Add function to provide IP as grouping key

Author: brian-brazil

README.md

@@ -262,6 +262,17 @@ push_to_gateway('localhost:9091', job='batchA', registry=registry)
 A separate registry is used, as the default registry may contain other metrics
 such as those from the Process Collector.
 
+Pushgateway functions take a grouping key. `push_to_gateway` replaces metrics
+with the same grouping key, `pushadd_to_gateway` only replaces metrics with the
+same name and grouping key and `delete_from_gateway` deletes metrics with the
+given job and grouping key. See the
+[Pushgateway documentation](https://github.com/prometheus/pushgateway/blob/master/README.md)
+for more information.
+
+`instance_ip_grouping_key` returns a grouping key with the instance label set
+to the host's IP address.
+
+
 ## Bridges
 
 It is also possible to expose metrics to systems other than Prometheus.

prometheus_client/__init__.py

@@ -24,6 +24,7 @@
 push_to_gateway = exposition.push_to_gateway
 pushadd_to_gateway = exposition.pushadd_to_gateway
 delete_from_gateway = exposition.delete_from_gateway
+instance_ip_grouping_key = exposition.instance_ip_grouping_key
 
 ProcessCollector = process_collector.ProcessCollector
 PROCESS_COLLECTOR = process_collector.PROCESS_COLLECTOR

prometheus_client/exposition.py

@@ -3,6 +3,7 @@
 from __future__ import unicode_literals
 
 import os
+import socket
 import time
 import threading
 
@@ -121,3 +122,9 @@ def _use_gateway(method, gateway, job, registry, grouping_key, timeout):
     if resp.code >= 400:
         raise IOError("error talking to pushgateway: {0} {1}".format(
             resp.code, resp.msg))
+
+def instance_ip_grouping_key():
+    '''Grouping key with instance set to the IP Address of this host.'''
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.connect(('', 0))
+    return {'instance': s.getsockname()[0]}

tests/test_client.py

@@ -7,7 +7,7 @@
 from prometheus_client import Gauge, Counter, Summary, Histogram, Metric
 from prometheus_client import CollectorRegistry, generate_latest, ProcessCollector
 from prometheus_client import push_to_gateway, pushadd_to_gateway, delete_from_gateway
-from prometheus_client import CONTENT_TYPE_LATEST
+from prometheus_client import CONTENT_TYPE_LATEST, instance_ip_grouping_key
 
 try:
     from BaseHTTPServer import BaseHTTPRequestHandler
@@ -456,6 +456,9 @@ def test_pushadd_with_groupingkey(self):
         self.assertEqual(self.requests[0][0].headers.get('content-type'), CONTENT_TYPE_LATEST)
         self.assertEqual(self.requests[0][1], b'')
 
+    def test_instance_ip_grouping_key(self):
+        self.assertTrue('' != instance_ip_grouping_key()['instance'])
+
 
 if __name__ == '__main__':
     unittest.main()