main.py

# Copyright 2015 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Google Compute Engine demo using the Google Python Client Library.
"""

__author__ = 'jonwayne@google.com (Jon Wayne Parrott)'

import sys
import time

from oauth2client.client import GoogleCredentials
from googleapiclient.discovery import build
from six.moves import input

# [START list_instances]
def list_instances(compute, project, zone):
    result = compute.instances().list(project=project, zone=zone).execute()
    return result['items']
# [END list_instances]


# [START create_instance]
def create_instance(compute, project, zone, name):
    source_disk_image = \
        "projects/debian-cloud/global/images/debian-7-wheezy-v20150320"
    machine_type = "zones/%s/machineTypes/n1-standard-1" % zone
    startup_script = open('startup-script.sh', 'r').read()
    image_url = "http://storage.googleapis.com/gce-demo-input/photo.jpg"
    image_caption = "Ready for dessert?"

    config = {
        'name': name,
        'machineType': machine_type,

        # Specify the boot disk and the image to use as a source.
        'disks': [
            {
                'boot': True,
                'autoDelete': True,
                'initializeParams': {
                    'sourceImage': source_disk_image,
                }
            }
        ],

        # Specify a network interface with NAT to access the public
        # internet.
        'networkInterfaces': [{
            'network': 'global/networks/default',
            'accessConfigs': [
                {'type': 'ONE_TO_ONE_NAT', 'name': 'External NAT'}
            ]
        }],

        # Allow the instance to access cloud storage and logging.
        'serviceAccounts': [{
            'email': 'default',
            'scopes': [
                'https://www.googleapis.com/auth/devstorage.read_write',
                'https://www.googleapis.com/auth/logging.write'
            ]
        }],

        # Metadata is readable from the instance and allows you to
        # pass configuration from deployment scripts to instances.
        'metadata': {
            'items': [{
                # Startup script is automatically executed by the
                # instance upon startup.
                'key': 'startup-script',
                'value': startup_script
            }, {
                'key': 'url',
                'value': image_url
            }, {
                'key': 'text',
                'value': image_caption
            }, {
                # Every project has a default Cloud Storage bucket that's
                # the same name as the project.
                'key': 'bucket',
                'value': project
            }]
        }
    }

    return compute.instances().insert(
        project=project,
        zone=zone,
        body=config).execute()
# [END create_instance]


# [START delete_instance]
def delete_instance(compute, project, zone, name):
    return compute.instances().delete(
        project=project,
        zone=zone,
        instance=name).execute()
# [END delete_instance]


# [START wait_for_operation]
def wait_for_operation(compute, project, zone, operation):
    sys.stdout.write('Waiting for operation to finish')
    while True:
        result = compute.zoneOperations().get(
            project=project,
            zone=zone,
            operation=operation).execute()

        if result['status'] == 'DONE':
            print("done.")
            if 'error' in result:
                raise Exception(result['error'])
            return result
        else:
            sys.stdout.write('.')
            sys.stdout.flush()
            time.sleep(1)
# [END wait_for_operation]


# [START run]
def run(project, zone, instance_name):
    credentials = GoogleCredentials.get_application_default()
    compute = build('compute', 'v1', credentials=credentials)

    print('Creating instance.')

    operation = create_instance(compute, project, zone, instance_name)
    wait_for_operation(compute, project, zone, operation['name'])

    instances = list_instances(compute, project, zone)

    print('Instances in project %s and zone %s:' % (project, zone))
    for instance in instances:
        print(' - ' + instance['name'])

    print("""
Instance created.
It will take a minute or two for the instance to complete work.
Check this URL: http://storage.googleapis.com/%s/output.png
Once the image is uploaded press enter to delete the instance.
""" % project)

    input()

    print('Deleting instance.')

    operation = delete_instance(compute, project, zone, instance_name)
    wait_for_operation(compute, project, zone, operation['name'])
# [END run]


def main():
    project = input('What is your project ID? ')
    zone = input(
        'What zone would you like to use? [us-central1-f] ') or 'us-central1-f'
    instance_name = 'demo-instance'
    run(project, zone, instance_name)


if __name__ == '__main__':
    main()