Why does firebase hosting return a complete html response for a request on a non existing resources?

Question

My question is about the unexpected response from the firebase hosting server for non existing resources.

In my case the static index.html references a css file with <link rel="stylesheet" href="main.css">. This file does not exist on the firebase hosting server. Therfore I would have expected the server to respond with the status code 404. But the server returns a complete html document instead:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Welcome to Firebase Hosting</title>

<!-- update the version number as needed -->
<script defer src="/__/firebase/4.12.1/firebase-app.js"></script>
<!-- include only the Firebase features as you need -->
<script defer src="/__/firebase/4.12.1/firebase-auth.js"></script>
<script defer src="/__/firebase/4.12.1/firebase-database.js"></script>
<script defer src="/__/firebase/4.12.1/firebase-messaging.js"></script>
<script defer src="/__/firebase/4.12.1/firebase-storage.js"></script>
<!-- initialize the SDK after all desired features are loaded -->
<script defer src="/__/firebase/init.js"></script>

<style media="screen">
  body { background: #ECEFF1; color: rgba(0,0,0,0.87); font-family: Roboto, Helvetica, Arial, sans-serif; margin: 0; padding: 0; }
  #message { background: white; max-width: 360px; margin: 100px auto 16px; padding: 32px 24px; border-radius: 3px; }
  #message h2 { color: #ffa100; font-weight: bold; font-size: 16px; margin: 0 0 8px; }
  #message h1 { font-size: 22px; font-weight: 300; color: rgba(0,0,0,0.6); margin: 0 0 16px;}
  #message p { line-height: 140%; margin: 16px 0 24px; font-size: 14px; }
  #message a { display: block; text-align: center; background: #039be5; text-transform: uppercase; text-decoration: none; color: white; padding: 16px; border-radius: 4px; }
  #message, #message a { box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24); }
  #load { color: rgba(0,0,0,0.4); text-align: center; font-size: 13px; }
  @media (max-width: 600px) {
    body, #message { margin-top: 0; background: white; box-shadow: none; }
    body { border-top: 16px solid #ffa100; }
  }
</style>
</head>
<body>
<div id="message">
  <h2>Welcome</h2>
  <h1>Firebase Hosting Setup Complete</h1>
  <p>You're seeing this because you've successfully setup Firebase Hosting. Now it's time to go build something extraordinary!</p>
  <a target="_blank" href="https://firebase.google.com/docs/hosting/">Open Hosting Documentation</a>
</div>
<p id="load">Firebase SDK Loading&hellip;</p>

<script>
  document.addEventListener('DOMContentLoaded', function() {
    // // ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
    // // The Firebase SDK is initialized and available here!
    //
    // firebase.auth().onAuthStateChanged(user => { });
    // firebase.database().ref('/path/to/ref').on('value', snapshot => { });
    // firebase.messaging().requestPermission().then(() => { });
    // firebase.storage().ref('/path/to/ref').getDownloadURL().then(() => { });
    //
    // // ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

    try {
      let app = firebase.app();
      let features = ['auth', 'database', 'messaging', 'storage'].filter(feature => typeof app[feature] === 'function');
      document.getElementById('load').innerHTML = `Firebase SDK loaded with ${features.join(', ')}`;
    } catch (e) {
      console.error(e);
      document.getElementById('load').innerHTML = 'Error loading the Firebase SDK, check the console.';
    }
  });
</script>
</body>
</html>

Is it possible to configure firebase hosting to return the status code 404 instead of html?

abraham abraham · Accepted Answer · 2018-04-12T15:50:03

Check your firebase.json for a ** rewrite.

{
  "hosting": {
    "public": "public",
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**"
    ],
    "rewrites": [
      {
        "source": "**",
        "destination": "/index.html"
      }
    ]
  }
}

The ** rewrite says any request not matching a rule before it should get index.html served to it. It is designed for Singe Page Apps like Angular that have a single index.html page for rendering all pages. If you don't want that behavior you can replace the rewrite with rules more specific to your needs.

Why does firebase hosting return a complete html response for a request on a non existing resources?

1 Answers