Merge pull request #12994 from github/repo-sync

repo sync

Author: Octomerger

middleware/healthz.js

@@ -0,0 +1,20 @@
+import express from 'express'
+
+const router = express.Router()
+
+/**
+ * Returns the healthiness of the service.
+ * This may be used by azure app service (forthcoming) to determine whether this
+ * instance remains in the pool to handle requests
+ * For example: if we have a failing database connection we may return a 500 status here.
+ */
+router.get('/', function healthz(req, res, next) {
+  res.set({
+    'surrogate-control': 'private, no-store',
+    'cache-control': 'private, no-store',
+  })
+
+  res.sendStatus(200)
+})
+
+export default router

middleware/index.js

@@ -38,6 +38,7 @@ import blockRobots from './block-robots.js'
 import archivedEnterpriseVersionsAssets from './archived-enterprise-versions-assets.js'
 import events from './events.js'
 import search from './search.js'
+import healthz from './healthz.js'
 import archivedEnterpriseVersions from './archived-enterprise-versions.js'
 import robots from './robots.js'
 import earlyAccessLinks from './contextualizers/early-access-links.js'
@@ -182,6 +183,7 @@ export default function (app) {
   // *** Rendering, 2xx responses ***
   app.use('/events', asyncMiddleware(instrument(events, './events')))
   app.use('/search', asyncMiddleware(instrument(search, './search')))
+  app.use('/healthz', asyncMiddleware(instrument(healthz, './healthz')))
 
   // Check for a dropped connection before proceeding (again)
   app.use(haltOnDroppedConnection)