I have a REST api that list me all files in a bucket. I show this list in a webview on a ios device.
It's not possible to make this file public.
So to my question, how can i access the files in my ios app?
My idea is, i create a read stream in my api that open a read stream to the file in the gcloud bucket.
Is there a better way to do this?
The canonical way to expose a private file is to used signed URLs. Basically, your iOS app would request access to a file from your app. If your app decides to grant this access, it generates a URL, signs it with a private key, and then provides that signed URL to the iOS app. The app then fetches the URL provided like any other URL, the body of which will be the object's contents.
Signed URLs have some nice security advantages. They can only be used for exactly one thing, and they're only valid for a few minutes (you can configure exactly how long they're valid).
The signing logic is a little tricky, but the gcloud libraries have functions to sign URLs for you.
Documentation is here: https://cloud.google.com/storage/docs/access-control/signed-urls
