improvement: add flag for agentx debugging

agentx/network.py always turned on debugging. It can be useful to have
debugging logs of the main application without the agentx debug logs, as
they are quite noisy.

Now, ./vpp-snmp-agent.py -d will turn on application debugging but NOT
agentx debugging. ./vpp-snmp-agent.py -d -dd will turn on both.

NOTE: ./vpp-snmp-agent.py -dd will do nothing, because the '-d' flag
determines the global logging level.

agentx/agent.py

@@ -28,7 +28,11 @@ class Agent(object):
         self._lastupdate = 0
         self._update_period = period  # Seconds
 
-        self._net = Network(server_address=server_address)
+        try:
+            debug = args.debug_agent
+        except:
+            debug = False
+        self._net = Network(server_address=server_address, debug=debug)
 
         self._oid_list = []
         self._args = args

agentx/network.py

@@ -27,11 +27,11 @@ class NetworkError(Exception):
 
 
 class Network:
-    def __init__(self, server_address="/var/agentx/master"):
+    def __init__(self, server_address="/var/agentx/master", debug=False):
 
         self.session_id = 0
         self.transaction_id = 0
-        self.debug = 1
+        self.debug = debug
         # Data Related Variables
         self.data = {}
         self.data_idx = []

vpp-snmp-agent.py

@@ -388,10 +388,16 @@ def main():
     parser.add_argument(
         "-d", dest="debug", action="store_true", help="""Enable debug, default False"""
     )
+    parser.add_argument(
+        "-dd",
+        dest="debug_agent",
+        action="store_true",
+        help="""Enable agentx debug, default False""",
+    )
 
     args = parser.parse_args()
     if args.debug:
-        print("Arguments:", args)
+        print(f"Arguments: {args}")
 
     agentx.setup_logging(debug=args.debug)