How to get current cognito user from within go lambda - amazon-web-services

Question

I'm having a hard time to get the current Cognito user attributes from within my lambda function, that is written in Go. I'm currently doing:
userAttributes = request.RequestContext.Authorizer["claims"]
And if I want to get the email:
userEmail = request.RequestContext.Authorizer["claims"].(map[string]interface{})["email"].(string)
I don't think this is a good way or even an acceptable way - it must have a better way to do it.

Answer 1

You can use 3rd party library to convert map[string]interface{} to a concrete type. Check the mitchellh/mapstructure library, it will help you to implement in a better way.
So, you could improve your code with this code :
import "github.com/mitchellh/mapstructure"
type Claims struct {
Email string
// other fields
ID int
}
func claims(r request.Request) (Claims, error) {
input := r.RequestContext.Authorizer["claims"]
output := Claims{}
err := mapstructure.Decode(input, &output)
if err != nil {
return nil, err
}
return output, nil
}
And somewhere in your handlers, you could get your claims by calling this method
func someWhere(){
userClaims, err := claims(request)
if err != nil {
// handle
}
// you can now use : userClaims.Email, userClaims.ID
}
Don't forget to change func claims request parameter type according to yours (r parameter).