Changing approach to update component status, but still missing push metrics.

cachet_url_monitor/configuration.py

@@ -1,10 +1,15 @@
+#!/usr/bin/env python
 import abc
+import logging
 import requests
 import timeit
 from yaml import load
 
 
 class Configuration(object):
+    """Represents a configuration file, but it also includes the functionality
+    of assessing the API and pushing the results to cachet.
+    """
     def __init__(self, config_file):
         #TODO(mtakaki|2016-04-26): Needs validation if the config is correct.
         self.config_file = config_file
@@ -13,22 +18,50 @@ class Configuration(object):
                 in self.data['endpoint']['expectation']]
 
     def evaluate(self):
-        self.request = requests.request(self.data['endpoint']['method'],
-                self.data['endpoint']['url'])
-        self.status = True
+        #TODO(mtakaki|2016-04-27): Add support to configurable timeout.
+        try:
+            self.request = requests.request(self.data['endpoint']['method'],
+                    self.data['endpoint']['url'])
+        except requests.ConnectionError:
+            logging.warning('The URL is unreachable: %s %s' %
+                    (self.data['endpoint']['method'],
+                        self.data['endpoint']['url']))
+            self.status = 3
+            return
+        except requests.HTTPError:
+            logging.exception('Unexpected HTTP response')
+            self.status = 3
+            return
+        except requests.Timeout:
+            logging.warning('Request timed out')
+            self.status = 3
+            return
+
+        # We, by default, assume the API is healthy.
+        self.status = 1
         self.message = ''
         for expectation in self.expectations:
-            status = expectation.is_healthy(self.request)
-            self.status = self.status and status
+            status = expectation.get_status(self.request)
+
+            # The greater the status is, the worse the state of the API is.
+            if status > self.status:
+                self.status = status
 
     def push_status_and_metrics(self):
-        if not self.status:
-            params = {'id': self.data['cachet']['component_id'], 'status': 0}
-            headers = {'X-Cachet-Token': self.data['cachet']['token']}
-            incident_request = requests.post('%s/api/v1/components/%d' %
-                    (self.data['cachet']['api_url'],
-                    self.data['cachet']['component_id']),
-                    params=params, headers=headers)
+        params = {'id': self.data['cachet']['component_id'], 'status':
+                self.status}
+        headers = {'X-Cachet-Token': self.data['cachet']['token']}
+        component_request = requests.put('%s/components/%d' %
+                (self.data['cachet']['api_url'],
+                self.data['cachet']['component_id']),
+                params=params, headers=headers)
+        if component_request.status_code == 200:
+            # Successful update
+            logging.info('Component update: status [%d]' % (self.status,))
+        else:
+            # Failed to update the API status
+            logging.warning('Component update failed with status [%d]: API'
+                    ' status: [%d]' % (component_request.status_code, self.status))
 
 class Expectaction(object):
     @staticmethod
@@ -40,8 +73,10 @@ class Expectaction(object):
         return expectations.get(configuration['type'])(configuration)
 
     @abc.abstractmethod
-    def is_healthy(self, response):
-        """Returns true if the endpoint is healthy and false if otherwise."""
+    def get_status(self, response):
+        """Returns the status of the API, following cachet's component status
+        documentation: https://docs.cachethq.io/docs/component-statuses
+        """
 
     @abc.abstractmethod
     def get_message(self, response):
@@ -52,8 +87,11 @@ class HttpStatus(Expectaction):
     def __init__(self, configuration):
         self.status = configuration['status']
 
-    def is_healthy(self, response):
-        return response.status_code == self.status
+    def get_status(self, response):
+        if response.status_code == self.status:
+            return 1
+        else:
+            return 3
 
     def get_message(self, response):
         return 'Unexpected HTTP status (%s)' % (response.status_code,)
@@ -63,9 +101,11 @@ class Latency(Expectaction):
     def __init__(self, configuration):
         self.threshold = configuration['threshold']
 
-    def is_healthy(self, response):
-        return response.elapsed.total_seconds() <= self.threshold 
+    def get_status(self, response):
+        if response.elapsed.total_seconds() <= self.threshold:
+            return 1
+        else:
+            return 2
 
     def get_message(self, response):
-        return 'Latency above threshold: %d' %
-    (response.elapsed.total_seconds(),)
+        return 'Latency above threshold: %d' % (response.elapsed.total_seconds(),)

cachet_url_monitor/scheduler.py

@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+from threading import Timer
+import configuration
+
+
+class Agent(object):
+    def __init__(self, configuration):
+        self.configuration = configuration
+
+

config.yml

@@ -5,7 +5,7 @@ endpoint:
     - type: HTTP_STATUS
       status: 200
     - type: LATENCY
-      threshold: 80
+      threshold: 1
 cachet:
   api_url: http://status.cachethq.io/api/v1/
   token: my_token