Trying to set up Amplify with Cognito and CDK

While there isn't a specific guide for setting up Google Identity Providers with Amplify and Cognito using CDK, I can provide some guidance on how to approach this.

1. Setting up Google Identity Providers using CDK: You can use the CDK to create a Cognito User Pool and configure it with a Google Identity Provider. Here's a general approach:

• Create a Cognito User Pool using the aws-cdk-lib/aws-cognito module.
• Add a Google Identity Provider to the User Pool using the UserPoolIdentityProviderGoogle construct.
• Configure the User Pool Client to allow the Google provider.

2. Connecting preexisting backend to frontend with Amplify.configure: To connect your CDK-created backend to your frontend using Amplify, you'll need to pass the necessary configuration to Amplify.configure(). This includes:

• The User Pool ID
• The User Pool Client ID
• The Identity Pool ID (if you're using one)
• The OAuth configuration, including the domain, scope, and redirect sign-in/sign-out URLs

You can output these values from your CDK stack and use them in your frontend code.

3. Mapping users from different sign-in methods to the same account: Cognito supports linking social identities to a user pool account. When a user signs in with a social provider like Google, Cognito can either create a new user or link the social identity to an existing user based on the email address.

To enable this:

• Ensure that "email" is a required attribute in your User Pool.
• Configure your User Pool to allow users to sign up and sign in with their email address.
• Set up attribute mapping for the Google Identity Provider to map the email attribute.

This way, whether a user signs in with Google or with email and password, Cognito will use the email address to determine if it's an existing user or a new one.

Remember to handle cases where a user might try to sign up with an email that's already associated with a social identity, and vice versa. You may need to implement custom logic in your application to manage these scenarios.

For the signInWithRedirect function, ensure that you've correctly set up the OAuth flows in your Cognito User Pool Client and that your redirect URIs are properly configured both in the Cognito settings and in your Google Developer Console.

Sources
Use existing Cognito resources - React - AWS Amplify Gen 2 Documentation
Set up Amplify Auth - AWS Amplify Gen 2 Documentation