Lightweight, unoptimized wrap of googleapiclient basic instance control

googleapiclient_instance_wrap.py

# A small script that wraps the basic functionality of the 
# (in my option somewhat confusing) googleapiclient features
# for instance control.

import time

from googleapiclient import discovery

cloud_config = dict(
  project='My-Project',
  zone='My-Zone'
)

class GCloudInstance:

	def __init__(self, name):
		self.name = name
		self.compute = discovery.build('compute', 'v1')

		self._fetch_data()
		
	def _fetch_data(self):
		self.instance_data = None
		all_instances = self.compute.instances().list(**cloud_config).execute()['items']
		for instance_data in all_instances:
			if instance_data['name'] == self.name:
				self.instance_data = instance_data
				break
		if not instance_data:
			raise ValueError('No instance %s'%name)

	@property
	def status_label(self):
		return self.instance_data['status']

	@property
	def is_available(self):
		return self.status_label == 'TERMINATED'

	@property
	def is_running(self):
		return self.status_label == 'RUNNING'

	@property
	def is_transitional(self):
		return not (self.is_available or self.is_running)

	@property
	def ip_address(self):
		access_conf = self.instance_data['accessConfigs'][0]
		if 'natIP' not in access_conf:
			return None
		return access_conf['natIP']

	def _instances_call(self, op_name):
		operation = getattr(self.compute.instances(), op_name)(**cloud_config, instance=self.name).execute()
		while True:
			status = self.compute.zoneOperations().get(**cloud_config, operation=operation['name']).execute()
			if status['status'] == 'DONE':
				break
			self._fetch_data()
			time.sleep(3)

	def start(self):
		self._instances_call('start')

	def stop(self):
		self._instances_call('stop')

# Example usage:
import sys
if __name__ == '__main__':
  my_instance = GCloudInstance('my-instance')
  if not my_instance.is_available:
    print('The instance is already running')
    sys.exit(1)
  my_instance.start()
  print('Instance available at %s'%my_instance.ip_address)
  my_instance.stop()