[WIP] Sentry improvements (#108)

Stator clears scope during the main loop to behave more like
transactions. Transaction names are set.

Sentry tags:
* 'takahe.version'
* 'takahe.app' values 'web' or 'stator'

Added settings:
* TAKAHE_SENTRY_SAMPLE_RATE
* TAKAHE_SENTRY_TRACES_SAMPLE_RATE

1 files changed, 19 insertions, 0 deletions

diff --git a/core/middleware.py b/core/middleware.py
index fca5dd8..08c28fa 100644
--- a/core/middleware.py
+++ b/core/middleware.py
@@ -1,3 +1,6 @@
+from django.core.exceptions import MiddlewareNotUsed
+
+from core import sentry
 from core.models import Config
 
 
@@ -13,3 +16,19 @@ class ConfigLoadingMiddleware:
         Config.system = Config.load_system()
         response = self.get_response(request)
         return response
+
+
+class SentryTaggingMiddleware:
+    """
+    Sets Sentry tags at the start of the request if Sentry is configured.
+    """
+
+    def __init__(self, get_response):
+        if not sentry.SENTRY_ENABLED:
+            raise MiddlewareNotUsed()
+        self.get_response = get_response
+
+    def __call__(self, request):
+        sentry.set_takahe_app("web")
+        response = self.get_response(request)
+        return response