Add basic django metrics (#453)

myhpi/core/markdown/extensions.py

@@ -1,4 +1,5 @@
 import re
+import xml.etree.ElementTree
 
 from django.core.exceptions import ObjectDoesNotExist
 from django.utils.translation import gettext_lazy as _
@@ -145,7 +146,7 @@ def decrease(self, match):
 
 class InternalLinkPattern(LinkInlineProcessor):
     def handleMatch(self, m, data=None):
-        el = util.etree.Element("a")
+        el = xml.etree.ElementTree.Element("a")
         try:
             el.set("href", self.url(m.group("id")))
             el.text = util.AtomicString(m.group("title"))

myhpi/core/urls.py

@@ -1 +1,5 @@
-urlpatterns = []
+from django.urls import path
+
+from myhpi.core.views import metrics_view
+
+urlpatterns = [path("metrics", metrics_view, name="prometheus-django-metrics")]

myhpi/core/views.py

@@ -1 +1,13 @@
 # Create your views here.
+import prometheus_client
+from django.conf import settings
+from django.http import HttpResponse
+
+
+def metrics_view(request):
+    provided_key = request.headers.get("X-API-KEY")
+    if provided_key and provided_key == settings.METRICS_API_KEY:
+        metrics_page = prometheus_client.generate_latest(prometheus_client.REGISTRY)
+        return HttpResponse(metrics_page, content_type=prometheus_client.CONTENT_TYPE_LATEST)
+    else:
+        return HttpResponse("Unauthorized", status=401)

myhpi/settings.py

@@ -64,6 +64,7 @@
     "myhpi.polls",
     "myhpi.search",
     "static_precompiler",
+    "django_prometheus",
 ]
 
 AUTHENTICATION_BACKENDS = [
@@ -93,6 +94,7 @@
 LOGIN_URL = "login"
 
 MIDDLEWARE = [
+    "django_prometheus.middleware.PrometheusBeforeMiddleware",
     "django.contrib.sessions.middleware.SessionMiddleware",
     "django.middleware.common.CommonMiddleware",
     "django.middleware.csrf.CsrfViewMiddleware",
@@ -104,6 +106,7 @@
     "wagtail.contrib.redirects.middleware.RedirectMiddleware",
     "myhpi.core.middleware.IPRangeUserMiddleware",
     "mozilla_django_oidc.middleware.SessionRefresh",
+    "django_prometheus.middleware.PrometheusAfterMiddleware",
 ]
 
 if DJANGO_DEBUG:
@@ -308,11 +311,15 @@
 SERVER_EMAIL = env.str("SERVER_EMAIL")
 ADMINS = getaddresses(env.list("ADMINS"))
 
+# Set this to view /metrics with X-API-KEY header
+METRICS_API_KEY = env.str("METRICS_API_KEY", default=None)
+
+# logging
+
 LOG_DIR = os.path.join(BASE_DIR, "logs")
 if not os.path.exists(LOG_DIR):
     os.makedirs(LOG_DIR)
 
-# logging
 LOGGING = {
     "version": 1,
     "disable_existing_loggers": False,

myhpi/tests/core/test_metrics.py

@@ -0,0 +1,13 @@
+from myhpi.tests.core.utils import MyHPIPageTestCase
+
+
+class MetricsTests(MyHPIPageTestCase):
+    def test_unauthorized_metrics(self):
+        with self.settings(METRICS_API_KEY="TEST_KEY"):
+            response = self.client.get("/metrics")
+            self.assertEqual(response.status_code, 401)
+
+    def test_authorized_metrics(self):
+        with self.settings(METRICS_API_KEY="TEST_KEY"):
+            response = self.client.get("/metrics", **{"HTTP_X-API-KEY": "TEST_KEY"})
+            self.assertEqual(response.status_code, 200)

myhpi/tests/settings.py

@@ -3,3 +3,5 @@
 DEBUG = True
 STATICFILES_STORAGE = "django.contrib.staticfiles.storage.StaticFilesStorage"
 WAGTAIL_APPEND_SLASH = False
+
+METRICS_API_KEY = "TEST_KEY"

myhpi/urls.py

@@ -31,6 +31,7 @@
         ".well-known/security.txt",
         RedirectView.as_view(url=os.path.join(settings.STATIC_URL, "security.txt")),
     ),
+    path("", include("myhpi.core.urls")),
 ]
 
 

pyproject.toml

@@ -21,6 +21,7 @@ html2text = "^2020.1.16"
 wagtail-markdown = "^0.11.1"
 autoflake = "^2.2.1"
 setuptools-scm = "^8.0.4"
+django-prometheus = "^2.3.1"
 
 [tool.poetry.group.dev.dependencies]
 pylint = "^3.0.3"