def read_ssh_pubkey(ssh_key: str) -> str:
    """
    Read the public key of the generated ssh-key and returns it in a format acceptable for
    instance Metadata.
    """
    with open(ssh_key + '.pub') as key_file:
        pub_key = key_file.read()
    user = pub_key.rsplit(' ', 1)[1].split('@')[0]
    return f"{user}:{pub_key}"