extra.py 文件源码

def pop_ip(env=None):
    """Picks an ip from env['provider_net'].

    It will first take ips in the extra_ips if possible.
    extra_ips is a list of isolated ips whereas ips described
    by the [provider_net.start, provider.end] range is a continuous
    list of ips.
    """
    # Construct the pool of ips
    extra_ips = env['provider_net'].get('extra_ips', [])
    if len(extra_ips) > 0:
        ip = extra_ips.pop()
        env['provider_net']['extra_ips'] = extra_ips
        return ip

    ips = list(IPRange(env['provider_net']['start'],
                       env['provider_net']['end']))

    # Get the next ip
    ip = str(ips.pop())

    # Remove this ip from the env
    env['provider_net']['end'] = str(ips.pop())

    return ip