Firebase iOS SDK authentication with private Google storage

Question

I am testing out using the Firebase SDK for iOS/macOS in my app (macOS app). i have installed the SDK´s using:

pod 'FirebaseCore', :git => 'https://github.com/firebase/firebase-ios-sdk.git', :tag => '4.8.2'
pod 'FirebaseAuth', :git => 'https://github.com/firebase/firebase-ios-sdk.git', :tag => '4.8.2'
pod 'FirebaseStorage', :git => 'https://github.com/firebase/firebase-ios-sdk.git', :tag => '4.8.2' 

The installation works well and I can configure my app in AppDelegate using [FIRApp configure];

I wonder if I can use the SDK to log in the user to his/hers private Google Cloud storage (GCS)? I understand I can use the SDK for storing to GCS in the apps storage, but it would be nice to log in to the users own GCS to retrieve a list of buckets and files. If anyone has an example as for how to do this I would appreciate it. All examples I find are for anonymous storage logins.

Update: I could specify that I was hoping that Firebase SDK would contain an authentication method that allowed me access to my own Google cloud storage account. Perhaps Firebase is not the right choice for this, but then I would be very interested in suggestions for alternative SDKs for Swift/objective-c login/upload/download to Google cloud storage.

Answer 1

You can indeed use the Firebase SDK for iOS to work with Firebase Cloud Storage (which in fact stores data in Google Cloud Platform Cloud Storage's buckets), using both Swift and Objective-C.

Firebase Cloud Storage in iOS

Regarding the usage of Cloud Storage buckets in your Firebase application, you can get started with this documentation page. First of all, you have to set up the proper security rules to the bucket: you can allow public access, access to only authenticated users, or even per-userID access. There are some sample rules that you can use to start working with this.

Once you have set up the appropriate access for Storage buckets (if each user has its own bucket, then I assume each user will have a GCP account with a private bucket and they will have to set up the configuration access themselves, as you will not have access to them), you can add the Cloud Storage dependencies to your iOS app:

pod 'Firebase/Core'
pod 'Firebase/Storage'

Then run pod install and you can already create the reference to Cloud Storage after initializing Firebase in your app (here you have a Swift sample code, but you can have a look at the Objective-C samples in the documentation too):

// Import and set up Firebase
import Firebase
FirebaseApp.configure()

// Create a storage reference
let storage = Storage.storage()
let storageRef = storage.reference()

// Refer to a child directory or even a file
let folderRef = storageRef.child("my_folder")
var fileRef = folderRef.child("my_file.txt")

And once you have all this, you can proceed to more complex guides, such as uploading files, downloading files or (important) handling errors. Bear in mind that these are just some examples of the things you can do following the step-by-step documentation, but feel free to move through all the pages in order to have a deeper understanding about how all this works.

Firebase Authentication for Cloud Storage in iOS

Also, regarding authentication, you can follow the same rules that you are probably already using for the rest of your Firebase application. Let me share this other page talking about some mechanisms to provide Firebase Authentication, and specifically how to provide Firebase Authetication on iOS.

Answer 2

I'm not sure I fully understand what you're asking. But if I do... This may help. I've used Google Storage to save photos. To access those photos I needed to store the URL to locate those photos. I did this in the Firebase Realtime Database. If you store a different type of file to a GCS, all you need is that URL to retrieve the data.

if let photoData = UIImageJPEGRepresentation(jpegRepresentation!, 1.0) {
                    storePhoto(photoData, angel.name!, completion: { (url, err) in
                        if err != nil {
                            print(err?.localizedDescription)
                            angelToSave["photo"] = nil
                            myAngelsRef.updateChildValues(angelToSave, withCompletionBlock: { (error, ref) in
                                if error != nil {
                                    completion(error!)
                                } else {
                                    completion(nil)
                                }
                            })
                        } else {
                                  // ### HERE ####
                            angelToSave["photo"] = url?.absoluteString
                            angelNameRef.updateChildValues(angelToSave)
                            completion(nil)
                        }
                    })
                }

func storePhoto(_ photo: Data, _ name: String, completion: @escaping (_ result: URL?, _ error: NSError?) -> Void) {
        let storageRef = Storage.storage().reference().child(name)
        storageRef.putData(photo, metadata: nil) { (storageMetaData, err) in
            if err != nil {
                completion(nil, NSError(domain: (err?.localizedDescription)!, code: 0, userInfo: nil))
            } else {
                completion(storageMetaData?.downloadURL(), nil)
            }
        }
    }

After I saved the photo I was able to get the URL location and save that to an object I stored in the RTDB. Now when I pull the data from the use's RTDB I get the URL for the Storage data.