From 44d9ef1195e3f55fbfac9b3eabc2e6d9b4ae3402 Mon Sep 17 00:00:00 2001
From: Harm Weites <harm@weites.com>
Date: Thu, 28 May 2020 14:17:56 +0200
Subject: [PATCH] Extremely simple /v1/health endpoint

Anonymous endpoint that may be used by a container platform to verify
availability of the application.

Simply returns: HTTP/200 {"status":"green"}

Future iterations could extend this into reflecting status of
dependencies like database connections.
---
 app/api/tests/test_api.py | 10 ++++++++++
 app/api/urls.py           |  3 ++-
 app/api/views.py          |  9 ++++++++-
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/app/api/tests/test_api.py b/app/api/tests/test_api.py
index 55303f74..5f8b08e7 100644
--- a/app/api/tests/test_api.py
+++ b/app/api/tests/test_api.py
@@ -29,6 +29,16 @@ def remove_all_role_mappings():
     RoleMapping.objects.all().delete()
 
 
+class TestHealthEndpoint(APITestCase):
+    @classmethod
+    def setUpTestData(cls):
+        cls.url = reverse(viewname='health')
+
+    def test_returns_green_status_on_health_endpoint(self):
+        response = self.client.get(self.url, format='json')
+        self.assertEqual(response.data['status'], 'green')
+
+
 class TestUtilsMixin:
     def _patch_project(self, project, attribute, value):
         old_value = getattr(project, attribute, None)
diff --git a/app/api/urls.py b/app/api/urls.py
index b6154c57..a8941b6d 100644
--- a/app/api/urls.py
+++ b/app/api/urls.py
@@ -2,7 +2,7 @@ from django.urls import path
 from rest_framework.authtoken.views import obtain_auth_token
 from rest_framework.urlpatterns import format_suffix_patterns
 
-from .views import Me, Features, Users
+from .views import Me, Features, Users, Health
 from .views import ProjectList, ProjectDetail
 from .views import LabelList, LabelDetail, ApproveLabelsAPI, LabelUploadAPI
 from .views import DocumentList, DocumentDetail
@@ -12,6 +12,7 @@ from .views import StatisticsAPI
 from .views import RoleMappingList, RoleMappingDetail, Roles
 
 urlpatterns = [
+    path('health', Health.as_view(), name='health'),
     path('auth-token', obtain_auth_token),
     path('me', Me.as_view(), name='me'),
     path('features', Features.as_view(), name='features'),
diff --git a/app/api/views.py b/app/api/views.py
index afa030f4..d081a08c 100644
--- a/app/api/views.py
+++ b/app/api/views.py
@@ -11,7 +11,7 @@ from libcloud.base import DriverType, get_driver
 from libcloud.storage.types import ContainerDoesNotExistError, ObjectDoesNotExistError
 from rest_framework import generics, filters, status
 from rest_framework.exceptions import ParseError, ValidationError
-from rest_framework.permissions import IsAuthenticated
+from rest_framework.permissions import IsAuthenticated, IsAuthenticatedOrReadOnly
 from rest_framework.response import Response
 from rest_framework.views import APIView
 from rest_framework.parsers import MultiPartParser
@@ -30,6 +30,13 @@ IsInProjectReadOnlyOrAdmin = (IsAnnotatorAndReadOnly | IsAnnotationApproverAndRe
 IsInProjectOrAdmin = (IsAnnotator | IsAnnotationApprover | IsProjectAdmin)
 
 
+class Health(APIView):
+    permission_classes = (IsAuthenticatedOrReadOnly,)
+
+    def get(self, request, *args, **kwargs):
+        return Response({'status': 'green'})
+
+
 class Me(APIView):
     permission_classes = (IsAuthenticated,)