Add Kubernetes configuration provider which writes config to a secret

Fixes #145

health/healthcheck.py

@@ -4,14 +4,15 @@ from health.services import check_all_services
 
 logger = logging.getLogger(__name__)
 
-def get_healthchecker(app):
+def get_healthchecker(app, config_provider):
   """ Returns a HealthCheck instance for the given app. """
-  return HealthCheck.get_checker(app)
+  return HealthCheck.get_checker(app, config_provider)
 
 
 class HealthCheck(object):
-  def __init__(self, app):
+  def __init__(self, app, config_provider):
     self.app = app
+    self.config_provider = config_provider
 
   def check_instance(self):
     """
@@ -52,20 +53,21 @@ class HealthCheck(object):
     data = {
       'services': service_statuses,
       'notes': notes,
-      'is_testing': self.app.config['TESTING']
+      'is_testing': self.app.config['TESTING'],
+      'config_provider': self.config_provider.provider_id
     }
 
     return (data, 200 if is_healthy else 503)
 
 
   @classmethod
-  def get_checker(cls, app):
+  def get_checker(cls, app, config_provider):
     name = app.config['HEALTH_CHECKER'][0]
     parameters = app.config['HEALTH_CHECKER'][1] or {}
 
     for subc in cls.__subclasses__():
       if subc.check_name() == name:
-        return subc(app, **parameters)
+        return subc(app, config_provider, **parameters)
 
     raise Exception('Unknown health check with name %s' % name)
 
@@ -77,8 +79,8 @@ class LocalHealthCheck(HealthCheck):
 
 
 class ProductionHealthCheck(HealthCheck):
-  def __init__(self, app, access_key, secret_key, db_instance='quay'):
-    super(ProductionHealthCheck, self).__init__(app)
+  def __init__(self, app, config_provider, access_key, secret_key, db_instance='quay'):
+    super(ProductionHealthCheck, self).__init__(app, config_provider)
     self.access_key = access_key
     self.secret_key = secret_key
     self.db_instance = db_instance