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| #!/usr/bin/env python | |
| # Copyright 2015 Canonical Ltd. | |
| # Licensed under the AGPLv3, see LICENCE file for details. | |
| # | |
| # This file has been and should be formatted using pyfmt(1). | |
| # | |
| from __future__ import print_function | |
| import argparse | |
| import os | |
| import re | |
| import shutil | |
| import subprocess | |
| import sys | |
| import time | |
| class SeekableIterator(object): | |
| """An iterator that supports relative seeking.""" | |
| def __init__(self, iterable): | |
| self.iterable = iterable | |
| self.index = 0 | |
| def __iter__(self): | |
| return self | |
| def next(self): # Python 2 | |
| try: | |
| value = self.iterable[self.index] | |
| self.index += 1 | |
| return value | |
| except IndexError: | |
| raise StopIteration | |
| def __next__(self): # Python 3 | |
| return self.next() | |
| def seek(self, n, relative=False): | |
| if relative: | |
| self.index += n | |
| else: | |
| self.index = n | |
| if self.index < 0 or self.index >= len(self.iterable): | |
| raise IndexError | |
| class PhysicalInterface(object): | |
| """Represents a physical ('auto') interface.""" | |
| def __init__(self, definition): | |
| self.name = definition.split()[1] | |
| def __str__(self): | |
| return self.name | |
| class LogicalInterface(object): | |
| """Represents a logical ('iface') interface.""" | |
| def __init__(self, definition, options=None): | |
| if not options: | |
| options = [] | |
| _, self.name, self.family, self.method = definition.split() | |
| self.options = options | |
| self.is_bonded = [x for x in self.options if "bond-" in x] | |
| self.is_alias = ":" in self.name | |
| self.is_vlan = [x for x in self.options if x.startswith("vlan-raw-device")] | |
| self.is_active = self.method == "dhcp" or self.method == "static" | |
| self.is_bridged = [x for x in self.options if x.startswith("bridge_ports ")] | |
| def __str__(self): | |
| return self.name | |
| def bridge_now(self, prefix, bridge_name): | |
| # https://wiki.archlinux.org/index.php/Network_bridge | |
| # ip addr delete dev <interface name> <cidr> | |
| if bridge_name is None: | |
| bridge_name = prefix + self.name | |
| args = { | |
| 'bridge': bridge_name, | |
| 'parent': self.name, | |
| } | |
| addr = check_shell_cmd('ip -d addr show {parent}'.format(**args)) | |
| flags = re.search('<(.*?)>', addr).group(1).split(',') | |
| v4addrs = re.findall('\s+inet (\S+) ', addr) | |
| v6addrs = re.findall('\s+inet6 (\S+) ', addr) | |
| for exclude_flag in ['LOOPBACK', 'SLAVE']: | |
| if exclude_flag in flags: | |
| # Don't bridge the loopback interface or slaves of bonds. | |
| return | |
| # Save routes | |
| routes = check_shell_cmd('ip route show dev {parent}'.format(**args)) | |
| # Add the bridge | |
| print_shell_cmd('ip link add name {bridge} type bridge'.format(**args)) | |
| print_shell_cmd('ip link set {bridge} up'.format(**args)) | |
| print_shell_cmd('ip link set {parent} master {bridge}'.format(**args)) | |
| if self.method == "dhcp": | |
| self._move_dhclient_to_bridge(args) | |
| else: | |
| self._move_addresses_and_routes_to_bridge(args, v4addrs + v6addrs, routes) | |
| print('Done bridging {parent} with {bridge}'.format(**args)) | |
| def _move_addresses_and_routes_to_bridge(self, args, addresses, routes): | |
| # If we have a static address we should move it to the bridge. This | |
| # seems to be tradition more than logic (bridge being L2). It seems | |
| # that it is done because routes are generated by where an IP address | |
| # is assigned - i.e. eth4 has address 10.0.0.1/24 so everything on that | |
| # subnet should go out eth4. | |
| print_shell_cmd('ip addr flush dev {parent}'.format(**args)) | |
| for args['address'] in addresses: | |
| # Move address from parent to bridge | |
| print_shell_cmd('ip addr add dev {bridge} {address}'.format(**args)) | |
| for route in routes.splitlines(): | |
| # ip route replace will add missing routes or update existing | |
| # ones. Move routes from parent to bridge. | |
| if 'default' in route: | |
| print_shell_cmd('ip route replace {} dev {bridge}'.format(route, **args)) | |
| def _move_dhclient_to_bridge(self, args): | |
| # Look for /run/dhclient.{parent}.pid and, if found, the interface is | |
| # DHCP and we need to release dhclient against the parent and start it | |
| # against the bridge. | |
| if os.path.isfile('/run/dhclient.{parent}.pid'.format(**args)): | |
| # DHCP | |
| with open('/run/dhclient.{parent}.pid'.format(**args)) as f: | |
| pid = f.read().rstrip() | |
| with open('/proc/{}/cmdline'.format(pid)) as proc: | |
