nova/doc/source/contributor/testing/serial-console.rst

Testing Serial Console

The main aim of this feature is exposing an interactive web-based serial consoles through a web-socket proxy. This page describes how to test it from a devstack environment.

Setting up a devstack environment

For instructions on how to setup devstack with serial console support enabled see this guide.

Testing the API

Starting a new instance.

# cd devstack && . openrc
# nova boot --flavor 1 --image cirros-0.3.2-x86_64-uec cirros1

Nova provides a command nova get-serial-console which will returns a URL with a valid token to connect to the serial console of VMs.

# nova get-serial-console cirros1
+--------+-----------------------------------------------------------------+
| Type   | Url                                                             |
+--------+-----------------------------------------------------------------+
| serial | ws://127.0.0.1:6083/?token=5f7854b7-bf3a-41eb-857a-43fc33f0b1ec |
+--------+-----------------------------------------------------------------+

Currently nova does not provide any client able to connect from an interactive console through a web-socket. A simple client for test purpose can be written with few lines of Python.

# sudo easy_install ws4py || sudo pip install ws4py
# cat >> client.py <<EOF
import sys
from ws4py.client.threadedclient import WebSocketClient
class LazyClient(WebSocketClient):
    def run(self):
        try:
            while not self.terminated:
                try:
                    b = self.sock.recv(4096)
                    sys.stdout.write(b)
                    sys.stdout.flush()
                except: # socket error expected
                    pass
        finally:
            self.terminate()
if __name__ == '__main__':
    if len(sys.argv) != 2 or not sys.argv[1].startswith("ws"):
        print "Usage %s: Please use websocket url"
        print "Example: ws://127.0.0.1:6083/?token=xxx"
        exit(1)
    try:
        ws = LazyClient(sys.argv[1], protocols=['binary'])
        ws.connect()
        while True:
            # keyboard event...
            c = sys.stdin.read(1)
            if c:
                ws.send(c)
        ws.run_forever()
    except KeyboardInterrupt:
        ws.close()
EOF

# python client.py ws://127.0.0.1:6083/?token=5f7854b7-bf3a-41eb-857a-43fc33f0b1ec
<enter>
cirros1 login