How to list all files that are in GCP bucket behind an external load balancer

Question

I have a load balancer with 2 buckets as a backend. Let's call them bucket1 and bucket2. The structure of these buckets is similar and looks like this:

• dir1
• dir1/subdir1
• dir1/subdir2
• ...
• dir2/subdir1
• ...

Every subdirx has multiple files.

I want to use the load balancer that has a static IP to:

1. List all the files in the bucket (full paths)
2. Get a file

Any idea how to achieve (1)? How should I structure the rules and the paths of my LoadBalancer? Any help is more than appreciated. Thanks in advance.