Add kea collector

src/collectors/kea/kea.py

@@ -0,0 +1,84 @@
+# coding=utf-8
+
+"""
+Collect dhcp stats from kea
+```
+
+#### Dependencies
+
+    * Kea with control-socket enabled
+    * It currently supports kea ipv4
+
+Example config file kea.conf
+```
+enabled=True
+control_socket_v4=/var/run/kea/kea-dhcp4.socket
+```
+
+"""
+
+import json
+import socket
+import diamond.collector
+from diamond.collector import str_to_bool
+from diamond import convertor
+from string import Template
+
+class KeaCollector(diamond.collector.Collector):
+
+    __metrics__ = [
+        'pkt4-received', 'pkt4-discover-received', 'pkt4-offer-received',
+        'pkt4-request-received', 'pkt4-ack-received', 'pkt4-nak-received',
+        'pkt4-receive-drop', 'pkt4-release-received', 'pkt4-decline-received',
+        'pkt4-inform-received', 'pkt4-unknown-received', 'pkt4-sent',
+        'pkt4-offer-sent', 'pkt4-ack-sent', 'pkt4-nak-sent',
+        'pkt4-parse-failed', 'pkt4-receive-drop', 'reclaimed-leases',
+        'declined-addresses', 'reclaimed-declined-addresses'
+    ]
+
+    __query__ = Template('{ "command": "statistic-get", "arguments": {"name": "$name"} }')
+
+
+
+    def get_default_config_help(self):
+        config_help = super(KeaCollector, self).get_default_config_help()
+        config_help.update({
+            'control_socket': 'Path to kea control socket',
+        })
+        return config_help
+
+    def get_default_config(self):
+        """Return default config
+
+        :rtype: dict
+        """
+        config = super(KeaCollector, self).get_default_config()
+        config.update({
+            'control_socket': '/var/run/kea/kea-dhcp4.socket',
+        })
+        return config
+
+    def get_kea_stats(self):
+        """Yield data from kea after reading it from the control socket
+        """
+        for item in self.__metrics__:
+            try:
+                conn = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+                conn.connect(self.config['control_socket'])
+                conn.sendall(self.__query__.substitute(name=item))
+                ### At the moment the payload has a maximum size of 8192
+                #   so I am limiting it to this size
+                data = json.loads(conn.recv(8192))
+                if 'arguments' in data and item in data['arguments']:
+                    yield (item, data['arguments'][item][0][0])
+                else:
+                    yield (item, 0)
+            finally:
+                conn.close()
+
+    def collect(self):
+        """Collect metrics from kea running locally 
+        """
+        for name, value in self.get_kea_stats():
+            self.publish(name, value)
+