'Get the public key specified by :key_name:
:param key_name: the name of the key to look for
:returns: the keypair (name, public_key) for :key_name:
:raises: exception.EntityNotFound'

def get_keypair(self, key_name):

    try:
        return self.client().keypairs.get(key_name)
    except exceptions.NotFound:
        raise exception.EntityNotFound(entity='Key', name=key_name)
