Fix increasing of verbosity using loglevels config

docs/changelog.rst

@@ -8,6 +8,12 @@ This changelog is used to track all major changes to Mopidy.
 v0.19.0 (unreleased)
 ====================
 
+**Configuration**
+
+- Fix the log setup so that it is possible to increase the amount of logging
+  from a specific logger using the ``loglevels`` config section. (Fixes:
+  :issue:`684`)
+
 **Models**
 
 - The type of :attr:`mopidy.models.Playlist.last_modified` has been redefined

mopidy/utils/log.py

@@ -62,10 +62,15 @@ LOG_LEVELS = {
 
 
 class VerbosityFilter(logging.Filter):
-    def __init__(self, verbosity_level):
+    def __init__(self, verbosity_level, loglevels):
         self.verbosity_level = verbosity_level
+        self.loglevels = loglevels
 
     def filter(self, record):
+        for name, required_log_level in self.loglevels.items():
+            if record.name == name or record.name.startswith(name + '.'):
+                return record.levelno >= required_log_level
+
         if record.name.startswith('mopidy'):
             required_log_level = LOG_LEVELS[self.verbosity_level]['mopidy']
         else:
@@ -79,7 +84,7 @@ def setup_console_logging(config, verbosity_level):
     if verbosity_level > max(LOG_LEVELS.keys()):
         verbosity_level = max(LOG_LEVELS.keys())
 
-    verbosity_filter = VerbosityFilter(verbosity_level)
+    verbosity_filter = VerbosityFilter(verbosity_level, config['loglevels'])
 
     if verbosity_level < 1:
         log_format = config['logging']['console_format']