Merge "Add Python collectd plugin to check memcached availability"

deployment_scripts/puppet/modules/lma_collector/README.md

@@ -657,12 +657,15 @@ to get statistics from RabbitMQ.
 #### Class: `lma_collector::collectd::memcached`
 
 Declare this class to configure collectd to collect Memcached statistics.
-collectd's native `memcached` plugin is used.
+collectd's native `memcached` plugin is used to collect statistics and a
+custom Python plugin is used to check the availability of Memcached server.
 
 ##### Parameters
 
 * `host`: *Required*. The Memcached host. Valid options: a string. See
   https://github.com/voxpupuli/puppet-collectd#class-collectdpluginmemcached.
+* `Port`: *Optional. The Memcached port. Valid option: an integer.
+  Default: `11211`.
 
 #### Class: `lma_collector::collectd::openstack_checks`
 

deployment_scripts/puppet/modules/lma_collector/files/collectd/collectd_memcached_check.py

@@ -0,0 +1,76 @@
+#!/usr/bin/python
+# Copyright 2016 Mirantis, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import collectd
+
+import collectd_base as base
+
+from pymemcache.client import base as memcache
+
+NAME = 'memcached'
+
+
+class MemcachedCheckPlugin(base.Base):
+
+    def __init__(self, *args, **kwargs):
+        super(MemcachedCheckPlugin, self).__init__(*args, **kwargs)
+        self.plugin = NAME
+        self.host = None
+        self.port = 11211
+
+    def config_callback(self, conf):
+        super(MemcachedCheckPlugin, self).config_callback(conf)
+
+        for node in conf.children:
+            if node.key == 'Host':
+                self.host = node.values[0]
+            if node.key == 'Port':
+                # Must coerce to integer to avoid getting a float value.
+                self.port = int(node.values[0])
+
+        if self.host is None:
+            self.logger.error('Missing Host parameter')
+
+    def read_callback(self):
+        try:
+
+            mc = memcache.Client((self.host, self.port))
+            mc.get('__get_non_existent_key__')
+            self.dispatch_check_metric(self.OK)
+        except Exception as e:
+            msg = 'Fail to query memcached ({}:{}): {}'.format(self.host,
+                                                               self.port,
+                                                               e)
+            self.logger.error(msg)
+            self.dispatch_check_metric(self.FAIL, msg)
+
+
+plugin = MemcachedCheckPlugin(collectd)
+
+
+def init_callback():
+    plugin.restore_sigchld()
+
+
+def config_callback(conf):
+    plugin.config_callback(conf)
+
+
+def read_callback():
+    plugin.read_callback()
+
+collectd.register_init(init_callback)
+collectd.register_config(config_callback)
+collectd.register_read(read_callback)

deployment_scripts/puppet/modules/lma_collector/manifests/collectd/memcached.pp

@@ -15,10 +15,21 @@
 
 class lma_collector::collectd::memcached (
   $host,
+  $port = 11211,
 ) {
 
+  validate_integer($port)
+
   class { 'collectd::plugin::memcached':
     host => $host,
+    port => $port,
+  }
+
+  lma_collector::collectd::python { 'collectd_memcached_check':
+    config => {
+      'Host' => "\"${host}\"",
+      'Port' => "\"${port}\"",
+    },
   }
 
 }

deployment_scripts/puppet/modules/lma_collector/spec/classes/lma_collector_collectd_memcached_spec.rb

@@ -21,7 +21,14 @@ describe 'lma_collector::collectd::memcached' do
 
     describe 'with host param' do
         let(:params) {{:host => 'example.com' }}
-        it { is_expected.to contain_class('collectd::plugin::memcached') \
-             .with_host('example.com') }
+        it {
+            is_expected.to contain_class('collectd::plugin::memcached') \
+             .with_host('example.com')
+            is_expected.to contain_lma_collector__collectd__python('collectd_memcached_check') \
+             .with_config({
+                "Host" => '"example.com"',
+                "Port" => '"11211"',
+                })
+            }
     end
 end