Health check api endpoints

trix/project/default/default_urls.py

@@ -12,5 +12,6 @@
     re_path(r'^admin/', admin.site.urls),
     re_path(r'^c/', include('trix.trix_course.urls')),
     re_path(r'^a/', include(CrAdminInstance.urls())),
+    re_path(r'^trix_core/', include('trix.trix_core.urls')),
     re_path(r'^', include('trix.trix_student.urls')),
 ]

trix/trix_core/api.py

@@ -0,0 +1,31 @@
+from django.db import connection
+from django.http import HttpResponse
+from django.views import View
+
+
+class ReadyCheck(View):
+    """
+    Is the application ready to accept connections?
+
+    Checks if it's possible to fetch from the database. This endpoint
+    should only be called until it returns 200.
+    NOTE: If it's needed to continously check if the application is alive,
+    use the "trix_core/_api/application-state/alive" endpoint.
+    Returns 200 OK response if ready, otherwise 503 is returned.
+    """
+    def get(self, request, *args, **kwargs):
+        with connection.cursor() as cursor:
+            cursor.execute("SELECT 1")
+            one = cursor.fetchone()[0]
+            if one != 1:
+                return HttpResponse(status=503)
+        return HttpResponse()
+
+
+class LiveCheck(View):
+    """
+    Check if application is "alive".
+    Returns 200 response.
+    """
+    def get(self, request, *args, **kwargs):
+        return HttpResponse()

trix/trix_core/urls.py

@@ -0,0 +1,8 @@
+from django.urls import re_path
+
+from .api import ReadyCheck, LiveCheck
+
+urlpatterns = [
+    re_path('_api/application-state/ready', ReadyCheck.as_view(), name='trix_core_application_state_ready'),
+    re_path('_api/application-state/alive', LiveCheck.as_view(), name='trix_core_application_state_alive'),
+]