[Config] handle .yaml.default files

review fix from #2273

config.py

@@ -771,10 +771,17 @@ def _all_configs_paths(osname, agentConfig):
     try:
         confd_path = get_confd_path(osname)
         all_configs = glob.glob(os.path.join(confd_path, '*.yaml'))
+        all_default_configs = glob.glob(os.path.join(confd_path, '*.yaml.default'))
     except PathNotFound, e:
         log.error("No conf.d folder found at '%s' or in the directory where the Agent is currently deployed.\n" % e.args[0])
         sys.exit(3)
 
+    if all_default_configs:
+        current_configs = set([_conf_path_to_check_name(conf) for conf in all_configs])
+        for default_config in all_default_configs:
+            if not _conf_path_to_check_name(default_config) in current_configs:
+                all_configs.append(default_config)
+
     # Compatibility code for the Nagios checks if it's still configured
     # in datadog.conf
     # FIXME: 6.x, should be removed
@@ -783,9 +790,11 @@ def _all_configs_paths(osname, agentConfig):
         if any([nagios_key in agentConfig for nagios_key in NAGIOS_OLD_CONF_KEYS]):
             all_configs.append('deprecated/nagios')
 
-
     return all_configs
 
+def _conf_path_to_check_name(conf_path):
+    return conf_path.rsplit('/', 1)[-1].split('.yaml')[0]
+
 def _checks_places(agentConfig, osname):
     """ Return methods to generated paths to inspect for a check provided it's name
     """
@@ -900,7 +909,7 @@ def load_check_directory(agentConfig, hostname):
 
     for config_path in all_configs_paths:
         # '/etc/dd-agent/checks.d/my_check.py' -> 'my_check'
-        check_name = config_path.rsplit('.', 1)[0].rsplit('/', 1)[-1]
+        check_name = _conf_path_to_check_name(config_path)
 
         conf_is_valid, check_config, invalid_check = _validate_config(config_path, check_name, agentConfig)
         init_failed_checks.update(invalid_check)

tests/core/fixtures/checks/valid_conf_2.yaml

@@ -0,0 +1,5 @@
+init_config:
+
+instances:
+  - host: localhost
+  - host: localh0st

tests/core/test_config.py

@@ -235,6 +235,27 @@ def testConfigDeprecatedNagiosConfig(self, *args):
         self.assertEquals(1, len(checks['initialized_checks']))
         self.assertEquals('valid_check_1', checks['initialized_checks'][0].check(None))
 
+    def testConfigDefault(self, *args):
+        copyfile('%s/valid_conf.yaml' % FIXTURE_PATH,
+            '%s/test_check.yaml.default' % TEMP_ETC_CONF_DIR)
+        copyfile('%s/valid_check_1.py' % FIXTURE_PATH,
+            '%s/test_check.py' % TEMP_ETC_CHECKS_DIR)
+        checks = load_check_directory({"additional_checksd": TEMP_ETC_CHECKS_DIR}, "foo")
+        self.assertEquals(1, len(checks['initialized_checks']))
+
+    def testConfigCustomOverDefault(self, *args):
+        copyfile('%s/valid_conf.yaml' % FIXTURE_PATH,
+            '%s/test_check.yaml.default' % TEMP_ETC_CONF_DIR)
+        # a 2nd valid conf file, slightly different so that we can test which one has been picked up
+        # (with 2 instances for instance)
+        copyfile('%s/valid_conf_2.yaml' % FIXTURE_PATH,
+            '%s/test_check.yaml' % TEMP_ETC_CONF_DIR)
+        copyfile('%s/valid_check_1.py' % FIXTURE_PATH,
+            '%s/test_check.py' % TEMP_ETC_CHECKS_DIR)
+        checks = load_check_directory({"additional_checksd": TEMP_ETC_CHECKS_DIR}, "foo")
+        self.assertEquals(1, len(checks['initialized_checks']))
+        self.assertEquals(2, checks['initialized_checks'][0].instance_count())  # check that we picked the right conf
+
     def tearDown(self):
         for _dir in self.TEMP_DIRS:
             rmtree(_dir)