How to deploy a Fastify app

Fastify listens on localhost by default, which means it is unreachable on a hosted server. To deploy it on Schokr, pass host: '0.0.0.0' and your allocated port to fastify.listen().

1. Write your server#

server.js:

import Fastify from 'fastify'

const app = Fastify({ logger: true })

app.get('/', async () => ({ status: 'ok' }))

const port = Number(process.env.APP_PORT || 3000)

try {
  await app.listen({ host: '0.0.0.0', port })
} catch (err) {
  app.log.error(err)
  process.exit(1)
}

package.json:

{
  "name": "my-fastify-app",
  "type": "module",
  "main": "server.js",
  "scripts": { "start": "node server.js" },
  "dependencies": { "fastify": "^5.0.0" }
}

Fastify 5 needs Node.js 20 or newer. If your server runs an older Node.js version, use Fastify 4 or check whether your server's Startup settings let you pick a newer version.

2. Deploy on Schokr#

1. Create a server with the Node.js template in the console.
2. Note the port in the Network section.
3. Upload server.js, package.json and package-lock.json with the file manager. Do not upload node_modules.
4. Put the port in a .env file (APP_PORT=<your-port>) and start Node with --env-file=.env, or use the dotenv package. See environment variables.
5. Set the main file to server.js in your server's Startup settings.
6. Start the server.

3. Check the logs#

With logger: true, Fastify prints a JSON line when it is ready:

{"level":30,"msg":"Server listening at http://0.0.0.0:25571"}

If you see 127.0.0.1 there instead, the host option is not being applied. Open http://<server-address>:<port> to test.

Useful plugins#

Behind a proxy#

If you place a reverse proxy or Cloudflare in front of your app, enable trustProxy so client IPs are read from the forwarded headers:

const app = Fastify({ logger: true, trustProxy: true })

Troubleshooting#

• EADDRINUSE: another process or a second listen call is using the port. See port errors.
• ERR_REQUIRE_ESM or Cannot use import statement outside a module: add "type": "module" to package.json, or use require syntax.
• Crashes on start: see app crashes on start.