Struggling with Ansible GCE inventory

I’m following the instructions at http://docs.ansible.com/ansible/guide_gce.html but failed to get gce.py running
`
./inventories/gce/gce.py --list

Traceback (most recent call last):
File “./inventories/gce/gce.py”, line 374, in
GceInventory()
File “./inventories/gce/gce.py”, line 115, in init
self.driver = self.get_gce_driver()
File “./inventories/gce/gce.py”, line 230, in get_gce_driver
gce = get_driver(Provider.GCE)(*args, **kwargs)
File “/usr/lib/python2.7/site-packages/libcloud/compute/drivers/gce.py”, line 1697, in init
super(GCENodeDriver, self).init(user_id, key, **kwargs)
File “/usr/lib/python2.7/site-packages/libcloud/common/base.py”, line 1190, in init
self.connection = self.connectionCls(*args, **conn_kwargs)
File “/usr/lib/python2.7/site-packages/libcloud/compute/drivers/gce.py”, line 98, in init
credential_file=credential_file, **kwargs)
File “/usr/lib/python2.7/site-packages/libcloud/common/google.py”, line 765, in init
user_id, key, auth_type, credential_file, scopes, **kwargs)
File “/usr/lib/python2.7/site-packages/libcloud/common/google.py”, line 651, in init
self.user_id, self.key, self.scopes, **kwargs)
File “/usr/lib/python2.7/site-packages/libcloud/common/google.py”, line 493, in init
“file: ‘%s’” % key)
ValueError: Missing (or not readable) key file: ‘’

`

I set the following env vars:

`

export GCE_EMAIL=my GCE client email
export GCE_PROJECT=my project
export GCE_CREDENTIALS_FILE_PATH=path to json file

`

the following works fine:

`
gcloud compute instances list

`
so the problem is not with my connectivity or permissions.

Any idea will be appreciated

Regards
Tzach

I’m using ansible 2.2.1.0