[check_marathon] Add marathon disable_ssl_validation and group support (

#3140)

* Add marathon disable_ssl_validation and group support

* Fix marathon_test for #3140

* Fix indentation for #3140

checks.d/marathon.py

@@ -12,6 +12,7 @@
 
 # project
 from checks import AgentCheck
+from config import _is_affirmative
 
 
 class Marathon(AgentCheck):
@@ -43,13 +44,19 @@ def check(self, instance):
             auth = (user,password)
         else:
             auth = None
+        ssl_verify = not _is_affirmative(instance.get('disable_ssl_validation', False))
+        group = instance.get('group', None)
 
         instance_tags = instance.get('tags', [])
         default_timeout = self.init_config.get('default_timeout', self.DEFAULT_TIMEOUT)
         timeout = float(instance.get('timeout', default_timeout))
 
         # Marathon apps
-        response = self.get_json(urljoin(url, "v2/apps"), timeout, auth)
+        if group is None:
+            marathon_path = urljoin(url, "v2/apps")
+        else:
+            marathon_path = urljoin(url, "v2/groups/{}".format(group))
+        response = self.get_json(marathon_path, timeout, auth, ssl_verify)
         if response is not None:
             self.gauge('marathon.apps', len(response['apps']), tags=instance_tags)
             for app in response['apps']:
@@ -59,13 +66,13 @@ def check(self, instance):
                         self.gauge('marathon.' + attr, app[attr], tags=tags)
 
         # Number of running/pending deployments
-        response = self.get_json(urljoin(url, "v2/deployments"), timeout, auth)
+        response = self.get_json(urljoin(url, "v2/deployments"), timeout, auth, ssl_verify)
         if response is not None:
             self.gauge('marathon.deployments', len(response), tags=instance_tags)
 
-    def get_json(self, url, timeout, auth):
+    def get_json(self, url, timeout, auth, verify):
         try:
-            r = requests.get(url, timeout=timeout, auth=auth)
+            r = requests.get(url, timeout=timeout, auth=auth, verify=verify)
             r.raise_for_status()
         except requests.exceptions.Timeout:
             # If there's a timeout

conf.d/marathon.yaml.example

@@ -9,3 +9,9 @@ instances:
   #   if marathon is protected by basic auth
   #   user: "username"
   #   password: "password"
+  #
+  #   to disable ssl validation
+  #   disable_ssl_validation: true
+  #
+  #   to get metrics from just one application group:
+  #   group: product

tests/checks/mock/test_marathon.py

@@ -32,7 +32,7 @@ class MarathonCheckTest(AgentCheckTest):
     CHECK_NAME = 'marathon'
 
     def test_default_configuration(self):
-        def side_effect(url, timeout, auth):
+        def side_effect(url, timeout, auth, verify):
             if "v2/apps" in url:
                 return Fixtures.read_json_file("apps.json")
             elif "v2/deployments" in url:
@@ -46,7 +46,7 @@ def side_effect(url, timeout, auth):
 
 
     def test_empty_responses(self):
-        def side_effect(url, timeout, auth):
+        def side_effect(url, timeout, auth, verify):
             if "v2/apps" in url:
                 return {"apps": []}
             elif "v2/deployments" in url: