# class RCASSHProxy:
#     def __init__(self, hosts, request):
#         auth_str = request.headers['Authorization'].split(' ')[1]
#         user, passw = base64.urlsafe_b64decode(
#             '{}==='.format(auth_str)).decode('utf8').split(':')
#         usernames = it.repeat(user)
#         passwords = it.repeat(passw)
#         self.jwt = request.headers['X-AUTH-TOKEN']
#         self.prefix = '/opt/maglev/bin'
#         self.clients = [(host, paramiko.SSHClient()) for host in hosts]
#         for (h, c), h, u, p in zip(self.clients, hosts, usernames, passwords):
#             c.set_missing_host_key_policy(paramiko.WarningPolicy)
#             c.connect(h, username=u, password=p)
#
#     def _exec_cmd(self, cmd, opts=None):
#         opts = opts or {}
#         abscmd='{} {}'.format(os.path.join(self.prefix, 'exec_proxy.py'), cmd)
#         res = [(h, c.exec_command(abscmd, environment=dict(CLUSTER=h, **opts)))
#                for (h, c) in self.clients]
#
#         def try_json(ress):
#             utf8reader = codecs.getreader('utf8')
#             for h, (_, res, err) in ress:
#                 errstr = utf8reader(err).read(-1)
#                 r = utf8reader(res).read(-1)
#                 try:
#                     yield h, json.loads(r), errstr
#                 except ValueError:
#                     yield h, r, errstr
#
#         return [
#             {
#                 'host': h,
#                 'err': e,
#                 'out': o
#             } for h, o, e in try_json(res)
#         ]
#
#     def _with_err(self, x):
#         if any(bool(i['err']) for i in x):
#             return x, RCAStatus.ERROR
#
#         status_set = {i['out']['status'] for i in x}
#         status = RCAStatus(status_set.pop()) if len(status_set) == 1 \
#             else RCAStatus.RUNNING
#         return x, status
#
#     def delete(self, _id):
#         return self._with_err(self._exec_cmd('delete {}'.format(_id)))
#
#     def status(self, _id):
#         return self._with_err(self._exec_cmd('status {}'.format(_id)))
#
#     def exec(self, cmd, _id, name, description):
#         opts = dict(RCA_DIR='/var/run/maglev/{}.tmp'.format(_id),
#                     STDOUT='/var/run/maglev/{}.stdout'.format(_id),
#                     OUTFILE='/var/run/maglev/{}.output.tar.gz'.format(_id),
#                     TOKEN=self.jwt)
#         return self._with_err(self._exec_cmd('exec {} /opt/maglev/bin/{}'
#                                              .format(_id, cmd), opts))
#
#     def download(self, _id):
#         out = namedtuple('download_struct', ['tempfiles', 'outbytes_err_t'])
#         sftps = [c.open_sftp() for h, c in self.clients]
#         temptuple = [tempfile.TemporaryFile() for _ in sftps]
#         outbytes = []
#         for source, fobj in zip(sftps, temptuple):
#             source.getfo('/var/run/maglev/{}.compiled.tar.gz'.format(_id), fobj)
#             outbytes.append((fobj.tell(), None))
#             fobj.seek(0)
#         return out(tempfiles=temptuple, outbytes_err_t=outbytes)