Use docker hostname instead of default route to query cadvisor & kube…

…let (#2609)

* Use docker hostname instead of default route to query cadvisor & kubelet
* remove is_dockerized condition from DockerUtil get_hostname

checks.d/kubernetes.py

@@ -46,6 +46,7 @@
     RATE: {True: HISTORATE, False: RATE}
 }
 
+
 class Kubernetes(AgentCheck):
     """ Collect metrics and events from kubelet """
 

tests/checks/mock/test_kubernetes.py

@@ -49,6 +49,7 @@ def test_fail_1_1(self):
         }
 
         with mock.patch('utils.kubeutil.KubeUtil.retrieve_pods_list', side_effect=lambda: json.loads(Fixtures.read_file("pods_list_1.1.json", string_escape=False))):
+            with mock.patch('utils.dockerutil.DockerUtil.get_hostname', side_effect=lambda: 'foo'):
                 # Can't use run_check_twice due to specific metrics
                 self.run_check(config, mocks=mocks, force_reload=True)
                 self.assertServiceCheck("kubernetes.kubelet.check", status=AgentCheck.CRITICAL, tags=None, count=1)
@@ -69,6 +70,7 @@ def test_metrics_1_1(self):
         }
         # parts of the json returned by the kubelet api is escaped, keep it untouched
         with mock.patch('utils.kubeutil.KubeUtil.retrieve_pods_list', side_effect=lambda: json.loads(Fixtures.read_file("pods_list_1.1.json", string_escape=False))):
+            with mock.patch('utils.dockerutil.DockerUtil.get_hostname', side_effect=lambda: 'foo'):
                 # Can't use run_check_twice due to specific metrics
                 self.run_check_twice(config, mocks=mocks, force_reload=True)
 
@@ -125,6 +127,7 @@ def test_historate_1_1(self):
 
         # parts of the json returned by the kubelet api is escaped, keep it untouched
         with mock.patch('utils.kubeutil.KubeUtil.retrieve_pods_list', side_effect=lambda: json.loads(Fixtures.read_file("pods_list_1.1.json", string_escape=False))):
+            with mock.patch('utils.dockerutil.DockerUtil.get_hostname', side_effect=lambda: 'foo'):
                 # Can't use run_check_twice due to specific metrics
                 self.run_check_twice(config, mocks=mocks, force_reload=True)
 
@@ -163,6 +166,7 @@ def test_fail_1_2(self):
         }
 
         with mock.patch('utils.kubeutil.KubeUtil.retrieve_pods_list', side_effect=lambda: json.loads(Fixtures.read_file("pods_list_1.2.json", string_escape=False))):
+            with mock.patch('utils.dockerutil.DockerUtil.get_hostname', side_effect=lambda: 'foo'):
                 # Can't use run_check_twice due to specific metrics
                 self.run_check(config, mocks=mocks, force_reload=True)
                 self.assertServiceCheck("kubernetes.kubelet.check", status=AgentCheck.CRITICAL)
@@ -183,6 +187,7 @@ def test_metrics_1_2(self):
         }
         # parts of the json returned by the kubelet api is escaped, keep it untouched
         with mock.patch('utils.kubeutil.KubeUtil.retrieve_pods_list', side_effect=lambda: json.loads(Fixtures.read_file("pods_list_1.2.json", string_escape=False))):
+            with mock.patch('utils.dockerutil.DockerUtil.get_hostname', side_effect=lambda: 'foo'):
                 # Can't use run_check_twice due to specific metrics
                 self.run_check_twice(config, mocks=mocks, force_reload=True)
 
@@ -235,6 +240,7 @@ def test_historate_1_2(self):
 
         # parts of the json returned by the kubelet api is escaped, keep it untouched
         with mock.patch('utils.kubeutil.KubeUtil.retrieve_pods_list', side_effect=lambda: json.loads(Fixtures.read_file("pods_list_1.2.json", string_escape=False))):
+            with mock.patch('utils.dockerutil.DockerUtil.get_hostname', side_effect=lambda: 'foo'):
                 # Can't use run_check_twice due to specific metrics
                 self.run_check_twice(config, mocks=mocks, force_reload=True)
 

utils/dockerutil.py

@@ -108,12 +108,10 @@ def get_events(self):
 
     def get_hostname(self):
         """Return the `Name` param from `docker info` to use as the hostname"""
-        if self.is_dockerized():
-            try:
-                return self.client.info().get("Name")
-            except Exception:
-                log.critical("Unable to find docker host hostname")
-
+        try:
+            return self.client.info().get("Name")
+        except Exception:
+            log.critical("Unable to find docker host hostname")
         return None
 
     @property

utils/kubeutil.py

@@ -6,15 +6,14 @@
 from collections import defaultdict
 import logging
 import os
-import socket
-import struct
 from urlparse import urljoin
 
 # project
 from util import check_yaml
 from utils.checkfiles import get_conf_path
 from utils.http import retrieve_json
 from utils.singleton import Singleton
+from utils.dockerutil import DockerUtil
 
 log = logging.getLogger('collector')
 
@@ -39,6 +38,7 @@ class KubeUtil():
     NAMESPACE_LABEL = "io.kubernetes.pod.namespace"
 
     def __init__(self):
+        self.docker_util = DockerUtil()
         try:
             config_file_path = get_conf_path(KUBERNETES_CHECK_NAME)
             check_config = check_yaml(config_file_path)
@@ -53,7 +53,7 @@ def __init__(self):
             instance = {}
 
         self.method = instance.get('method', KubeUtil.DEFAULT_METHOD)
-        self.host = instance.get("host") or self._get_default_router()
+        self.host = instance.get("host") or self.docker_util.get_hostname()
 
         self.cadvisor_port = instance.get('port', KubeUtil.DEFAULT_CADVISOR_PORT)
         self.kubelet_port = instance.get('kubelet_port', KubeUtil.DEFAULT_KUBELET_PORT)
@@ -85,7 +85,7 @@ def extract_kube_labels(self, pods_list, excluded_keys=None):
             if name and labels and namespace:
                 key = "%s/%s" % (namespace, name)
 
-                for k,v in labels.iteritems():
+                for k, v in labels.iteritems():
                     if k in excluded_keys:
                         continue
 
@@ -95,16 +95,3 @@ def extract_kube_labels(self, pods_list, excluded_keys=None):
 
     def retrieve_pods_list(self):
         return retrieve_json(self.pods_list_url)
-
-    @classmethod
-    def _get_default_router(cls):
-        try:
-            with open('/proc/net/route') as f:
-                for line in f.readlines():
-                    fields = line.strip().split()
-                    if fields[1] == '00000000':
-                        return socket.inet_ntoa(struct.pack('<L', int(fields[2], 16)))
-        except IOError, e:
-            log.error('Unable to open /proc/net/route: %s', e)
-
-        return None