#!/usr/bin/python3
#
# Copyright (c) 2018 Virtuozzo International GmbH. All rights reserved.
#
# This python script provides interface to configure network settings
# using netplan.
import argparse
import yaml
import os
import re
import subprocess
import sys
NETPLAN_CFG_DIR = "/etc/netplan/"
NETPLAN_CFG_PREFIX = "90-vz-"
def getArgParser():
"""
Init argparse
- "device" is mandatory for all commands.
- "ip" is used for gateway \ route related operations
"""
parser = argparse.ArgumentParser("Netplan configuration editor")
parser.add_argument('-a', '--action', action="store",
choices=("get_dhcp", "restart", "set_dhcp", "set_gateway", "set_ip", "set_route"))
parser.add_argument('-i', '--ip', action="store")
parser.add_argument('-d', '--device', action="store", required=True)
parser.add_argument('-p', '--proto', action="store")
parser.add_argument('-o', '--options', action="store", default="")
return parser
def is_ip_proto(addr, proto):
res = None
if int(proto) == 4:
res = "." in list(addr)
elif int(proto) == 6:
res = ":" in list(addr)
if res:
return True
return False
def split_route(route):
"""
Split route string into elemenets
"X.X.X.X/Z=X.X.X.Ym100" -> "X.X.X.X/Z X.X.X.Y 100"
Return tuple (to, via, metric)
"""
via = "0.0.0.0"
metric = ""
res = re.split("m", route.strip())
if res.__len__() == 2:
metric = int(res[1])
res = re.split("=", res[0])
if res.__len__() == 2:
via = res[1]
to = res[0]
return to, via, metric
def netmask_to_cidr(netmask):
"""
Convert netmask to CIDR notation. Netplan does not accept netmasks
"""
return sum([bin(int(x)).count('1') for x in netmask.split('.')])
class npConfig(object):
def __init__(self, **kwargs):
self._ifname = kwargs["device"]
self._action = kwargs["action"]
self._ip = kwargs["ip"]
self._proto = kwargs["proto"]
self._options = kwargs["options"]
config = {}
self.filename = NETPLAN_CFG_DIR + NETPLAN_CFG_PREFIX + self._ifname + ".yaml"
self.__load()
def __generate_skeleton_config(self):
"""
Generate skeleton config
"""
self.config = {'network': {"version": 2, 'ethernets': {self._ifname: {}}}}
def __get_route_tree(self):
"""
Retrieve pointer to the route subtree
"""
# Create empty list if it is missing to avoid KeyValue exceptions
if "routes" not in self.config["network"]["ethernets"][self._ifname]:
self.config["network"]["ethernets"][self._ifname]["routes"] = []
# Return subtree pointer to shorten and simplify further code
return self.config["network"]["ethernets"][self._ifname]["routes"]
def __set_gateway(self):
"""
set_gateway action implementation for netplan config
"""
ifcfg = self.config["network"]["ethernets"][self._ifname]
# to comply with scripts, we should only remove routes if there is
# at least single valid gateway to configure besides "remove*"
for ip in self._ip.split():
if 'remove' not in ip:
if "routes" in ifcfg:
ifcfg.pop("routes")
for ip in self._ip.split():
if 'remove' in ip:
continue
route_tree = self.__get_route_tree()
if self.__checkFeature("default-routes"):
route = {"via": ip, "on-link": "true", "to": "default"}
if route not in route_tree:
route_tree.append(route)
else:
gw_proto = "gateway4"
if is_ip_proto(ip, 6):
gw_proto = "gateway6"
ifcfg[gw_proto] = ip
# Configure on-link route to host-routed gateway
if ip == "169.254.0.1":
route = {"to": "169.254.0.1", "via": "0.0.0.0", "scope": "link"}
if route not in route_tree:
route_tree.append(route)
def __set_dhcp(self):
"""
set_dhcp action implementation for netplan config
TODO: its necessary to decide what to do with this function.
Original shell script removes configuration entirely and rewrites it
when dhcp is set. While it should be reasonable just to remove relevant
protocol (ipv4/ipv6) configuration and set dhcp.
For the sake of compatibility, function replicates existing behavior,
wipes configuration file and just sets dhcp.
