Express app on Firebase Functions locally

Question

I created an Express app using Firebase Functions and am hosting the files on Firebase Hosting.

index.js (Firebase Functions):

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const express = require('express');
const parse = require('body-parser');
const cors = require('cors');

admin.initializeApp();

const app = express();

app.use(cors({ origin: true }));
app.use(parse.json());
app.use(parse.urlencoded({ extended: false }));

app.post('/create-url', (req, res) => {
    console.log(req.body);
    res.send(req.body);
});

exports.app = functions.https.onRequest(app);

firebase.json:

{
  "hosting": {
    "public": "public",
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**"
    ],
    "rewrites": [
      {
        "source": "**",
        "function": "app"
      }
    ]
  },
  "functions": {
    "predeploy": [
      "npm --prefix \"$RESOURCE_DIR\" run lint"
    ]
  },
  "emulators": {
    "functions": {
      "port": 5001
    },
    "firestore": {
      "port": 8080
    },
    "hosting": {
      "port": 5000
    },
    "ui": {
      "enabled": true,
      "port": 4000
    }
  }
}

When I make an HTTP request to http://localhost:5000/create-url, req.body is emtpy, but when I make a request to http://localhost:5001/PROJECT_NAME_HERE/us-central1/app/create-url (I've hidden the project name), it works properly. I'm using Postman to make the requests, but it isn't working with my front-end code either :(. If I deploy to Hosting and Functions and access the app through the web.app domain, it works. I'm running firebase emulators:start to run locally.

Thanks in advance for your help!

Answer 1

Check out the bottom section of this page https://firebase.google.com/docs/emulator-suite/install_and_configure. 'Generate an auth token (Hosting emulator only)'.

Basically you have to generate an auth token and pass it as a flag in your build script or add it to your ci environment variables.

Let me know if it helps!