Add plugin Calico Felix

Change-Id: I5eb98f7edb38283e58b9706f899e2e641f407381
diff --git a/collectd/files/plugin/collectd_calico_felix.py b/collectd/files/plugin/collectd_calico_felix.py
new file mode 100644
index 0000000..f571796
--- /dev/null
+++ b/collectd/files/plugin/collectd_calico_felix.py
@@ -0,0 +1,157 @@
+#!/usr/bin/python
+#
+# Copyright 2017 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.
+#
+
+if __name__ == '__main__':
+    import collectd_fake as collectd
+else:
+    import collectd
+import re
+import requests
+
+import collectd_base as base
+
+
+NAME = 'calico_felix'
+# Default sampling interval
+INTERVAL = 60
+
+
+class CalicoFelixPlugin(base.Base):
+
+    def __init__(self, *args, **kwargs):
+        super(CalicoFelixPlugin, self).__init__(*args, **kwargs)
+        self.plugin = NAME
+        self.session = requests.Session()
+        self.session.mount(
+            'http://',
+            requests.adapters.HTTPAdapter(max_retries=self.max_retries)
+        )
+        self.session.mount(
+            'https://',
+            requests.adapters.HTTPAdapter(max_retries=self.max_retries)
+        )
+        self.url = None
+
+    def config_callback(self, config):
+        super(CalicoFelixPlugin, self).config_callback(config)
+        for node in config.children:
+            self.logger.debug("Got config request for '{}': {}".format(
+                node.key.lower(), node.values[0])
+            )
+            if node.key.lower() == "url":
+                self.url = node.values[0]
+
+    def itermetrics(self):
+        if self.url:
+            self.logger.debug("Requesting URL {}".format(
+                self.url)
+            )
+            try:
+                r = self.session.get(self.url, timeout=self.timeout)
+            except Exception as e:
+                msg = "Got exception for '{}': {}".format(self.url, e)
+                raise base.CheckException(msg)
+
+            if r.status_code != 200:
+                self.logger.error(
+                    ("{} responded with code {} "
+                     "").format(self.url,
+                                r.status_code))
+                raise base.CheckException(
+                    "Failed to gather Calico Felix metrics ({})".format(
+                        r.status_code
+                    )
+                )
+            self.logger.debug(
+                "Got response from {}: '{}'"
+                "".format(self.url, r.text))
+            # Example payload:
+            # # HELP felix_active_local_endpoints Number
+            # # of active endpoints on this host.
+            # # TYPE felix_active_local_endpoints gauge
+            # felix_active_local_endpoints 1
+            # # HELP felix_iptables_chains Number of active iptables chains.
+            # # TYPE felix_iptables_chains gauge
+            # felix_iptables_chains{ip_version="4",table="filter"} 14
+            # felix_iptables_chains{ip_version="4",table="nat"} 6
+            # felix_iptables_chains{ip_version="4",table="raw"} 6
+            # felix_iptables_chains{ip_version="6",table="filter"} 14
+            # felix_iptables_chains{ip_version="6",table="nat"} 6
+            # felix_iptables_chains{ip_version="6",table="raw"} 6
+            # # HELP go_goroutines Number of goroutines that currently exist.
+            # # TYPE go_goroutineqs gauge
+            # go_goroutines 39
+            for l in r.text.split('\n'):
+                # Line is empty or is a comment
+                if not l or l.startswith('#'):
+                    continue
+
+                (name, rval) = l.split()
+                self.logger.debug(
+                    "Got val for {}: '{}'".format(name, rval))
+                # For some metrics, remove the existing felix prefix
+                # to ensure homogeneity
+                if name.startswith('felix_'):
+                    name = name.replace('felix_', '', 1)
+                # Initialization of returned metric
+                ret_metric = {
+                    'values': rval
+                }
+                # Metric can have implicit dimensions. For example:
+                # felix_iptables_rules{ip_version="4",table="filter"}
+                m = re.search(
+                    '^(?P<name>[^{]+)(?:{(?P<dimensions>.[^}]+)})?$',
+                    name)
+                if not m:
+                    self.logger.error(
+                        "Error parsing metric name {}".format(
+                            name))
+                    continue
+
+                if m.group('dimensions'):
+                    name = m.group('name')
+                    meta = {}
+                    for d in m.group('dimensions').split(','):
+                        (k, v) = d.split('=')
+                        meta[k] = v.strip('"')
+                    if len(meta) > 0:
+                        ret_metric['meta'] = meta
+                ret_metric['type_instance'] = m.group('name')
+                yield ret_metric
+
+
+plugin = CalicoFelixPlugin(collectd)
+
+
+def config_callback(conf):
+    plugin.config_callback(conf)
+
+
+def notification_callback(notification):
+    plugin.notification_callback(notification)
+
+
+def read_callback():
+    plugin.conditional_read_callback()
+
+if __name__ == '__main__':
+    collectd.load_configuration(plugin)
+    plugin.read_callback()
+else:
+    collectd.register_config(config_callback)
+    collectd.register_notification(notification_callback)
+    collectd.register_read(read_callback, INTERVAL)