feat(api): per-endpoint metric tags

This allows endpoints to add tags to the resulting `view.response`
metric that gets recorded in middleware.

The immediate use for this is to tag all Integration Platform endpoints
with a corresponding tag so that we can split them out downstream.

src/sentry/api/base.py

@@ -127,6 +127,12 @@ def load_json_body(self, request):
         except JSONDecodeError:
             return
 
+    def add_metric_tags(self, *args, **kwargs):
+        if not hasattr(self.request, '_metric_tags'):
+            self.request._metric_tags = {}
+
+        self.request._metric_tags.update(**kwargs)
+
     def initialize_request(self, request, *args, **kwargs):
         rv = super(Endpoint, self).initialize_request(request, *args, **kwargs)
         # If our request is being made via our internal API client, we need to
@@ -151,6 +157,10 @@ def dispatch(self, request, *args, **kwargs):
         self.request = request
         self.headers = self.default_response_headers  # deprecate?
 
+        # Tags that will ultimately flow into the metrics backend at the end of
+        # the request (happens via middleware/stats.py).
+        request._metric_tags = {}
+
         if settings.SENTRY_API_RESPONSE_DELAY:
             time.sleep(settings.SENTRY_API_RESPONSE_DELAY / 1000.0)
 

src/sentry/api/bases/sentryapps.py

@@ -33,6 +33,13 @@ def ensure_scoped_permission(request, allowed_scopes):
     return any(request.access.has_scope(s) for s in set(allowed_scopes))
 
 
+def add_integration_platform_metric_tag(func):
+    def decorator(self, *args, **kwargs):
+        self.add_metric_tags(integration_platform=True)
+        return func(self, *args, **kwargs)
+    return decorator
+
+
 class SentryAppsPermission(SentryPermission):
     scope_map = {
         'GET': (),  # Public endpoint.
@@ -58,7 +65,13 @@ def has_object_permission(self, request, view, organization):
         )
 
 
-class SentryAppsBaseEndpoint(Endpoint):
+class IntegrationPlatformEndpoint(Endpoint):
+    def dispatch(self, request, *args, **kwargs):
+        self.add_metric_tags(integration_platform=True)
+        return super(IntegrationPlatformEndpoint, self).dispatch(request, *args, **kwargs)
+
+
+class SentryAppsBaseEndpoint(IntegrationPlatformEndpoint):
     permission_classes = (SentryAppsPermission, )
 
     def convert_args(self, request, *args, **kwargs):
@@ -131,7 +144,7 @@ def _scopes_for_sentry_app(self, sentry_app):
             return self.unpublished_scope_map
 
 
-class SentryAppBaseEndpoint(Endpoint):
+class SentryAppBaseEndpoint(IntegrationPlatformEndpoint):
     permission_classes = (SentryAppPermission, )
 
     def convert_args(self, request, sentry_app_slug, *args, **kwargs):
@@ -175,7 +188,7 @@ def has_object_permission(self, request, view, organization):
         )
 
 
-class SentryAppInstallationsBaseEndpoint(Endpoint):
+class SentryAppInstallationsBaseEndpoint(IntegrationPlatformEndpoint):
     permission_classes = (SentryAppInstallationsPermission, )
 
     def convert_args(self, request, organization_slug, *args, **kwargs):
@@ -226,7 +239,7 @@ def has_object_permission(self, request, view, installation):
         )
 
 
-class SentryAppInstallationBaseEndpoint(Endpoint):
+class SentryAppInstallationBaseEndpoint(IntegrationPlatformEndpoint):
     permission_classes = (SentryAppInstallationPermission, )
 
     def convert_args(self, request, uuid, *args, **kwargs):

src/sentry/api/endpoints/organization_sentry_apps.py

@@ -1,12 +1,13 @@
 from __future__ import absolute_import
 
-from sentry.api.bases import OrganizationEndpoint
+from sentry.api.bases import OrganizationEndpoint, add_integration_platform_metric_tag
 from sentry.api.paginator import OffsetPaginator
 from sentry.api.serializers import serialize
 from sentry.models import SentryApp
 
 
 class OrganizationSentryAppsEndpoint(OrganizationEndpoint):
+    @add_integration_platform_metric_tag
     def get(self, request, organization):
         queryset = SentryApp.objects.filter(
             owner=organization,

