logging: Add support for per logger colors (fixes: #808)

docs/changelog.rst

@@ -53,6 +53,8 @@ v0.20.0 (UNRELEASED)
 - Add custom log level ``TRACE`` (numerical level 5), which can be used by
   Mopidy and extensions to log at an even more detailed level than ``DEBUG``.
 
+- Add support for per logger color overrides. (Fixes: :issue:`808`)
+
 **Local backend**
 
 - Add cover URL to all scanned files with MusicBrainz album IDs. (Fixes:

docs/config.rst

@@ -128,6 +128,14 @@ Logging configuration
     The ``loglevels`` config section can be used to change the log level for
     specific parts of Mopidy during development or debugging. Each key in the
     config section should match the name of a logger. The value is the log
+    level to use for that logger, one of ``black``, ``red``, ``green``,
+    ``yellow``, ``blue``, ``magenta``, ``cyan`` or ``white``.
+
+.. confval:: logcolors/*
+
+    The ``logcolors`` config section can be used to change the log color for
+    specific parts of Mopidy during development or debugging. Each key in the
+    config section should match the name of a logger. The value is the log
     level to use for that logger, one of ``debug``, ``info``, ``warning``,
     ``error``, or ``critical``.
 

mopidy/config/__init__.py

@@ -23,6 +23,7 @@ _logging_schema['debug_file'] = Path()
 _logging_schema['config_file'] = Path(optional=True)
 
 _loglevels_schema = MapConfigSchema('loglevels', LogLevel())
+_logcolors_schema = MapConfigSchema('logcolors', LogColor())
 
 _audio_schema = ConfigSchema('audio')
 _audio_schema['mixer'] = String()
@@ -42,7 +43,8 @@ _proxy_schema['password'] = Secret(optional=True)
 # NOTE: if multiple outputs ever comes something like LogLevelConfigSchema
 # _outputs_schema = config.AudioOutputConfigSchema()
 
-_schemas = [_logging_schema, _loglevels_schema, _audio_schema, _proxy_schema]
+_schemas = [_logging_schema, _loglevels_schema, _logcolors_schema,
+            _audio_schema, _proxy_schema]
 
 _INITIAL_HELP = """
 # For further information about options in this file see:

mopidy/config/types.py

@@ -6,7 +6,7 @@ import socket
 
 from mopidy import compat
 from mopidy.config import validators
-from mopidy.utils import path
+from mopidy.utils import log, path
 
 
 def decode(value):
@@ -197,6 +197,17 @@ class List(ConfigValue):
         return b'\n  ' + b'\n  '.join(encode(v) for v in value if v)
 
 
+class LogColor(ConfigValue):
+    def deserialize(self, value):
+        validators.validate_choice(value.lower(), log.COLORS)
+        return value.lower()
+
+    def serialize(self, value, display=False):
+        if value.lower() in log.COLORS:
+            return value.lower()
+        return b''
+
+
 class LogLevel(ConfigValue):
     """Log level value.
 

mopidy/utils/log.py

@@ -82,7 +82,7 @@ def setup_console_logging(config, verbosity_level):
     formatter = logging.Formatter(log_format)
 
     if config['logging']['color']:
-        handler = ColorizingStreamHandler()
+        handler = ColorizingStreamHandler(config.get('logcolors', {}))
     else:
         handler = logging.StreamHandler()
     handler.addFilter(verbosity_filter)
@@ -117,6 +117,11 @@ class VerbosityFilter(logging.Filter):
         return record.levelno >= required_log_level
 
 
+#: Available log colors.
+COLORS = [b'black', b'red', b'green', b'yellow', b'blue', b'magenta', b'cyan',
+          b'white']
+
+
 class ColorizingStreamHandler(logging.StreamHandler):
     """
     Stream handler which colorizes the log using ANSI escape sequences.
@@ -130,17 +135,6 @@ class ColorizingStreamHandler(logging.StreamHandler):
         Licensed under the new BSD license.
     """
 
-    color_map = {
-        'black': 0,
-        'red': 1,
-        'green': 2,
-        'yellow': 3,
-        'blue': 4,
-        'magenta': 5,
-        'cyan': 6,
-        'white': 7,
-    }
-
     # Map logging levels to (background, foreground, bold/intense)
     level_map = {
         TRACE_LOG_LEVEL: (None, 'blue', False),
@@ -150,11 +144,18 @@ class ColorizingStreamHandler(logging.StreamHandler):
         logging.ERROR: (None, 'red', False),
         logging.CRITICAL: ('red', 'white', True),
     }
+    # Map logger name to foreground colors
+    logger_map = {}
+
     csi = '\x1b['
     reset = '\x1b[0m'
 
     is_windows = platform.system() == 'Windows'
 
+    def __init__(self, logger_colors):
+        super(ColorizingStreamHandler, self).__init__()
+        self.logger_map = logger_colors
+
     @property
     def is_tty(self):
         isatty = getattr(self.stream, 'isatty', None)
@@ -173,19 +174,23 @@ class ColorizingStreamHandler(logging.StreamHandler):
         message = logging.StreamHandler.format(self, record)
         if not self.is_tty or self.is_windows:
             return message
-        return self.colorize(message, record)
-
-    def colorize(self, message, record):
+        for name, color in self.logger_map.iteritems():
+            if record.name.startswith(name):
+                return self.colorize(message, fg=color)
         if record.levelno in self.level_map:
             bg, fg, bold = self.level_map[record.levelno]
-            params = []
-            if bg in self.color_map:
-                params.append(str(self.color_map[bg] + 40))
-            if fg in self.color_map:
-                params.append(str(self.color_map[fg] + 30))
-            if bold:
-                params.append('1')
-            if params:
-                message = ''.join((
-                    self.csi, ';'.join(params), 'm', message, self.reset))
+            return self.colorize(message, bg=bg, fg=fg, bold=bold)
+        return message
+
+    def colorize(self, message, bg=None, fg=None, bold=False):
+        params = []
+        if bg in COLORS:
+            params.append(str(COLORS.index(bg) + 40))
+        if fg in COLORS:
+            params.append(str(COLORS.index(fg) + 30))
+        if bold:
+            params.append('1')
+        if params:
+            message = ''.join((
+                self.csi, ';'.join(params), 'm', message, self.reset))
         return message