"EADDRINUSE" error during smoke tests

[artem-zakharchenko]

Describe the bug
During the current Dredd's smoke tests there is an EADDRINUSE exception being thrown when trying to run dredd-example:

Listening on port 3000
events.js:186
      throw er; // Unhandled 'error' event
      ^

Error: listen EADDRINUSE: address already in use :::3000
    at Server.setupListenHandle [as _listen2] (net.js:1298:14)
    at listenInCluster (net.js:1346:12)
    at Server.listen (net.js:1434:7)
    at Function.listen (/home/circleci/project/dredd-example/node_modules/express/lib/application.js:618:24)
    at Object.<anonymous> (/home/circleci/project/dredd-example/app.js:216:5)
    at Module._compile (internal/modules/cjs/loader.js:936:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:947:10)
    at Module.load (internal/modules/cjs/loader.js:790:32)
    at Function.Module._load (internal/modules/cjs/loader.js:703:12)
    at Function.Module.runMain (internal/modules/cjs/loader.js:999:10)
Emitted 'error' event on Server instance at:
    at emitErrorNT (net.js:1325:8)
    at processTicksAndRejections (internal/process/task_queues.js:80:21) {
  code: 'EADDRINUSE',
  errno: 'EADDRINUSE',
  syscall: 'listen',
  address: '::',
  port: 3000
}

• Job example in CircleCI

To Reproduce
Perform a fresh CI build.

Expected behavior
I would expect smoke tests to not throw any exceptions and confirm Dredd usable.

---

Since this is happening for a while, I wonder if that's an expected behavior. I would appreciate @honzajavorek involvement in this discussion.

[honzajavorek]

This is a known issue of an unknown origin. Documented in apiaryio/dredd-example#36 and kind of in #1229 as well.

[honzajavorek]

I'll close this as duplicate, but it's definitely a valid bug report.