@@ -57,6 +53,8 @@ def setup() -> None:
     # Set back to the default of INFO even if asyncio's debug mode is enabled.
     logging.getLogger("asyncio").setLevel(logging.INFO)
 
+    _set_trace_loggers()
+
 
 def setup_sentry() -> None:
     """Set up the Sentry logging integrations."""
@@ -86,3 +84,13 @@ def _monkeypatch_trace(self: logging.Logger, msg: str, *args, **kwargs) -> None:
     """
     if self.isEnabledFor(TRACE_LEVEL):
         self._log(TRACE_LEVEL, msg, args, **kwargs)
+
+
+def _set_trace_loggers() -> None:
+    """Set loggers to the trace level according to the value from the BOT_TRACE_LOGGERS env var."""
+    if constants.Bot.trace_loggers:
+        if constants.Bot.trace_loggers in {"*", "ROOT"}:
+            logging.getLogger().setLevel(logging.TRACE)
+        else:
+            for logger_name in constants.Bot.trace_loggers.split(","):
+                logging.getLogger(logger_name).setLevel(logging.TRACE)
diff --git a/config-default.yml b/config-default.yml
index 8c6e18470..b9786925d 100644
--- a/config-default.yml
+++ b/config-default.yml
@@ -1,7 +1,8 @@
 bot:
-    prefix:      "!"
-    sentry_dsn:  !ENV "BOT_SENTRY_DSN"
-    token:       !ENV "BOT_TOKEN"
+    prefix:         "!"
+    sentry_dsn:     !ENV "BOT_SENTRY_DSN"
+    token:          !ENV "BOT_TOKEN"
+    trace_loggers:  !ENV "BOT_TRACE_LOGGERS"
 
     clean:
         # Maximum number of messages to traverse for clean commands