AWS iOS SDK AWSServiceManager multiple service configurations - ios

Question

I've integrated the AWS iOS SDK (v.2.3.6) into my application. It works fine and good, except that I've noticed that defaultServiceManager has a disclaimer:
"You should use this singleton method instead of creating an instance of the service manager".
I ordinarily wouldn't have an issue with this, except it's defaultServiceConfiguration is immutable:
"This property can be set only once, and any subsequent setters are ignored."
I have a requirement that a service configuration (ie. identityPoolId + region) be able to change at runtime.
What are the possible ways around this? I'd love to be able to just reset the service configuration at any point, but that's unlikely given what the documentation says.

Answer 1

You should not mutate the default service configuration. Instead, each service client provides the following class methods:
+ register[ServiceClientName]WithConfiguration:forKey:
+ [ServiceClientName]ForKey:
For example, for AWSS3TransferUtility, they are:
+ registerS3TransferUtilityWithConfiguration:forKey:
+ S3TransferUtilityForKey:
In this way, you can pass a different service configuration for each service client in the runtime. By following this pattern, you can avoid the unintentionally "polluted" default service configuration bugs that can be very difficult to debug.

Answer 2

To use the custom configurations with each upload you can create temporary access key and secret with a session. Then you can use those keys to upload your file. Below is the code snippet
/// This function is used to authorize user with AWS.
private func connectWithAWS() -> AWSServiceConfiguration? {
/// Simple session credentials with keys and session token.
let credentialsProvider = AWSBasicSessionCredentialsProvider.init(accessKey: "TEMPORARY ACCESS KEY", secretKey: "TEMPORARY SECRET KEY", sessionToken: "TEMPORARY SESSION")
/// A service configuration object.
guard let configuration = AWSServiceConfiguration(region: .USEast1, credentialsProvider: credentialsProvider) else {
return nil
}
return configuration
}
func uploadFileToS3() {
/// Get configurations for bucket
guard let configuration = connectWithAWS() else {
///AWSServiceConfiguration Not Initialised.
return
}
///Check if a AWSS3TransferUtility already exist for current access key or not.
let trans = AWSS3TransferUtility.s3TransferUtility(forKey: "TEMPORARY ACCESS KEY")
if trans == nil {
/// If AWSS3TransferUtility is nil than create new for a access id
///
AWSS3TransferUtility.register(with: configuration, transferUtilityConfiguration: nil, forKey: "TEMPORARY ACCESS KEY") { (err) in
print("Error in AWSS3TransferUtility.register: ->>> \(err?.localizedDescription ?? "")")
}
}
///
/// Check if a AWSS3TransferUtility already exist for current access key or not.
guard let transferUtility = AWSS3TransferUtility.s3TransferUtility(forKey: "TEMPORARY ACCESS KEY") else {
return
}
///
/// Start Uploading process
///
let expression = AWSS3TransferUtilityUploadExpression()
expression.setValue("public-read", forRequestHeader: "x-amz-acl")
let s3BucketName = "BUCKET NAME"
let url = URL.init(fileURLWithPath: "fileURL")
transferUtility.uploadFile(url, bucket: s3BucketName, key: "fileName", contentType: "contentType", expression: expression) { (task, error) in
if error != nil {
print("Upload failed ❌ (\(error!))")
return
}
if task.status == AWSS3TransferUtilityTransferStatusType.completed {
let s3URL = "https://\(s3BucketName).s3.amazonaws.com/\(task.key)"
print("Uploaded to:\n\(s3URL)")
return
} else {
print("Not uploaded")
}
}.continueWith { (task) -> Any? in
if let error = task.error {
print("Upload failed ❌ (\(error))")
}
if task.result != nil, task.isCompleted == true {
let s3URL = "https://\(s3BucketName).s3.amazonaws.com/\(task.result!.key)"
print("Uploading Start of : \(s3URL)")
} else {
print("Unexpected empty result.")
}
return nil
}
}