Add support for DD_ENV, DD_SERVICE, and DD_VERSION environment variables

datadog/dogstatsd/base.py

@@ -32,6 +32,14 @@
 # Tag name of entity_id
 ENTITY_ID_TAG_NAME = "dd.internal.entity_id"
 
+# Mapping of each "DD_" prefixed environment variable to a specific tag name
+DD_ENV_TAGS_MAPPING = {
+    'DD_ENTITY_ID': ENTITY_ID_TAG_NAME,
+    'DD_ENV': 'env',
+    'DD_SERVICE': 'service',
+    'DD_VERSION': 'version',
+}
+
 # Telemetry minimum flush interval in seconds
 DEFAULT_TELEMETRY_MIN_FLUSH_INTERVAL = 10
 
@@ -56,6 +64,24 @@ def __init__(self, host=DEFAULT_HOST, port=DEFAULT_PORT, max_buffer_size=50, nam
         If set, it overrides default value.
         :type DD_DOGSTATSD_PORT: integer
 
+        :envvar DATADOG_TAGS: Tags to attach to every metric reported by dogstatsd client.
+        :type DATADOG_TAGS: comma-delimited string
+
+        :envvar DD_ENTITY_ID: Tag to identify the client entity.
+        :type DD_ENTITY_ID: string
+
+        :envvar DD_ENV: the env of the service running the dogstatsd client.
+        If set, it is appended to the constant (global) tags of the statsd client.
+        :type DD_ENV: string
+
+        :envvar DD_SERVICE: the name of the service running the dogstatsd client.
+        If set, it is appended to the constant (global) tags of the statsd client.
+        :type DD_SERVICE: string
+
+        :envvar DD_VERSION: the version of the service running the dogstatsd client.
+        If set, it is appended to the constant (global) tags of the statsd client.
+        :type DD_VERSION: string
+
         :param host: the host of the DogStatsd server.
         :type host: string
 
@@ -75,12 +101,6 @@ def __init__(self, host=DEFAULT_HOST, port=DEFAULT_PORT, max_buffer_size=50, nam
         :param use_ms: Report timed values in milliseconds instead of seconds (default False)
         :type use_ms: boolean
 
-        :envvar DATADOG_TAGS: Tags to attach to every metric reported by dogstatsd client
-        :type DATADOG_TAGS: list of strings
-
-        :envvar DD_ENTITY_ID: Tag to identify the client entity.
-        :type DD_ENTITY_ID: string
-
         :param use_default_route: Dynamically set the DogStatsd host to the default route
         (Useful when running the client in a container) (Linux only)
         :type use_default_route: boolean
@@ -128,13 +148,14 @@ def __init__(self, host=DEFAULT_HOST, port=DEFAULT_PORT, max_buffer_size=50, nam
 
         # Options
         env_tags = [tag for tag in os.environ.get('DATADOG_TAGS', '').split(',') if tag]
+        # Inject values of DD_* environment variables as global tags.
+        for var, tag_name in DD_ENV_TAGS_MAPPING.items():
+            value = os.environ.get(var, '')
+            if value:
+                env_tags.append('{name}:{value}'.format(name=tag_name, value=value))
         if constant_tags is None:
             constant_tags = []
         self.constant_tags = constant_tags + env_tags
-        entity_id = os.environ.get('DD_ENTITY_ID')
-        if entity_id:
-            entity_tag = '{name}:{value}'.format(name=ENTITY_ID_TAG_NAME, value=entity_id)
-            self.constant_tags.append(entity_tag)
         if namespace is not None:
             namespace = text(namespace)
         self.namespace = namespace

tests/unit/dogstatsd/test_statsd.py

@@ -29,7 +29,7 @@
 from datadog.dogstatsd.context import TimedContextManagerDecorator
 from datadog.util.compat import is_higher_py35, is_p3k
 from datadog.util.config import get_version
-from tests.util.contextmanagers import preserve_environment_variable
+from tests.util.contextmanagers import preserve_environment_variable, EnvVars
 from tests.unit.dogstatsd.fixtures import load_fixtures
 
