"""
awslimitchecker/services/vpc.py
The latest version of this package is available at:
<https://github.com/jantman/awslimitchecker>
################################################################################
Copyright 2015-2017 Jason Antman <jason@jasonantman.com>
This file is part of awslimitchecker, also known as awslimitchecker.
awslimitchecker is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
awslimitchecker is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with awslimitchecker. If not, see <http://www.gnu.org/licenses/>.
The Copyright and Authors attributions contained herein may not be removed or
otherwise altered, except to add the Author attribution of a contributor to
this work. (Additional Terms pursuant to Section 7b of the AGPL v3)
################################################################################
While not legally required, I sincerely request that anyone who finds
bugs please submit them at <https://github.com/jantman/awslimitchecker> or
to me via email, and that you send any contributions or improvements
either as a pull request on GitHub, or to me via email.
################################################################################
AUTHORS:
Jason Antman <jason@jasonantman.com> <http://www.jasonantman.com>
################################################################################
"""
import abc # noqa
import logging
from collections import defaultdict
from .base import _AwsService
from ..limit import AwsLimit
from ..utils import paginate_dict
from botocore.exceptions import ClientError
logger = logging.getLogger(__name__)
[docs]class _VpcService(_AwsService):
service_name = 'VPC'
api_name = 'ec2'
[docs] def find_usage(self):
"""
Determine the current usage for each limit of this service,
and update corresponding Limit via
:py:meth:`~.AwsLimit._add_current_usage`.
"""
logger.debug("Checking usage for service %s", self.service_name)
self.connect()
for lim in self.limits.values():
lim._reset_usage()
self._find_usage_vpcs()
subnet_to_az = self._find_usage_subnets()
self._find_usage_ACLs()
self._find_usage_route_tables()
self._find_usage_gateways()
self._find_usage_nat_gateways(subnet_to_az)
self._have_usage = True
logger.debug("Done checking usage.")
[docs] def _find_usage_vpcs(self):
"""find usage for VPCs"""
# overall number of VPCs
vpcs = self.conn.describe_vpcs()
self.limits['VPCs']._add_current_usage(
len(vpcs['Vpcs']),
aws_type='AWS::EC2::VPC'
)
[docs] def _find_usage_subnets(self):
"""find usage for Subnets; return dict of SubnetId to AZ"""
# subnets per VPC
subnet_to_az = {}
subnets = defaultdict(int)
for subnet in self.conn.describe_subnets()['Subnets']:
subnets[subnet['VpcId']] += 1
subnet_to_az[subnet['SubnetId']] = subnet['AvailabilityZone']
for vpc_id in subnets:
self.limits['Subnets per VPC']._add_current_usage(
subnets[vpc_id],
aws_type='AWS::EC2::VPC',
resource_id=vpc_id
)
return subnet_to_az
[docs] def _find_usage_ACLs(self):
"""find usage for ACLs"""
# Network ACLs per VPC
acls = defaultdict(int)
for acl in self.conn.describe_network_acls()['NetworkAcls']:
acls[acl['VpcId']] += 1
# Rules per network ACL
self.limits['Rules per network ACL']._add_current_usage(
len(acl['Entries']),
aws_type='AWS::EC2::NetworkAcl',
resource_id=acl['NetworkAclId']
)
for vpc_id in acls:
self.limits['Network ACLs per VPC']._add_current_usage(
acls[vpc_id],
aws_type='AWS::EC2::VPC',
resource_id=vpc_id,
)
[docs] def _find_usage_route_tables(self):
"""find usage for route tables"""
# Route tables per VPC
tables = defaultdict(int)
for table in self.conn.describe_route_tables()['RouteTables']:
tables[table['VpcId']] += 1
# Entries per route table
self.limits['Entries per route table']._add_current_usage(
len(table['Routes']),
aws_type='AWS::EC2::RouteTable',
resource_id=table['RouteTableId']
)
for vpc_id in tables:
self.limits['Route tables per VPC']._add_current_usage(
tables[vpc_id],
aws_type='AWS::EC2::VPC',
resource_id=vpc_id,
)
[docs] def _find_usage_gateways(self):
"""find usage for Internet Gateways"""
# Internet gateways
gws = self.conn.describe_internet_gateways()
self.limits['Internet gateways']._add_current_usage(
len(gws['InternetGateways']),
aws_type='AWS::EC2::InternetGateway',
)
[docs] def _find_usage_nat_gateways(self, subnet_to_az):
"""
find usage for NAT Gateways
:param subnet_to_az: dict mapping subnet ID to AZ
:type subnet_to_az: dict
"""