src/sentry/api/endpoints/sentry_app_components.py

@@ -2,7 +2,9 @@
 
 from rest_framework.response import Response
 
-from sentry.api.bases import OrganizationEndpoint, SentryAppBaseEndpoint
+from sentry.api.bases import (
+    OrganizationEndpoint, SentryAppBaseEndpoint, add_integration_platform_metric_tag,
+)
 from sentry.api.paginator import OffsetPaginator
 from sentry.api.serializers import serialize
 from sentry.coreapi import APIError
@@ -21,6 +23,7 @@ def get(self, request, sentry_app):
 
 
 class OrganizationSentryAppComponentsEndpoint(OrganizationEndpoint):
+    @add_integration_platform_metric_tag
     def get(self, request, organization):
         try:
             project = Project.objects.get(

src/sentry/middleware/stats.py

@@ -27,6 +27,8 @@ class RequestTimingMiddleware(object):
     )
 
     def process_view(self, request, view_func, view_args, view_kwargs):
+        request._metric_tags = {}
+
         if request.method not in self.allowed_methods:
             return
 
@@ -56,13 +58,16 @@ def _record_time(self, request, status_code):
         if not hasattr(request, '_view_path'):
             return
 
+        tags = request._metric_tags if hasattr(request, '_metric_tags') else {}
+        tags.update({
+            'method': request.method,
+            'status_code': status_code,
+        })
+
         metrics.incr(
             'view.response',
             instance=request._view_path,
-            tags={
-                'method': request.method,
-                'status_code': status_code,
-            },
+            tags=tags,
             skip_internal=False,
         )
 

src/sentry/testutils/helpers/faux.py

@@ -174,6 +174,12 @@ def _kwargs_to_s(self, **kwargs):
         return ', '.join(u'{}={!r}'.format(k, v) for k, v in six.iteritems(kwargs))
 
 
+class Mock(object):
+    def __init__(self, *args, **kwargs):
+        for k, v in six.iteritems(kwargs):
+            setattr(self, k, v)
+
+
 def faux(mock, call=None):
     if call is not None:
         return Faux(mock.mock_calls[call])

tests/sentry/api/test_base.py

@@ -41,6 +41,15 @@ def test_basic_cors(self):
 
         assert response['Access-Control-Allow-Origin'] == 'http://example.com'
 
+    def test_add_metric_tags(self):
+        request = HttpRequest()
+        endpoint = DummyEndpoint()
+        endpoint.request = request
+
+        endpoint.add_metric_tags(foo='bar')
+
+        assert endpoint.request._metric_tags['foo'] == 'bar'
+
 
 class EndpointJSONBodyTest(APITestCase):
     def setUp(self):

tests/sentry/middleware/test_stats.py

@@ -0,0 +1,53 @@
+from __future__ import absolute_import
+
+from django.test import RequestFactory
+from exam import fixture
+from mock import patch
+
+from sentry.middleware.stats import RequestTimingMiddleware
+from sentry.testutils import TestCase
+from sentry.testutils.helpers.faux import Mock
+
+
+class RequestTimingMiddlewareTest(TestCase):
+    middleware = fixture(RequestTimingMiddleware)
+    factory = fixture(RequestFactory)
+
+    @patch('sentry.utils.metrics.incr')
+    def test_records_default_api_metrics(self, incr):
+        request = self.factory.get('/')
+        request._view_path = '/'
+        response = Mock(status_code=200)
+
+        self.middleware.process_response(request, response)
+
+        incr.assert_called_with(
+            'view.response',
+            instance=request._view_path,
+            tags={
+                'method': 'GET',
+                'status_code': 200,
+            },
+            skip_internal=False,
+        )
+
+    @patch('sentry.utils.metrics.incr')
+    def test_records_endpoint_specific_metrics(self, incr):
+        request = self.factory.get('/')
+        request._view_path = '/'
+        request._metric_tags = {'a': 'b'}
+
+        response = Mock(status_code=200)
+
+        self.middleware.process_response(request, response)
+
+        incr.assert_called_with(
+            'view.response',
+            instance=request._view_path,
+            tags={
+                'method': 'GET',
+                'status_code': 200,
+                'a': 'b',
+            },
+            skip_internal=False,
+        )