feat: Added support for specifying a custom endpoint for identity pools: issue 11275

[snagatsu]

Description of changes

you can specify a custom endpoint for accessing a Cognito user pool, such as signIn or signOut. However, you cannot specify a custom endpoint for accessing an identity pool, such as fetchAuthSession. We have added a custom endpoint for the identity pool to the amplifyconfig and implemented a solution.

Issue #, if available

#11275

Description of how you validated changes

You built a custom app using Amplify and verified that you can access the AWS API Gateway URL you provided. AWS API Gateway referenced this URL.
https://aws.amazon.com/jp/blogs/architecture/enriching-amazon-cognito-features-with-an-amazon-api-gateway-proxy/

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[nadetastic]

Hi @snagatsu thank you for your contribution! I'll review this with the team and follow up with any comments/updates.

[adadouche]

any updates on this PR?

[snagatsu]

there is no additional information available

[AllanZhengYP]

Hi @snagatsu, thanks a lot for the contribution. It helps a lot when we triage the feature requests. As of the implementation, the proposed one does not quite conform to our abstractions.

The main issue is that we need to resolve the Amplify configuration for endpoint in the provider layer like here and keep the awsClient layer as straightforward as possible:

amplify-js/packages/auth/src/providers/cognito/credentialsProvider/credentialsProvider.ts

Line 27 in f049a9e

export class CognitoAWSCredentialsAndIdentityIdProvider

For changes that modifies that public interfaces like this one, we need to go through internal processes to make sure their naming is reasonable and consistent. We also need to update our documentation too.

I will bring this to the team to discuss and keep you updated. The team might pick up the feature request.