Скачать или смотреть Understanding Firebase Hosting URL Rewrites for Cloud Run Integration

Discover how to effectively manage path rewrites in Firebase Hosting to route requests to `Cloud Run` services, and learn what limitations you might encounter.
---
This video is based on the question https://stackoverflow.com/q/63964661/ asked by the user 'Pablote' ( https://stackoverflow.com/u/60810/ ) and on the answer https://stackoverflow.com/a/63965521/ provided by the user 'Doug Stevenson' ( https://stackoverflow.com/u/807126/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Firebase Hosting: is it possible to rewrite a URL and pass part of the path to Cloud Run?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Solving the Firebase Hosting and Cloud Run URL Rewrite Challenge

In the world of cloud computing, seamlessly integrating different services can often feel overwhelming. One common challenge developers face is figuring out how to properly route requests when using Firebase Hosting in front of Cloud Run. If you're looking to append an API in your Firebase setup under an /api prefix and want those requests to correctly forward to your Cloud Run service, you’re in the right place. Let’s dive into this issue to clarify the process and understand the limitations.

The Problem: Routing Requests Correctly

Imagine you have an API deployed on Cloud Run, and you want to expose it through Firebase Hosting. Your goal is to receive a request at a URL like /api/something and have that routed to your API handler so that /something is invoked correctly. However, after multiple attempts at creating rewrites in your Firebase configuration, you find that it’s not working as expected. This leaves you with a couple of questions:

How do you route endpoints prefixed with /api to the correct handler in Cloud Run?

Is there a way to strip the /api prefix or utilize the captured portions of the path while routing?

The Solution: Understanding URL Management with Firebase Hosting

Initial Attempts at Rewrites

Basic Rewrite Setup:
Your first approach was to set up a simple rewrite rule in your firebase.json configuration:

[[See Video to Reveal this Text or Code Snippet]]

This configuration correctly routed /api requests to the service root but failed when you tried to access /api/something, leading to a 404 error.

Wildcard and Regex Attempts:
Your second strategy involved utilizing wildcards or regular expressions:

[[See Video to Reveal this Text or Code Snippet]]

or

[[See Video to Reveal this Text or Code Snippet]]

This successfully matched requests like /api/something but redirected them to the root of your API instead of stripping the /api prefix and directing requests to /something.

Understanding the Limitation

Unfortunately, as per the structure and functionality of Firebase Hosting, there’s a core limitation: the full URI of the request is preserved when it is sent to Cloud Run. This means that no matter how much you attempt to manipulate the routing structure within Firebase, you cannot directly strip path prefixes like /api during the forwarding process.

Handling the Routing Logic on Cloud Run

Given this constraint, the solution lies in adjusting the code deployed to your Cloud Run service. Here’s how you can manage it:

Code Logic: Write logic in your Cloud Run application to handle the incoming request paths directly. For instance, if the request comes in as /api/something, modify your code to recognize the /api prefix and route accordingly.

Extracting the Path Component: Use string manipulation methods within your programming language of choice to discard the prefix. For example, if you're using Node.js, you might write:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

While the desire to directly manipulate incoming request paths within Firebase Hosting is understandable, it’s important to adapt your approach based on the limitations of the infrastructure. By handling the request path logic in your Cloud Run service, you can effectively manage your API routing as needed.

With this framework, you can now confidently set up your Firebase Hosting and Cloud Run integration without running into the infamous 404 error for your API endpoints.

If you have further questions or require clarification on this topic, don’t hesitate to reach out!