"Application failed to respond"

ikeguimaraes-dot

HOBBYOP

2 months ago

Service deploys successfully and internal healthcheck on /health passes, but the public domain returns "Application failed to respond".

App listens on 0.0.0.0, PORT=3000 set as service variable, domain configured to port 3000

Deploy logs confirm the app starts correctly (Nest application successfully started, routes mapped, DB connected)

Already tried: deleting and regenerating the domain, redeploying

Request ID: huyhjBtPRrqx8HGG5nX1uw

Builder: Dockerfile (migrated from Nixpacks)

$10 Bounty

2 Replies

Railway

BOT

2 months ago

This thread has been opened as a bounty so the community can help solve it.

Status changed to Open Railway • 2 months ago

2 months ago

Is your domain set to point to port 3000?

kellylemayianit

FREE

2 months ago

Missing EXPOSE Instruction: Without EXPOSE 3000 in your Dockerfile, the platform proxy may fall back to default exposed ports (like 80 or 8080) instead of routing to 3000.
- Hardcoded Port in NestJS: In NestJS main.ts, if app.listen() is hardcoded to 3000 rather than consuming process.env.PORT, any environment variable adjustments pushed by the edge proxy will be ignored.
- Port Misalignment Between App and Proxy: The service setting PORT=3000 sets an environment variable, but unless Docker explicitly exposes 3000 and NestJS listens on 0.0.0.0, the proxy router cannot bridge traffic across the container boundary.

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