Merge pull request #283 from uktrade/add-simple-health-check

LTD-5658 Add simple health check

Pipfile

@@ -37,7 +37,7 @@ psycopg2-binary = "~=2.9.3"
 setuptools = "~=70.0.0"
 celery = "~=5.3.0"
 redis = "~=4.0.2"
-django-health-check = "~=3.17.0"
+django-health-check = "~=3.18.1"
 database-sanitizer = ">=1.1.0"
 factory-boy = "~=2.12.0"
 boto3 = "~=1.26.17"

conf/settings.py

@@ -50,19 +50,16 @@
     "django.contrib.staticfiles",
     "mail",
     "health_check",
+    "health_check.db",
+    "health_check.cache",
+    "health_check.storage",
+    "health_check.contrib.celery",
+    "health_check.contrib.celery_ping",
     "django_db_anonymiser.db_anonymiser",
     "healthcheck",
     "health_check.contrib.migrations",
 ]
 
-if not IS_ENV_DBT_PLATFORM:
-    INSTALLED_APPS += [
-        "health_check.db",
-        "health_check.cache",
-        "health_check.storage",
-        "health_check.contrib.celery",
-        "health_check.contrib.celery_ping",
-    ]
 
 MIDDLEWARE = [
     "django.middleware.security.SecurityMiddleware",

conf/urls.py

@@ -18,13 +18,14 @@
 from django.contrib import admin
 from django.urls import include, path
 
-from healthcheck.views import HealthCheckPingdomView
+from healthcheck.views import HealthCheckPingdomView, ServiceAvailableHealthCheckView
 
 urlpatterns = [
     path("admin/", admin.site.urls),
     path("mail/", include("mail.urls")),
     path("healthcheck/", include("health_check.urls")),
     path("pingdom/ping.xml", HealthCheckPingdomView.as_view(), name="healthcheck-pingdom"),
+    path("service-available-check/", ServiceAvailableHealthCheckView.as_view(), name="service-available-check"),
 ]
 
 if settings.ENABLE_MOCK_HMRC_SERVICE:  # pragma: no cover

healthcheck/tests/test_checks.py

@@ -9,7 +9,11 @@
 from health_check.exceptions import HealthCheckException
 from parameterized import parameterized
 
-from healthcheck.checks import LicencePayloadsHealthCheck, MailboxAuthenticationHealthCheck, PendingMailHealthCheck
+from healthcheck.checks import (
+    LicencePayloadsHealthCheck,
+    MailboxAuthenticationHealthCheck,
+    PendingMailHealthCheck,
+)
 from mail.enums import LicenceActionEnum, ReceptionStatusEnum
 from mail.models import LicencePayload, Mail
 

healthcheck/tests/test_healthcheck.py

@@ -63,3 +63,28 @@ def test_healthcheck_down(client, backends):
         b"</status><response_time>0.23</response_time>"
         b"</pingdom_http_custom_check>\n"
     )
+
+
+"""
+The tests below expect a 200 response whether healthchecks produce a healthy
+response or not as the url is used by DBT platform pipeline to check that
+the django app is alive.
+"""
+
+
+def test_service_available_check_broken(client, backends):
+    backends.reset()
+    backends.register(HealthCheckBroken)
+    url = reverse("service-available-check")
+    response = client.get(url)
+
+    assert response.status_code == 200
+
+
+def test_service_available_check_ok(client, backends):
+    backends.reset()
+    backends.register(HealthCheckOk)
+    url = reverse("service-available-check")
+    response = client.get(url)
+
+    assert response.status_code == 200

healthcheck/views.py

@@ -1,4 +1,6 @@
 from health_check.views import MainView
+from django.http import HttpResponse
+from rest_framework import status
 
 
 class HealthCheckPingdomView(MainView):
@@ -8,3 +10,11 @@ def render_to_response(self, context, status):
         context["errored_plugins"] = [plugin for plugin in context["plugins"] if plugin.errors]
         context["total_response_time"] = sum([plugin.time_taken for plugin in context["plugins"]])
         return super().render_to_response(context=context, status=status, content_type="text/xml")
+
+
+class ServiceAvailableHealthCheckView(MainView):
+    def get(self, request, *args, **kwargs):
+        return self.render_to_response()
+
+    def render_to_response(self):
+        return HttpResponse(status.HTTP_200_OK)