Tried connecting to the rds instance through the ec2 instance from and my local machine coming up with an error saying "Permission denied (public key)"
ssh -L 3306:db_instance_name.cxtitvmupc3w.us-west-2.rds.amazonaws.com:3306 my_instance_ip
Permission denied(public key)
This is ssh
saying that you have not provided a private key to establish the ssh session.
You would normally include -i keyfile.pem
in the command, exactly the same way you would normally ssh to the instance.