octavia/octavia/amphorae/backends/utils/nftable_utils.py

64 lines
2.8 KiB
Python

# Copyright 2024 Red Hat, Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import os
import stat
from octavia.common import constants as consts
def write_nftable_vip_rules_file(interface_name, rules):
flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
# mode 00600
mode = stat.S_IRUSR | stat.S_IWUSR
# Create some strings shared on both code paths
table_string = f'table {consts.NFT_FAMILY} {consts.NFT_VIP_TABLE} {{\n'
chain_string = f' chain {consts.NFT_VIP_CHAIN} {{\n'
hook_string = (f' type filter hook ingress device {interface_name} '
f'priority {consts.NFT_SRIOV_PRIORITY}; policy drop;\n')
# Check if an existing rules file exists or we if need to create an
# "drop all" file with no rules except for VRRP. If it exists, we should
# not overwrite it here as it could be a reboot unless we were passed new
# rules.
if os.path.isfile(consts.NFT_VIP_RULES_FILE):
if not rules:
return
with os.fdopen(
os.open(consts.NFT_VIP_RULES_FILE, flags, mode), 'w') as file:
# Clear the existing rules in the kernel
# Note: The "nft -f" method is atomic, so clearing the rules will
# not leave the amphora exposed.
file.write(f'flush chain {consts.NFT_FAMILY} '
f'{consts.NFT_VIP_TABLE} {consts.NFT_VIP_CHAIN}\n')
file.write(table_string)
file.write(chain_string)
file.write(hook_string)
# TODO(johnsom) Add peer ports here consts.HAPROXY_BASE_PEER_PORT
# and ip protocol 112 for VRRP. Need the peer address
for rule in rules:
file.write(f' {rule}\n')
file.write(' }\n') # close the chain
file.write('}\n') # close the table
else: # No existing rules, create the "drop all" base rules
with os.fdopen(
os.open(consts.NFT_VIP_RULES_FILE, flags, mode), 'w') as file:
file.write(table_string)
file.write(chain_string)
file.write(hook_string)
# TODO(johnsom) Add peer ports here consts.HAPROXY_BASE_PEER_PORT
# and ip protocol 112 for VRRP. Need the peer address
file.write(' }\n') # close the chain
file.write('}\n') # close the table