Port is hard coded to 8081 on iOS, Android templates

[jdmarshall]

The documentation on working around port conflict issues is no longer valid

https://facebook.github.io/react-native/docs/troubleshooting.html

Mentions the command line and the URL in AppDelegate.m (which has changed to a function call now)
but does not mention that

node_modules/react-native/React/React.xcodeproj/project.pbxproj

has 8081 hard-coded

Also, to be perfectly blunt, telling people to kill their virus scanner is negligent behavior. We need a solution that doesn't involve asking people to turn off safety features their organization mandated that they use. Especially when you have a company name attached to that advice.

[hramos]

Terminating the process that is using the port is one alternative that is provided, followed with instructions to use a different port which would be a better solution.

Can you edit https://github.com/facebook/react-native/blob/master/docs/Troubleshooting.md with the latest instructions and submit a PR?

[jdmarshall]

I can't, because I can't get it to work. Short of searching the entire node_modules directory for instances of 8081 and changing them, because there are new spots that were hard coded after these instructions were written, and there is no obvious way to override them

[jdmarshall]

react-native/local-cli/server/server.js

Takes an override, but at least most of these below seem to ignore it:

react-native/React/Base/RCTBundleURLProvider.m
react-native/Libraries/WebSocket/RCTWebSocketExecutor.m
react-native/React/React.xcodeproj/project.pbxproj

The others I could probably sort out, despite not being an Objective C programmer, but the last one seems to be new and I don't have the foggiest how to pass in the port as a parameter:

react-native/React/React.xcodeproj/project.pbxproj

shellScript = "if nc -w 5 -z localhost 8081 ; then...

[perkola]

These files below also seem to have port 8081 hard-coded in some places.

react-native/ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/AndroidInfoHelpers.java
react-native/packager/react-packager/src/Server/__tests__/Server-test.js
react-native/local-cli/util/isPackagerRunning.js
react-native/Libraries/Image/__tests__/resolveAssetSource-test.js

[perkola]

Does this classify as a bug? Or how do i set a custom port that actually works?

[perkola]

Bump. This seems to be a problem with Android as well. Starting the packager on a different port with react-native start --port 8082 worked on v.0.26.* but no longer works on v.0.30.0.

[MichaelCereda]

This bug should be treated with with high priority, port 8081 is used by some process like McAfee.
Changing the default port should be easy and painless.

[satya164]

@MichaelCereda If this is a high priority issue for you, consider sending a PR to fix it.

[jdmarshall]

I have some deep philosophical problems with suggesting that a feature that mostly affects new users should be fixed in a PR by those new users.

By all means, let's get esoteric feature requests to file their own PRs. But it comes off as flippant when it's a feature brand new users run into before they even decide if they want to be part of the ecosystem.

(It's especially grating when that bug is a port conflict. Is this 1996 or 2016?)

[MichaelCereda]

By now the fastest solution is to kill the process (in my case McAfee) and face the web like a real man.
I always find interesting those type of comments because I have hard time understand if they are a sort of life coaching aimed at the self improvement or mere trolling.

As @jdmarshall said, I think that is an high priority fix because it discourages new users to adopt react-native that is a framework that I personally love.
Submitting a PR it's possible but at the same time would require centralize the port number under one configuration file., the problem with this approach is that RN currently uses 3 different environments that should in many ways be independent from external files (that's why the port number has always been hard-coded in at least 2 places).
The only problem is my opinion that the port RN is using is the 8081 that is one of the most common ever and the risk of conflict is high.
I'll try to find a solution but suggestions from the team will be highly appreciated.