def find_device(self):
self.logger.info('Finding device.')
device_name = None
count = self.machine.increment_counter(self.state_name)
request = data.request_config(self.machine.request_id)
image_is_reusable = data.image_is_reusable(request['image'])
free_devices = data.get_free_devices(
environment=request['environment'],
device_name=request['requested_device'])
if free_devices:
if image_is_reusable:
devices_with_image = [x for x in free_devices
if x['image'] == request['image'] and
data.from_json(x['boot_config']) ==
data.from_json(request['boot_config'])]
if devices_with_image:
free_devices = devices_with_image
# pick a device at random from the returned list
device_name = random.choice(free_devices)['name']
self.logger.info('Assigning device %s.' % device_name)
if data.reserve_device(self.machine.request_id,
device_name):
self.logger.info('Request succeeded.')
self.machine.goto_state(contacting_lifeguard)
else:
self.logger.warn('Request failed!')
if request['requested_device'] == 'any':
if count >= self.MAX_ANY_REQUESTS:
self.logger.warn('Hit maximum number of attempts to find '
'a free device; giving up.')
self.machine.goto_state(device_not_found)
else:
if count >= self.MAX_SPECIFIC_REQUESTS:
self.logger.warn('Requested device %s is busy.' %
device_name)
self.machine.goto_state(device_busy)
def contact_lifeguard(self, request_config):
# If the requested image is reusable and we got a device with that
# image and the requested bootconfig, just power cycle it.
# Otherwise, image it. Note that there will be a failure if the
# image is not installed and the device is not imageable.
event = ''
device_request_data = {}
assigned_device_name = request_config['assigned_device']
if data.image_is_reusable(request_config['image']):
device_config = data.device_config(request_config['assigned_device'])
if (device_config['image'] == request_config['image'] and
data.from_json(device_config['boot_config']) ==
data.from_json(request_config['boot_config'])):
event = 'please_power_cycle'
if not event:
# Use the device's hardware type and requested image to find the
# pxe config, if any.
event = 'please_image'
device_request_data['boot_config'] = request_config['boot_config']
device_request_data['image'] = request_config['image']
device_url = 'http://%s/api/device/%s/event/%s/' % (
data.get_server_for_device(assigned_device_name),
assigned_device_name, event)
# FIXME: make this asynchronous so slow/missing servers don't halt
# the state machine.
try:
urllib.urlopen(device_url, json.dumps(device_request_data))
except IOError:
self.logger.warn('Could not contact lifeguard server at %s' %
device_url)
return False
return True