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 environement.

Setting up a devstack environemnt

# sudo apt-get install git -y || sudo yum install -y git
# git clone https://git.openstack.org/openstack-dev/devstack
# cd devstack && ./stack.sh

Starting the nova-serialproxy service

. code-block:: bash

# screen -S stack -X screen -t n-sproxy # screen -S stack -p n-sproxy -X stuff ‘sudo nova-serialproxyr’

Setting up a Nova environemnt

The entire configuration is provided in nova.conf through the category serial_console.

# cat >> /etc/nova/nova.conf <<EOF
[serial_console]
enabled = True
EOF

To get more information about available options see: - http://docs.openstack.org/trunk/config-reference/content/list-of-compute-config-options.html

You should now restart services ‘n-api’ and ‘n-cpu’ from the ‘stack’ screen; The command ./rejoin-stack.sh located to the root directory of devstack will let you to join screen. By the combination of the keys “Ctrl+a” you should be able to switch between services. Just kill them with “Ctrl+c” and restart them by using the command history provided by bash “Up-Arrow”.

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