Add support for custom endpoints

Added new configuration properties:
* ec2_endpoint_url
* monitoring_endpoint_url
that allow to override URLs used for
communicating with AWS API.

README.md

@@ -22,6 +22,8 @@ The default location of the configuration file used by collectd-cloudwatch plugi
  * __credentials_path__ - Used to point to AWS account configuration file
  * __region__ - Manual override for [region](http://docs.aws.amazon.com/general/latest/gr/rande.html#cw_region)  used to publish metrics
  * __host__ - Manual override for EC2 Instance ID and Host information propagated by collectd
+ * __ec2_endpoint_url__ - Manual override for EC2 endpoint
+ * __monitoring_endpoint_url__ - Manual override for Monitoring endpoint
  * __proxy_server_name__ - Manual override for proxy server name, used by plugin to connect aws cloudwatch at *.amazonaws.com.
  * __proxy_server_port__ - Manual override for proxy server port, used by plugin to connect aws cloudwatch at *.amazonaws.com.
  * __enable_high_resolution_metrics__ - The storage resolution is for high resolution support

src/cloudwatch/modules/configuration/confighelper.py

@@ -139,7 +139,11 @@ def _load_hostname(self):
                     " Using host information provided by Collectd.")
 
     def _set_ec2_endpoint(self):
-        """ Creates endpoint from region information """
+        """ Creates endpoint from region information (if the endpoint not explicitly set via ec2_endpoint_url) """
+        if self.config_reader.ec2_endpoint_url:
+            self.ec2_endpoint = self.config_reader.ec2_endpoint_url
+            return
+
         if self.region is "localhost":
             self.ec2_endpoint = "http://" + self.region + "/"
         elif self.region.startswith("cn-"):
@@ -179,7 +183,11 @@ def _load_flush_interval_in_seconds(self):
             self._LOGGER.warning("flush_interval_in_seconds in configuration is invalid: " + str(self.config_reader.flush_interval_in_seconds) + " use the default value: " + self.flush_interval_in_seconds)
 
     def _set_endpoint(self):
-        """ Creates endpoint from region information """
+        """ Creates endpoint from region information (if the endpoint not explicitly set via monitoring_endpoint_url) """
+        if self.config_reader.monitoring_endpoint_url:
+            self.endpoint = self.config_reader.monitoring_endpoint_url
+            return
+
         if self.region is "localhost":
             self.endpoint = "http://" + self.region + "/"
         elif self.region.startswith("cn-"):

src/cloudwatch/modules/configuration/configreader.py

@@ -39,6 +39,8 @@ class ConfigReader(object):
     PROXY_SERVER_PORT_KEY = "proxy_server_port"
     ENABLE_HIGH_DEFINITION_METRICS = "enable_high_resolution_metrics"
     FLUSH_INTERVAL_IN_SECONDS = "flush_interval_in_seconds"
+    EC2_ENDPOINT_URL = "ec2_endpoint_url"
+    MONITORING_ENDPOINT_URL = "monitoring_endpoint_url"
 
     def __init__(self, config_path):
         self.config_path = config_path
@@ -78,3 +80,5 @@ def _parse_config_file(self):
         self.push_asg = self.reader_utils.try_get_boolean(self.PUSH_ASG_KEY, self._PUSH_ASG_DEFAULT_VALUE)
         self.push_constant = self.reader_utils.try_get_boolean(self.PUSH_CONSTANT_KEY, self._PUSH_CONSTANT_DEFAULT_VALUE)
         self.constant_dimension_value = self.reader_utils.get_string(self.CONSTANT_DIMENSION_KEY)
+        self.ec2_endpoint_url = self.reader_utils.get_string(self.EC2_ENDPOINT_URL)
+        self.monitoring_endpoint_url = self.reader_utils.get_string(self.MONITORING_ENDPOINT_URL)