Using AWS Lambda with Cognito and API Gateway

问题

How to get user in Lambda function? User is authenticated in Cognito and invokes lambda with API Gateway. API Gateway method has AWS_IAM authorizer and checked "Use Lambda Proxy integration" checkbox

回答1:

If you have checked AWS_IAM API Gateway, identity of the end user available to your function. You can access the Identity ID as follows.

exports.handler = function(event, context) {
    var identity = event.requestContext.identity.cognitoIdentityId;
    console.log("clientID = " + identity);

    context.succeed("Your client ID is " + identity);
}

Then using the AWS SDK for Cognito invoking describeIdentity-property method, you should be able to retrieve additional information available for the identity.

var params = {
  IdentityId: 'STRING_VALUE' /* required */
};
cognitoidentity.describeIdentity(params, function(err, data) {
  if (err) console.log(err, err.stack); // an error occurred
  else     console.log(data);           // successful response
});

来源：https://stackoverflow.com/questions/46108431/using-aws-lambda-with-cognito-and-api-gateway