Granular logging control

Following commits matches the logging behaviour
that can be found in monasca-log-api and will be available
in monasca-api.
With it, it is possible to granullary control severities
of different components of monasca-persister.
Provides logging to the console and file.
File logging has rotating capability enabled.

Change-Id: If16138b38a5a4344c18eefe159d80585a8c68819

etc/monasca/persister-logging.conf

@@ -0,0 +1,50 @@
+[loggers]
+keys = root, kafka, influxdb, cassandra
+
+[handlers]
+keys = console, file
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = DEBUG
+formatter = default
+handlers = console, file
+
+[logger_kafka]
+qualname = kafka
+level = DEBUG
+formatter = default
+handlers = console, file
+propagate = 0
+
+[logger_influxdb]
+qualname = influxdb
+level = DEBUG
+formatter = default
+handlers = console, file
+propagate = 0
+
+[logger_cassandra]
+qualname = cassandra
+level = DEBUG
+formatter = default
+handlers = console, file
+propagate = 0
+
+[handler_console]
+class = logging.StreamHandler
+args = (sys.stderr,)
+level = DEBUG
+formatter = generic
+
+[handler_file]
+class = logging.handlers.RotatingFileHandler
+level = DEBUG
+formatter = generic
+# store up to 5*100MB of logs
+args = ('/var/log/monasca/persister/persister.log', 'a', 104857600, 5)
+
+[formatter_generic]
+format = %(asctime)s %(levelname)s [%(name)s][%(threadName)s] %(message)s

etc/monasca/persister.conf

@@ -1,11 +1,5 @@
 [DEFAULT]
-log_file = persister.log
-log_dir = /var/log/monasca/persister
-# Default log level is WARNING
-# Show debugging output in logs (sets DEBUG log level output)
-debug = false
-# Show more verbose log output (sets INFO log level output) if debug is False
-verbose = true
+log_config_append=/etc/monasca/persister-logging.conf
 
 [repositories]
 # The driver to use for the metrics repository