Add a logging level configuration option

This change adds a logging level configuration option for the
server, allowing the admin to control what server activity gets
collected for logging. Unit tests have been added and updated to
cover this new configuration setting.

kmip/services/server/server.py

@@ -52,7 +52,8 @@ class KmipServer(object):
             log_path='/var/log/pykmip/server.log',
             policy_path=None,
             enable_tls_client_auth=None,
-            tls_cipher_suites=None
+            tls_cipher_suites=None,
+            logging_level=None
     ):
         """
         Create a KmipServer.
@@ -107,6 +108,11 @@ class KmipServer(object):
                 be used by the server when establishing a TLS connection with
                 a client. Optional, defaults to None. If None, the default set
                 of TLS cipher suites will be used.
+            logging_level (string): A logging level enumeration defined by the
+                logging package (e.g., DEBUG, INFO). Sets the base logging
+                level for the server. All log messages logged at this level or
+                higher in criticality will be logged. All log messages lower
+                in criticality will not be logged. Optional, defaults to None.
         """
         self._logger = logging.getLogger('kmip.server')
         self._setup_logging(log_path)
@@ -122,9 +128,12 @@ class KmipServer(object):
             auth_suite,
             policy_path,
             enable_tls_client_auth,
-            tls_cipher_suites
+            tls_cipher_suites,
+            logging_level
         )
 
+        self._logger.setLevel(self.config.settings.get('logging_level'))
+
         cipher_suites = self.config.settings.get('tls_cipher_suites')
         if self.config.settings.get('auth_suite') == 'TLS1.2':
             self.auth_suite = auth.TLS12AuthenticationSuite(cipher_suites)
@@ -169,7 +178,8 @@ class KmipServer(object):
             auth_suite=None,
             policy_path=None,
             enable_tls_client_auth=None,
-            tls_cipher_suites=None
+            tls_cipher_suites=None,
+            logging_level=None
     ):
         if path:
             self.config.load_settings(path)
@@ -198,6 +208,8 @@ class KmipServer(object):
                 'tls_cipher_suites',
                 tls_cipher_suites.split(',')
             )
+        if logging_level:
+            self.config.set_setting('logging_level', logging_level)
 
     def start(self):
         """
@@ -536,6 +548,18 @@ def build_argument_parser():
             "Optional, defaults to None."
         )
     )
+    parser.add_option(
+        "-v",
+        "--logging_level",
+        action="store",
+        type="str",
+        default=None,
+        dest="logging_level",
+        help=(
+            "A string representing the logging level for the server (e.g., "
+            "DEBUG, INFO). Optional, defaults to None."
+        )
+    )
 
     return parser
 
@@ -566,6 +590,8 @@ def main(args=None):
         kwargs['policy_path'] = opts.policy_path
     if opts.ignore_tls_client_auth:
         kwargs['enable_tls_client_auth'] = False
+    if opts.logging_level:
+        kwargs['logging_level'] = opts.logging_level
 
     # Create and start the server.
     s = KmipServer(**kwargs)