Direct Firebase Hosting to Cloud Functions deployed in other regions

Question

I updated the Firebase hosting rule following this document so I can have the cloud function end point using my own domain name. However it seems this only applies to the cloud function deployed in the default region in us-central1.

"hosting": {
 "rewrites": [ {
   "source": "/endpoint",
   "function": "app"
 } ]
}

But whenever my functions are deployed like the following, the aforementioned the custom domain no longer works because it would still forward the requests to us-central1 rather than asia-east2 resulting in a 403 error.

functions.region('asia-east2').https.onRequest((request, response) => {
    response.send("Hello from Firebase!");
});

Does anyone know how this issue could be fixed? Many thanks!

It seems like functions for Firebase Hosting are intended to serve dynamic content for Firebase CDN which sources from us-central1. If what you require is a custom domain connecting to the function and do not tightly relied on Firebase CDN, I think you can give Cloudflare a try, setting CNAME on Cloudflare linking to the domain of your funciton in another region. Though not testing yet myself, I'm also finding a solution to this. — momocow
Ok, I find out that CNAME won't work. No need to try. stackoverflow.com/a/61969054/8579025 — momocow

Doug Stevenson Doug Stevenson · Accepted Answer · 2020-07-12T16:01:57

The behavior you're observing is expected, and documented. From the Firebase Hosting documentation:

Important: Firebase Hosting supports Cloud Functions in us-central1 only.

Direct Firebase Hosting to Cloud Functions deployed in other regions

1 Answers