def get_subnet_cidrs(cls, cidr=None, mask_bits=None, ip_version=None):
"""Iterate over a sequence of unused subnet CIDR for IP version
:param cidr: CIDR of the subnet to create
It can be either None, a str or a netaddr.IPNetwork instance
:param mask_bits: CIDR prefix length
It can be either None or a numeric value.
If cidr parameter is given then mask_bits is used to determinate a
sequence of valid CIDR to use as generated.
Please see netaddr.IPNetwork.subnet method documentation[1]
:param ip_version: ip version of generated subnet CIDRs
It can be None, IP_VERSION_4 or IP_VERSION_6
It has to match given CIDR if given
:return: iterator over reserved CIDRs of type netaddr.IPNetwork
[1] http://netaddr.readthedocs.io/en/latest/tutorial_01.html#supernets-and-subnets # noqa
"""
if cidr:
# Generate subnet CIDRs starting from given CIDR
# checking it is of requested IP version
cidr = netaddr.IPNetwork(cidr, version=ip_version)
else:
# Generate subnet CIDRs starting from configured values
ip_version = ip_version or cls._ip_version
if ip_version == const.IP_VERSION_4:
mask_bits = mask_bits or config.safe_get_config_value(
'network', 'project_network_mask_bits')
cidr = netaddr.IPNetwork(
config.safe_get_config_value('network',
'project_network_cidr'))
elif ip_version == const.IP_VERSION_6:
mask_bits = config.safe_get_config_value(
'network', 'project_network_v6_mask_bits')
cidr = netaddr.IPNetwork(
config.safe_get_config_value('network',
'project_network_v6_cidr'))
else:
raise ValueError('Invalid IP version: {!r}'.format(ip_version))
if mask_bits:
subnet_cidrs = cidr.subnet(mask_bits)
else:
subnet_cidrs = iter([cidr])
for subnet_cidr in subnet_cidrs:
if subnet_cidr not in cls.reserved_subnet_cidrs:
yield subnet_cidr
def resource_setup(cls):
super(RoutersTest, cls).resource_setup()
cls.tenant_cidr = (config.safe_get_config_value(
'network', 'project_network_cidr') if cls._ip_version == 4 else
config.safe_get_config_value(
'network', 'project_network_v6_cidr'))