Add metrics for request/task counting

src/pretix/helpers/metrics/middleware.py

@@ -0,0 +1,30 @@
+from django.urls import resolve
+
+from pretix.base.metrics import http_view_requests
+
+
+class MetricsMiddleware(object):
+    blacklist = (
+        '/healthcheck/',
+        '/jsi18n/',
+        '/metrics',
+    )
+
+    def __init__(self, get_response):
+        self.get_response = get_response
+        # One-time configuration and initialization.
+
+    def __call__(self, request):
+        # Code to be executed for each request before
+        # the view (and later middleware) are called.
+        for b in self.blacklist:
+            if b in request.path:
+                return self.get_response(request)
+
+        url = resolve(request.path_info)
+
+        resp = self.get_response(request)
+        http_view_requests.inc(1, status_code=resp.status_code, method=request.method,
+                               url_name=url.namespace + ':' + url.url_name)
+
+        return resp