Unhardcode logger log level

This patch unhardcodes log level in loggig.conf template.

Change-Id: I971520c8c98f652af01ff88fbda62c02721f4ba5
Related-Prod: https://mirantis.jira.com/browse/PROD-19921
diff --git a/README.rst b/README.rst
index 2b6483c..a7bab40 100644
--- a/README.rst
+++ b/README.rst
@@ -250,6 +250,25 @@
           ossyslog:
             enabled: true
 
+The log level might be configured per logger by using the
+following pillar structure:
+
+.. code-block:: yaml
+
+  ceilometer:
+    server:
+      logging:
+        loggers:
+          <logger_name>:
+            level: WARNING
+
+  ceilometer:
+    agent:
+      logging:
+        loggers:
+          <logger_name>:
+            level: WARNING
+
 
 More Information
 ================
diff --git a/ceilometer/files/logging.conf b/ceilometer/files/logging.conf
index fedad29..f3fb121 100644
--- a/ceilometer/files/logging.conf
+++ b/ceilometer/files/logging.conf
@@ -14,11 +14,11 @@
 keys = context, default{% if values.logging.log_handlers.get('fluentd', {}).get('enabled', False) %}, fluentd{% endif %}
 
 [logger_root]
-level = WARNING
+level = {{ values.logging.get('loggers', {}).get('root', {}).get('level', 'WARNING') }}
 handlers = {{ log_handlers | join(", ") }}
 
 [logger_ceilometer]
-level = INFO
+level = {{ values.logging.get('loggers', {}).get('ceilometer', {}).get('level', 'INFO') }}
 handlers = {{ log_handlers | join(", ") }}
 qualname = ceilometer
 propagate = 0