Return the key string for the SSH public key

def get_pubkey(self):
        '''
        Return the key string for the SSH public key
        '''
        if '__master_opts__' in self.opts and \
                self.opts['__master_opts__'].get('ssh_use_home_key') and \
                os.path.isfile(os.path.expanduser('~/.ssh/id_rsa')):
            priv = os.path.expanduser('~/.ssh/id_rsa')
        else:
            priv = self.opts.get(
                    'ssh_priv',
                    os.path.join(
                        self.opts['pki_dir'],
                        'ssh',
                        'salt-ssh.rsa'
                        )
                    )
        pub = '{0}.pub'.format(priv)
        with salt.utils.files.fopen(pub, 'r') as fp_:
            return '{0} rsa root@master'.format(fp_.read().split()[1])