Add Health Check endpoint (#392)

* add simple health endpoint

* add curl and healthcheck to dockerfile

* convert to view

* add simple test

* Add unhealthy test

* Cleanup

* check for LD_SERVER_PORT env var in healthcheck def

* Revert changes to middlewares.py

Co-authored-by: Sascha Ißbrücker <sascha.issbruecker@gmail.com>

bookmarks/tests/test_health_view.py

@@ -0,0 +1,36 @@
+from unittest.mock import patch
+
+from django.db import connections
+from django.test import TestCase
+
+from bookmarks.views.settings import app_version
+
+
+class HealthViewTestCase(TestCase):
+
+    def test_health_healthy(self):
+        response = self.client.get("/health")
+
+        self.assertEqual(response.status_code, 200)
+
+        response_body = response.json()
+        expected_body = {
+            'version': app_version,
+            'status': 'healthy'
+        }
+        self.assertDictEqual(response_body, expected_body)
+
+    def test_health_unhealhty(self):
+        with patch.object(connections['default'], 'ensure_connection') as mock_ensure_connection:
+            mock_ensure_connection.side_effect = Exception('Connection error')
+
+            response = self.client.get("/health")
+
+            self.assertEqual(response.status_code, 500)
+
+            response_body = response.json()
+            expected_body = {
+                'version': app_version,
+                'status': 'unhealthy'
+            }
+            self.assertDictEqual(response_body, expected_body)