juju bootstrap failed with "discarding API open error"

#tail –f command.log
[DEBUG • 07-16 08:52:15] • cloudinstall.multi_install • (multi_install.py, do_install, 143)]
   Problem during bootstrap: '{'output': 'Bootstrapping environment "maas"
Starting new instance for initial state server
Launching instance
WARNING no architecture was specified, acquiring an arbitrary node
 - /MAAS/api/1.0/nodes/node-8620728c-2bb1-11e5-9498-0050568e7fe1/
Installing Juju agent on bootstrap instance
Waiting for address
Attempting to connect to perfumed-chain.maas:22
Attempting to connect to perfumed-chain.maas:22
Attempting to connect to 192.168.11.29:22
Logging to /var/log/cloud-init-output.log on remote host
Running apt-get update
Running apt-get upgrade
Installing package: curl
Installing package: cpu-checker
Installing package: bridge-utils
Installing package: rsyslog-gnutls
Installing package: cloud-utils
Installing package: cloud-image-utils
Installing package: tmux
Fetching tools: curl -sSfw \'tools from %{url_effective} downloaded: HTTP %{http_code}; time %{time_total}s; size %{size_download} bytes; speed %{speed_download} bytes/s \' --retry 10 -o $bin/tools.tar.gz <[https://streams.canonical.com/juju/tools/releases/juju-1.24.2-trusty-amd64.tgz]>
Bootstrapping Juju machine agent
Starting Juju machine agent (jujud-machine-0)
Bootstrap agent installed
WARNING discarding API open error: unable to connect to "wss://69.172.200.109:17070/environment/c0db9ace-778a-44e5-859c-3929ee7b7638/api"
ERROR unable to connect to "wss://perfumed-chain.maas:17070/environment/c0db9ace-778a-44e5-859c-3929ee7b7638/api"
', 'status': 1}'
[DEBUG • 07-16 08:52:15] • cloudinstall.utils • (utils.py, global_exchandler, 63)]
   Traceback (most recent call last):
  File "/usr/share/openstack/cloudinstall/utils.py", line 78, in run
    super().run()
  File "/usr/lib/python3.4/threading.py", line 868, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/share/openstack/cloudinstall/machinewait.py", line 127, in do_continue
    self.installer.do_install()
  File "/usr/share/openstack/cloudinstall/multi_install.py", line 144, in do_install
    raise Exception("Problem with juju bootstrap.")
Exception: Problem with juju bootstrap.

On MAAS node:
ubuntu@perfumed-chain:/var/log$ netstat -nat| grep 17070
tcp 0 0 127.0.0.1:33323 127.0.0.1:17070 ESTABLISHED
tcp 0 0 127.0.0.1:33350 127.0.0.1:17070 ESTABLISHED
tcp6 0 0 :::17070 :::* LISTEN
tcp6 0 0 127.0.0.1:17070 127.0.0.1:33323 ESTABLISHED
tcp6 0 0 127.0.0.1:17070 127.0.0.1:33350 ESTABLISHED