Ability to debug requests

[nikhilo]

I'm running the proxy on my mac, with an SSH tunnel through a VPC bastion host pointing to the ES domain inside of a VPC.
Run command,
docker run -it --rm -p 8080:8080 --add-host my-vpc-es.us-east-1.es.amazonaws.com:192.168.65.2 -e AWS_ACCESS_KEY_ID=(aws --profile=default configure get aws_access_key_id) -e AWS_SECRET_ACCESS_KEY=(aws --profile=default configure get aws_secret_access_key) -e AWS_REGION=us-east-1 --name aws-signing-proxy cllunsford/aws-signing-proxy -target https://my-vpc-es.us-east-1.es.amazonaws.com:9443 -region us-east-1

Getting following response with a 403
{"message":"The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details."}

Is there any way to debug the request/response? print headers maybe?