issue #150: quick script to run ansible against gcloud instance group

examples/playbook/gcloud-ansible-playbook.py

+#!/usr/bin/env python
+
+import os
+import sys
+
+import googleapiclient.discovery
+
+
+def main():
+    project = 'mitogen-load-testing'
+    zone = 'asia-south1-c'
+    group_name = 'micro-debian9'
+
+    client = googleapiclient.discovery.build('compute', 'v1')
+    resp = client.instances().list(project=project, zone=zone).execute()
+
+    ips = []
+    for inst in resp['items']:
+        if inst['status'] == 'RUNNING' and inst['name'].startswith(group_name):
+            ips.extend(
+                bytes(config['natIP'])
+                for interface in inst['networkInterfaces']
+                for config in interface['accessConfigs']
+            )
+
+    print 'Addresses:', ips
+    os.execvp('ansible-playbook', [
+        'anisble-playbook',
+        '--user=dw',
+        '--inventory-file=' + ','.join(ips) + ','
+    ] + sys.argv[1:])
+
+
+if __name__ == '__main__':
+    main()