feat: implement graceful shutdown on sigterm (#728)

* feat: implement graceful shutdown on sigterm

* chore: address pr comments

Dockerfile

@@ -16,7 +16,8 @@ COPY --from=build /usr/src/app/node_modules node_modules
 COPY --from=build /usr/src/app/dist dist
 COPY package.json ./
 ENV PG_META_PORT=8080
-CMD ["npm", "run", "start"]
+# `npm run start` does not forward signals to child process
+CMD ["node", "dist/server/server.js"]
 EXPOSE 8080
 # --start-period defaults to 0s, but can't be set to 0s (to be explicit) by now
 HEALTHCHECK --interval=5s --timeout=5s --retries=3 CMD node -e "fetch('http://localhost:8080/health').then((r) => {if (r.status !== 200) throw new Error(r.status)})"

package.json

@@ -40,6 +40,7 @@
     "@fastify/swagger": "^8.2.1",
     "@fastify/type-provider-typebox": "^3.5.0",
     "@sinclair/typebox": "^0.31.25",
+    "close-with-grace": "^1.3.0",
     "crypto-js": "^4.0.0",
     "fastify": "^4.24.3",
     "fastify-metrics": "^10.0.0",

src/server/server.ts

@@ -1,3 +1,4 @@
+import closeWithGrace from 'close-with-grace'
 import { pino } from 'pino'
 import { PostgresMeta } from '../lib/index.js'
 import { build as buildApp } from './app.js'
@@ -125,7 +126,21 @@ if (EXPORT_DOCS) {
     })
   )
 } else {
-  app.listen({ port: PG_META_PORT, host: PG_META_HOST }, () => {
+  const closeListeners = closeWithGrace(async ({ err }) => {
+    if (err) {
+      app.log.error(err)
+    }
+    await app.close()
+  })
+  app.addHook('onClose', async () => {
+    closeListeners.uninstall()
+  })
+
+  app.listen({ port: PG_META_PORT, host: PG_META_HOST }, (err) => {
+    if (err) {
+      app.log.error(err)
+      process.exit(1)
+    }
     const adminPort = PG_META_PORT + 1
     adminApp.listen({ port: adminPort, host: PG_META_HOST })
   })