 
@@ -775,6 +775,62 @@ def test_entity_tag_and_tags_from_environment_and_constant(self):
         tags = "country:canada,red,country:china,age:45,blue,dd.internal.entity_id:04652bb7-19b7-11e9-9cc6-42010a9c016d"
         assert_equal_telemetry('gt:123.4|g|#'+tags, statsd.socket.recv(), telemetry=telemetry_metrics(tags=tags))
 
+    def test_dogstatsd_initialization_with_dd_env_service_version(self):
+        """
+        Dogstatsd should automatically use DD_ENV, DD_SERVICE, and DD_VERSION (if present)
+        to set {env, service, version} as global tags for all metrics emitted.
+        """
+        cases = [
+            # Test various permutations of setting DD_* env vars, as well as other global tag configuration.
+            # An empty string signifies that the env var either isn't set or that it is explicitly set to empty string.
+            ('', '', '', '', [], []),
+            ('prod', '', '', '', [], ['env:prod']),
+            ('prod', 'dog', '', '', [], ['env:prod', 'service:dog']),
+            ('prod', 'dog', 'abc123', '', [], ['env:prod', 'service:dog', 'version:abc123']),
+            ('prod', 'dog', 'abc123', 'env:prod,type:app', [], ['env:prod', 'env:prod', 'service:dog', 'type:app', 'version:abc123']),
+            ('prod', 'dog', 'abc123', 'env:prod2,type:app', [], ['env:prod', 'env:prod2', 'service:dog', 'type:app', 'version:abc123']),
+            ('prod', 'dog', 'abc123', '', ['env:prod', 'type:app'], ['env:prod', 'env:prod', 'service:dog', 'type:app', 'version:abc123']),
+            ('prod', 'dog', 'abc123', '', ['env:prod2', 'type:app'], ['env:prod', 'env:prod2', 'service:dog', 'type:app', 'version:abc123']),
+            ('prod', 'dog', 'abc123', 'env:prod3,custom_tag:cat', ['env:prod2', 'type:app'], ['custom_tag:cat', 'env:prod', 'env:prod2', 'env:prod3', 'service:dog', 'type:app', 'version:abc123']),
+        ]
+        for c in cases:
+            dd_env, dd_service, dd_version, datadog_tags, constant_tags, global_tags = c
+            with EnvVars(
+                env_vars={
+                    'DATADOG_TAGS': datadog_tags,
+                    'DD_ENV': dd_env,
+                    'DD_SERVICE': dd_service,
+                    'DD_VERSION': dd_version,
+                }
+            ):
+                statsd = DogStatsd(constant_tags=constant_tags, telemetry_min_flush_interval=0)
+                statsd.socket = FakeSocket()
+
+            # Guarantee consistent ordering, regardless of insertion order.
+            statsd.constant_tags.sort()
+            assert global_tags == statsd.constant_tags
+
+            # Make call with no tags passed; only the globally configured tags will be used.
+            global_tags_str = ','.join([t for t in global_tags])
+            statsd.gauge('gt', 123.4)
+            assert_equal_telemetry(
+                # Protect against the no tags case.
+                'gt:123.4|g|#{}'.format(global_tags_str) if global_tags_str else 'gt:123.4|g',
+                statsd.socket.recv(),
+                telemetry=telemetry_metrics(tags=global_tags_str)
+            )
+            statsd._reset_telementry()
+
+            # Make another call with local tags passed.
+            passed_tags = ['env:prod', 'version:def456', 'custom_tag:toad']
+            all_tags_str = ','.join([t for t in passed_tags + global_tags])
+            statsd.gauge('gt', 123.4, tags=passed_tags)
+            assert_equal_telemetry(
+                'gt:123.4|g|#{}'.format(all_tags_str),
+                statsd.socket.recv(),
+                telemetry=telemetry_metrics(tags=global_tags_str)
+            )
+
     def test_gauge_doesnt_send_None(self):
         self.statsd.gauge('metric', None)
         assert self.recv() is None