Spawn a process using clouds.yaml to populate OS_* environment variables

cloud.py

#!/usr/bin/env python3

# Spawn a process using clouds.yaml to populate OS_* environment variables
# Or use it to set environment variables in the current shell:
#   $ eval $(cloud <cloud> --export)

import argparse
import os
import sys
import openstack

parser = argparse.ArgumentParser()
parser.add_argument('cloud', help='clouds.yaml entry')
parser.add_argument('--export', '-e',
                    help='show export shell commands and exit (show password)',
                    action='store_true',
                    default=False,)
parser.add_argument('--verbose', '-v', help='show OS_* values (hide password)',
                    action='store_true',
                    default=False,)
parser.add_argument('command', help='command to execute',
                    nargs=argparse.REMAINDER)
args = parser.parse_args()

conn = openstack.connect(cloud=args.cloud)
config = conn.config.config
auth = config['auth']

# OS_CLOUD_NAME can be used in the child process
environ = {
    'OS_CLOUD_CONFIG_NAME': args.cloud,
    'OS_CACERT': config.get('cacert'),
    'OS_VOLUME_API_VERSION': config.get('volume_api_version'),
    'OS_VERIFY': str(config.get('verify')),
    'OS_FOOBAR': config.get('foobar'),
    'OS_REGION_NAME': config.get('region_name'),
    'OS_IDENTITY_API_VERSION': config.get('identity_api_version'),
    'OS_IDENTITY_ENDPOINT_OVERRIDE': config.get('identity_endpoint_override'),
    'OS_AUTH_URL': auth.get('auth_url'),
    'OS_USER_DOMAIN_NAME': auth.get('user_domain_name'),
    'OS_USERNAME': auth.get('username'),
    'OS_PASSWORD': auth.get('password'),
    'OS_PROJECT_DOMAIN_NAME': auth.get('project_domain_name'),
    'OS_PROJECT_NAME': auth.get('project_name'),
    'OS_TENANT_NAME': auth.get('project_name'),
    }

environ = {k: v for k, v in environ.items() if v is not None}
if args.verbose:
    for k in environ.keys():
        if k == 'OS_PASSWORD':
            print("{}: ********".format(k))
        else:
            print("{}: {}".format(k, str(environ[k])))
if args.export:
    for k in environ.keys():
        print("export {}={}".format(k, str(environ[k])))
    sys.exit(0)

os.environ.update(environ)
command = "bash" if len(args.command) == 0 else " ".join(args.command)
os.system(command)