Return the client IP from the environment.

def get_client_ip(self):
        """Return the client IP from the environment."""

        if self.client_ip:
            return self.client_ip

        try:
            client = os.environ.get('SSH_CONNECTION',
                                    os.environ.get('SSH_CLIENT'))
            self.client_ip = client.split()[0]
            self.logdebug('client_ip: %s\n' % self.client_ip)
            return self.client_ip
        except:
            raise SSHEnvironmentError('cannot identify the ssh client '
                                      'IP address')