def _ipam_get_subnets(self, context, network_id, host):
Subnet = models_v2.Subnet
SegmentHostMapping = segment_svc_db.SegmentHostMapping
query = self._get_collection_query(context, Subnet)
query = query.filter(Subnet.network_id == network_id)
if not validators.is_attr_set(host):
query = query.filter(Subnet.segment_id.is_(None))
return [self._make_subnet_dict(c, context=context) for c in query]
# A host has been provided. Consider these two scenarios
# 1. Not a routed network: subnets are not on segments
# 2. Is a routed network: only subnets on segments mapped to host
# The following join query returns results for either. The two are
# guaranteed to be mutually exclusive when subnets are created.
query = query.add_entity(SegmentHostMapping)
query = query.outerjoin(
SegmentHostMapping,
and_(Subnet.segment_id == SegmentHostMapping.segment_id,
SegmentHostMapping.host == host))
# Essentially "segment_id IS NULL XNOR host IS NULL"
query = query.filter(
or_(
and_(Subnet.segment_id.isnot(None),
SegmentHostMapping.host.isnot(None)),
and_(Subnet.segment_id.is_(None),
SegmentHostMapping.host.is_(None))))
results = query.all()
# See if results are empty because the host isn't mapped to a segment
if not results:
# Check if it's a routed network (i.e subnets on segments)
query = self._get_collection_query(context, Subnet)
query = query.filter(Subnet.network_id == network_id)
query = query.filter(Subnet.segment_id.isnot(None))
if query.count() == 0:
return []
# It is a routed network but no subnets found for host
raise segment_exc.HostNotConnectedToAnySegment(
host=host, network_id=network_id)
# For now, we're using a simplifying assumption that a host will only
# touch one segment in a given routed network. Raise exception
# otherwise. This restriction may be relaxed as use cases for multiple
# mappings are understood.
segment_ids = {
subnet.segment_id
for subnet, mapping in results if mapping
}
if 1 < len(segment_ids):
raise segment_exc.HostConnectedToMultipleSegments(
host=host, network_id=network_id)
return [
self._make_subnet_dict(subnet, context=context)
for subnet, _mapping in results
]
def _ipam_get_subnets(self,
context,
network_id,
host,
service_type=None,
fixed_configured=False):
"""Return eligible subnets
If no eligible subnets are found, determine why and potentially raise
an appropriate error.
"""
subnets = self._find_candidate_subnets(context, network_id, host,
service_type, fixed_configured)
if subnets:
subnet_dicts = [
self._make_subnet_dict(subnet, context=context)
for subnet in subnets
]
# Give priority to subnets with service_types
return sorted(subnet_dicts,
key=lambda subnet: not subnet.get('service_types'))
# Determine why we found no subnets to raise the right error
query = self._query_subnets_on_network(context, network_id)
if self.is_host_set(host):
# Empty because host isn't mapped to a segment with a subnet?
s_query = query.filter(models_v2.Subnet.segment_id.isnot(None))
if s_query.limit(1).count() != 0:
# It is a routed network but no subnets found for host
raise segment_exc.HostNotConnectedToAnySegment(
host=host, network_id=network_id)
if not query.limit(1).count():
# Network has *no* subnets of any kind. This isn't an error.
return []
# Does filtering ineligible service subnets makes the list empty?
query = self._query_filter_service_subnets(query, service_type)
if query.limit(1).count():
# No, must be a deferred IP port because there are matching
# subnets. Happens on routed networks when host isn't known.
raise ipam_exceptions.DeferIpam()
raise ipam_exceptions.IpAddressGenerationFailureNoMatchingSubnet(
network_id=network_id, service_type=service_type)
def network_has_no_subnet(cls, context, network_id, host, service_type):
# Determine why we found no subnets to raise the right error
query = cls.query_subnets_on_network(context, network_id)
if cls.is_host_set(host):
# Empty because host isn't mapped to a segment with a subnet?
s_query = query.filter(cls.db_model.segment_id.isnot(None))
if s_query.limit(1).count() != 0:
# It is a routed network but no subnets found for host
raise segment_exc.HostNotConnectedToAnySegment(
host=host, network_id=network_id)
if not query.limit(1).count():
# Network has *no* subnets of any kind. This isn't an error.
return True
# Does filtering ineligible service subnets makes the list empty?
query = SubnetServiceType.query_filter_service_subnets(
query, service_type)
if query.limit(1).count():
# No, must be a deferred IP port because there are matching
# subnets. Happens on routed networks when host isn't known.
raise ipam_exceptions.DeferIpam()
return False
