Require fails when run in a process without stdin

Overview

I have a Linux 5.4 server which I am running a NodeJS expressjs app on. This app uses prom-client.

If I run the app in an interactive terminal everything works fine. However if I run the app in the background it crashes. If I remove require('prom-client') (and only this) my app works fine in the background.

It looks like prom-client is trying to read stdin on import, and is failing, thus crashing my process.

Expected Behavior

When I run my NodeJS application without any stdin (in a non-interactive terminal) it should work.

Actual Behavior

When I run my NodeJS application without any stdin it crashes with the error:

+ exec node index.js
hello world
events.js:291
       throw er; // Unhandled 'error' event
       ^
 Error: read ENOTCONN
     at tryReadStart (net.js:574:20) 
     at ReadStream.Socket._read (net.js:585:5)
     at ReadStream.Readable.read (_stream_readable.js:475:10)
     at ReadStream.Socket.read (net.js:625:39)
     at ReadStream.Socket (net.js:377:12)
     at new ReadStream (tty.js:58:14)
     at process.getStdin [as stdin] (internal/bootstrap/switches/is_main_thread.js:151:15)
     at get (<anonymous>)
     at getOwn (internal/bootstrap/loaders.js:150:5)
     at NativeModule.syncExports (internal/bootstrap/loaders.js:258:31)
	 Emitted 'error' event on ReadStream instance at:
     at emitErrorNT (internal/streams/destroy.js:100:8)
     at emitErrorCloseNT (internal/streams/destroy.js:68:3)
     at processTicksAndRejections (internal/process/task_queues.js:80:21) {
	 errno: -107,
	 code: 'ENOTCONN',
	 syscall: 'read'
}

Details

I have isolated the cause of the crash to require('prom-client'). If I don’t have this require statement in my app everything works fine.

Here is a 2 line self contained example.

It seems like the program is getting the error ENOTCONN on a read system call for the stdin file descriptor.

The fix to this error is to pipe some sort of stdin to the process in the background:

: | node index.js

[edwardofclt]

Came across this today and this solved my issue. Thanks for this.

[Noah-Huppert]

@zbjornson understandable I feel like something downstream from you is causing this issue. Hopefully the workarounds we’ve both posted will help anyone who comes across this from google 😃