Nova flavor slots

nova-flavor-slots.py

#!/usr/bin/env python

import argparse
import os
import prettytable

from novaclient.v1_1 import client as novaclient

OS_USERNAME = os.environ['OS_USERNAME']
OS_PASSWORD = os.environ['OS_PASSWORD']
OS_AUTH_URL = os.environ['OS_AUTH_URL']
OS_TENANT_NAME = os.environ['OS_TENANT_NAME']
OS_REGION_NAME = os.environ['OS_REGION_NAME']


def nova():
    return novaclient.Client(
        username=OS_USERNAME,
        api_key=OS_PASSWORD,
        project_id=OS_TENANT_NAME,
        auth_url=OS_AUTH_URL,
        region_name=OS_REGION_NAME)

if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument('--flavor', required=True, help='Flavor.')
    args = parser.parse_args()

    nova = nova()
    flavor = nova.flavors.find(name=args.flavor)
    hypervisors = nova.hypervisors.list()

    hypervisor_stats = []
    for hypervisor in hypervisors:
        vcpus_available = hypervisor.vcpus - hypervisor.vcpus_used
        ram_available = (hypervisor.memory_mb - hypervisor.memory_mb_used)
        free_slots = min(vcpus_available / flavor.vcpus,
                         ram_available / flavor.ram)
        hypervisor_stats.append([
            hypervisor.service.get('host'),
            vcpus_available,
            ram_available / 1024,
            free_slots,
        ])

    fields = ['Hypervisor', 'Free VCPUs', 'Free RAM', 'Free Slots']
    pt = prettytable.PrettyTable([f for f in fields], caching=False)
    [pt.add_row(s) for s in hypervisor_stats]
    print pt