# currently, some regions (sa-east-1 as one example) don't have NAT
# Gateway service; they return an AuthError,
# "This request has been administratively disabled."
try:
gws_per_az = defaultdict(int)
for gw in paginate_dict(self.conn.describe_nat_gateways,
alc_marker_path=['NextToken'],
alc_data_path=['NatGateways'],
alc_marker_param='NextToken'
)['NatGateways']:
if gw['SubnetId'] not in subnet_to_az:
logger.error('ERROR: NAT Gateway %s in SubnetId %s, but '
'SubnetId not found in subnet_to_az; Gateway '
'cannot be counted!', gw['NatGatewayId'],
gw['SubnetId'])
continue
gws_per_az[subnet_to_az[gw['SubnetId']]] += 1
for az in sorted(gws_per_az.keys()):
self.limits['NAT Gateways per AZ']._add_current_usage(
gws_per_az[az],
resource_id=az,
aws_type='AWS::EC2::NatGateway'
)
except ClientError:
logger.error('Caught exception when trying to list NAT Gateways; '
'perhaps NAT service does not exist in this region?',
exc_info=1)
[docs] def get_limits(self):
"""
Return all known limits for this service, as a dict of their names
to :py:class:`~.AwsLimit` objects.
:returns: dict of limit names to :py:class:`~.AwsLimit` objects
:rtype: dict
"""
if self.limits != {}:
return self.limits
limits = {}
limits['VPCs'] = AwsLimit(
'VPCs',
self,
5,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::VPC',
)
limits['Subnets per VPC'] = AwsLimit(
'Subnets per VPC',
self,
200,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::Subnet',
limit_subtype='AWS::EC2::VPC',
)
limits['Network ACLs per VPC'] = AwsLimit(
'Network ACLs per VPC',
self,
200,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::NetworkAcl',
limit_subtype='AWS::EC2::VPC',
)
limits['Rules per network ACL'] = AwsLimit(
'Rules per network ACL',
self,
20,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::NetworkAclEntry',
limit_subtype='AWS::EC2::NetworkAcl',
)
limits['Route tables per VPC'] = AwsLimit(
'Route tables per VPC',
self,
200,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::RouteTable',
limit_subtype='AWS::EC2::VPC',
)
limits['Entries per route table'] = AwsLimit(
'Entries per route table',
self,
50,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::Route',
limit_subtype='AWS::EC2::RouteTable',
)
limits['Internet gateways'] = AwsLimit(
'Internet gateways',
self,
5,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::InternetGateway',
)
limits['NAT Gateways per AZ'] = AwsLimit(
'NAT Gateways per AZ',
self,
5,
self.warning_threshold,
self.critical_threshold,
limit_type='AWS::EC2::NatGateway',
)
self.limits = limits
return limits
[docs] def required_iam_permissions(self):
"""
Return a list of IAM Actions required for this Service to function
properly. All Actions will be shown with an Effect of "Allow"
and a Resource of "*".
:returns: list of IAM Action strings
:rtype: list
"""
return [
'ec2:DescribeNatGateways',
'ec2:DescribeNetworkAcls',
'ec2:DescribeRouteTables',
'ec2:DescribeSubnets',
'ec2:DescribeVpcs',
]