Serializes to JSON.

def export(self):
        """Serializes to JSON."""
        fields = ['id', 'host', 'port', 'user']
        out = {}
        for field in fields:
            out[field] = getattr(self, field, None)
        out['mountOptions'] = self.mount_opts
        out['mountPoint'] = self.mount_point
        out['beforeMount'] = self.cmd_before_mount
        out['authType'] = self.auth_method
        out['sshKey'] = self.ssh_key
        return json.dumps(out, indent=4)