Add environment variable to disable statsd metric collection (#589)

* Add variable to disable statsd

* Update docs

* Address review

* Fix style nit

Signed-off-by: Daniel González Lopes <danielgonzalezlopes@gmail.com>

Co-authored-by: Jiri Kuncar <jiri.kuncar@gmail.com>

README.md

@@ -69,6 +69,8 @@ tags = ['version:1', 'application:web']
 api.Event.create(title=title, text=text, tags=tags)
 ```
 
+In development, you can disable any `statsd` metric collection using `DD_DOGSTATSD_DISABLE=True` (or any not-empty value).
+
 ## DogStatsD
 
 In order to use DogStatsD metrics, the Agent must be [running and available](https://docs.datadoghq.com/developers/dogstatsd/?tab=python).

datadog/dogstatsd/base.py

@@ -103,6 +103,9 @@ def __init__(
         If set, it is appended to the constant (global) tags of the statsd client.
         :type DD_VERSION: string
 
+        :envvar DD_DOGSTATSD_DISABLE: Disable any statsd metric collection (default False)
+        :type DD_DOGSTATSD_DISABLE: boolean
+
         :param host: the host of the DogStatsd server.
         :type host: string
 
@@ -157,6 +160,12 @@ def __init__(
                 log.warning("Port number provided in DD_DOGSTATSD_PORT env var is not an integer: \
                 %s, using %s as port number", dogstatsd_port, port)
 
+        # Check enabled
+        if os.environ.get('DD_DOGSTATSD_DISABLE') not in {'True', 'true', 'yes', '1'}:
+            self._enabled = True
+        else:
+            self._enabled = False
+
         # Connection
         self._max_payload_size = max_buffer_len
         if socket_path is not None:
@@ -445,6 +454,9 @@ def _report(self, metric, metric_type, value, tags, sample_rate):
         if value is None:
             return
 
+        if self._enabled is not True:
+            return
+
         if self._telemetry:
             self.metrics_count += 1