"""
self.__generate_skeleton_config()
ifcfg = self.config["network"]["ethernets"][self._ifname]
for proto in list(self._proto):
if proto == '4':
ifcfg["dhcp4"] = "yes"
if proto == '6':
ifcfg["dhcp6"] = "yes"
def __set_route(self):
"""
set_route action implementation for netplan config
"""
route_tree = self.__get_route_tree()
for ip in self._ip.split():
if ip == 'remove':
for route in route_tree:
if is_ip_proto(route["to"], 4):
route_tree.remove(route)
elif ip == 'remove6':
for route in route_tree:
if is_ip_proto(route["to"], 6):
route_tree.remove(route)
else:
to, via, metric = split_route(ip)
route = {"to": to, "via": via}
if metric:
route["metric"] = metric
if to == "169.254.0.1":
route["scope"] = "link"
# Check for duplicates before adding route
if route not in route_tree:
route_tree.append(route)
def __set_ip(self):
"""
set_ip action implementation for netplan config
IMPORTANT: on each use old config is flushed. That is to ensure
backward-compatibility. prl_nettool supplies full list of IPs on each
set_ip invocation
"""
self.__generate_skeleton_config()
ifcfg = self.config["network"]["ethernets"][self._ifname]
for ip in self._ip.split():
if self._ip == 'remove' or self._ip == 'remove6':
continue
if "addresses" not in ifcfg:
ifcfg["addresses"] = []
# This is necessary for compatibility, we must replicate old behavior
if "/" not in list(ip):
if is_ip_proto(ip, 4):
ip += "/32"
else:
ip += "/64"
else:
if is_ip_proto(ip, 4):
addr, netmask = ip.split("/")
if "." in netmask:
netmask = netmask_to_cidr(netmask)
ip = addr + "/" + str(netmask)
ifcfg["addresses"].append(ip)
ifcfg["dhcp4"] = False
ifcfg["dhcp6"] = False
for opt in self._options.split():
if opt =="dhcp":
ifcfg["dhcp4"] = True
if opt =="dhcp6":
fcfg["dhcp6"] = True
def __checkFeature(self, feature):
"""
check if current version of netplan supports default-routes feature
"""
p = subprocess.Popen("netplan info".split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out = p.communicate()
if p.returncode:
print("netplan info failed [%d].\nstdout:%s\nstderr:%s\n" %
(p.returncode, str(out[0]), str(out[1])))
return False
if feature in str(out[0]):
return True
return False
def __restart(self):
"""
restart action implementation for netplan config
"""
p = subprocess.Popen("netplan apply".split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out = p.communicate()
if p.returncode:
print("netplan apply failed [%d].\nstdout:%s\nstderr:%s\n" %
(p.returncode, str(out[0]), str(out[1])))
return p.returncode
def __generate(self):
"""
restart action implementation for netplan config
"""
p = subprocess.Popen("netplan generate".split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out = p.communicate()
if p.returncode:
print("netplan generate failed [%d].\nstdout:%s\nstderr:%s\n" %
(p.returncode, str(out[0]), str(out[1])))
return p.returncode
def __get_dhcp(self):
"""
get_dhcp action implementation for netplan config
"""
ifcfg = self.config["network"]["ethernets"][self._ifname]
if self._proto == 6:
dhcpvp = "dhcp6"
else:
dhcpvp = "dhcp4"
if dhcpvp in ifcfg:
if ifcfg[dhcpvp]:
return 0
else:
return 1
else:
return 2
def __load(self):
"""
Read configuration file from disk. If it is missing - construct skeleton config
"""
if os.path.exists(self.filename):
with open(self.filename) as f:
self.config = yaml.load(f.read(), Loader=yaml.SafeLoader)
else:
self.__generate_skeleton_config()
def __save(self):
"""
Write config to the disk
"""
with open(self.filename + ".tmp", "w") as f:
f.write(yaml.dump(self.config, default_flow_style=False))
if os.path.exists(self.filename):
os.rename(self.filename, self.filename + ".bkp")
os.rename (self.filename + ".tmp", self.filename)
def perform_action(self):
"""
Perform action over the config file
"""
if self._action == "get_dhcp":
return self.__get_dhcp()
if self._action == "restart":
return self.__restart()
if self._action == "set_dhcp":
self.__set_dhcp()
elif self._action == "set_route":
self.__set_route()
elif self._action == "set_ip":
self.__set_ip()
elif self._action == "set_gateway":
self.__set_gateway()
self.__save()
self.__generate()
return 0
"""
Main body starts here
"""
if __name__ == '__main__':
args = getArgParser().parse_args()
npcfg = npConfig(action=args.action, device=args.device,
ip=args.ip, proto=args.proto, options=args.options)
res = npcfg.perform_action()
sys.exit(res)