how to connect to localhost Meteor app

[jankapunkt]

I am using expo and I am trying to connect to a Meteor app on localhost in dev mode (expo start; bundle is pushed to my real android phone, no emulator)

Meteor.connect('ws://localhost:8080/websocket')
Meteor.getData().ddp.socket.rawSocket.onerror = e => console.error(e);
Meteor.getData().ddp.socket.addListener("open", () => console.log("open"));
Meteor.getData().ddp.socket.addListener("close", () => console.log("close"));

which produces the following output:

close
close

Event {
  "isTrusted": false,
  "message": "Failed to connect to localhost/127.0.0.1:8080",
}
at meteor/connect.js:12:2 in connectMeteor
at node_modules/react-native/Libraries/WebSocket/WebSocket.js:258:8 in _eventEmitter.addListener$argument_1
at node_modules/react-native/Libraries/vendor/emitter/_EventEmitter.js:135:10 in EventEmitter#emit

Dependencies:

    "@babel/preset-react": "^7.16.0",
    "@expo/vector-icons": "^12.0.5",
    "@meteorrn/core": "^2.3.0",
    "@react-native-community/netinfo": "^7.1.7",
    "@react-navigation/native": "^6.0.6",
    "@react-navigation/native-stack": "^6.2.5",
    "@react-navigation/stack": "^6.0.11",
    "babel-preset-es2015": "^6.24.1",
    "colors": "1.4.0",
    "expo": "~43.0.3",
    "expo-app-loading": "^1.2.1",
    "expo-font": "~10.0.3",
    "expo-speech": "~10.0.3",
    "expo-splash-screen": "~0.13.5",
    "i18next": "^21.5.4",
    "react": "17.0.2",
    "react-dom": "17.0.2",
    "react-i18next": "^11.14.3",
    "react-native": "^0.64.3",
    "react-native-elements": "^3.4.2",
    "react-native-gesture-handler": "^1.10.3",
    "react-native-safe-area-context": "3.3.2",
    "react-native-screens": "~3.8.0",
    "react-native-tts": "^4.1.0",
    "react-native-vector-icons": "^9.0.0",
    "react-native-web": "~0.17.5"

Is this expected; did I do something wrong here?

[TheRealNate]

Hey @jankapunkt, if you're pushing the bundle to a physical device localhost will not be accessible as localhost is only available on the same device the Meteor app is being run from. Your best bet is to locate the LAN IP address (https://en.wikipedia.org/wiki/Private_network#Private_IPv4_addresses) for your machine running Meteor and connect to that. For example: ws://192.168.1.123:8080/websocket (that IP address is completely made up, you'll need to find the correct one for your machine).

Here is a StackOverflow question on this: https://stackoverflow.com/questions/47417766/calling-locally-hosted-server-from-expo-app. They have a different route where they dynamically access the IP address of your machine. It is up to you which option you prefer.

I'm removing the bug tag as I don't believe at this time that this is related to an issue with this package, however I will leave the issue open for now. Please close if you're able to solve your problem.

[jankapunkt]

Hi thank you yes that fixed it. I would add this to the documentation as a PR so others won't jump into that trap, what do you think?

[TheRealNate]

@jankapunkt absolutely agree. I'll add some more details soon but for now I've added a link to this issue in the README under Basic Usage. I'll also close this issue.