| # /proc/<pid>/cmdline separates args with 0, not a space. | |
| dh_args = proc.read().split(chr(0)) | |
| start = ' '.join(dh_args) | |
| start = re.sub(args['parent'], args['bridge'], start) | |
| start = re.sub(' -1 ', ' ', start) | |
| print('Restarting dhclient') | |
| dh_args[1:1] = ['-r'] | |
| print_shell_cmd(' '.join(dh_args)) | |
| print_shell_cmd(start) | |
| # Returns an ordered set of stanzas to bridge this interface | |
| def bridge(self, prefix, bridge_name, add_auto_stanza): | |
| if bridge_name is None: | |
| bridge_name = prefix + self.name | |
| # Note: the testing order here is significant. | |
| if not self.is_active or self.is_bridged: | |
| return self._bridge_unchanged(add_auto_stanza) | |
| elif self.is_alias: | |
| return self._bridge_alias(add_auto_stanza) | |
| elif self.is_vlan: | |
| return self._bridge_vlan(bridge_name, add_auto_stanza) | |
| elif self.is_bonded: | |
| return self._bridge_bond(bridge_name, add_auto_stanza) | |
| else: | |
| return self._bridge_device(bridge_name) | |
| def _bridge_device(self, bridge_name): | |
| s1 = IfaceStanza(self.name, self.family, "manual", []) | |
| s2 = AutoStanza(bridge_name) | |
| options = list(self.options) | |
| options.append("bridge_ports {}".format(self.name)) | |
| s3 = IfaceStanza(bridge_name, self.family, self.method, options) | |
| return [s1, s2, s3] | |
| def _bridge_vlan(self, bridge_name, add_auto_stanza): | |
| stanzas = [] | |
| s1 = IfaceStanza(self.name, self.family, "manual", self.options) | |
| stanzas.append(s1) | |
| if add_auto_stanza: | |
| stanzas.append(AutoStanza(bridge_name)) | |
| options = [x for x in self.options if not x.startswith("vlan")] | |
| options.append("bridge_ports {}".format(self.name)) | |
| s3 = IfaceStanza(bridge_name, self.family, self.method, options) | |
| stanzas.append(s3) | |
| return stanzas | |
| def _bridge_alias(self, add_auto_stanza): | |
| stanzas = [] | |
| if add_auto_stanza: | |
| stanzas.append(AutoStanza(self.name)) | |
| s1 = IfaceStanza(self.name, self.family, self.method, list(self.options)) | |
| stanzas.append(s1) | |
| return stanzas | |
| def _bridge_bond(self, bridge_name, add_auto_stanza): | |
| stanzas = [] | |
| if add_auto_stanza: | |
| stanzas.append(AutoStanza(self.name)) | |
| s1 = IfaceStanza(self.name, self.family, "manual", list(self.options)) | |
| s2 = AutoStanza(bridge_name) | |
| options = [x for x in self.options if not x.startswith("bond")] | |
| options.append("bridge_ports {}".format(self.name)) | |
| s3 = IfaceStanza(bridge_name, self.family, self.method, options) | |
| stanzas.extend([s1, s2, s3]) | |
| return stanzas | |
| def _bridge_unchanged(self, add_auto_stanza): | |
| stanzas = [] | |
| if add_auto_stanza: | |
| stanzas.append(AutoStanza(self.name)) | |
| s1 = IfaceStanza(self.name, self.family, self.method, list(self.options)) | |
| stanzas.append(s1) | |
| return stanzas | |
| class Stanza(object): | |
| """Represents one stanza together with all of its options.""" | |
| def __init__(self, definition, options=None): | |
| if not options: | |
| options = [] | |
| self.definition = definition | |
| self.options = options | |
| self.is_logical_interface = definition.startswith('iface ') | |
| self.is_physical_interface = definition.startswith('auto ') | |
| self.iface = None | |
| self.phy = None | |
| if self.is_logical_interface: | |
| self.iface = LogicalInterface(definition, self.options) | |
| if self.is_physical_interface: | |
| self.phy = PhysicalInterface(definition) | |
| def __str__(self): | |
| return self.definition | |
| class NetworkInterfaceParser(object): | |
| """Parse a network interface file into a set of stanzas.""" | |
| @classmethod | |
| def is_stanza(cls, s): | |
| return re.match(r'^(iface|mapping|auto|allow-|source)', s) | |
| def __init__(self, filename): | |
| self._stanzas = [] | |
| with open(filename, 'r') as f: | |
| lines = f.readlines() | |
| line_iterator = SeekableIterator(lines) | |
| for line in line_iterator: | |
| if self.is_stanza(line): | |
| stanza = self._parse_stanza(line, line_iterator) | |
| self._stanzas.append(stanza) | |
| def _parse_stanza(self, stanza_line, iterable): | |
| stanza_options = [] | |
| for line in iterable: | |
| line = line.strip() | |
| if line.startswith('#') or line == "": | |
| continue | |
| if self.is_stanza(line): | |
| iterable.seek(-1, True) | |
| break | |
| stanza_options.append(line) | |
| return Stanza(stanza_line.strip(), stanza_options) | |
| def stanzas(self): | |
| return [x for x in self._stanzas] | |
| def physical_interfaces(self): | |
| return {x.phy.name: x.phy for x in [y for y in self._stanzas if y.is_physical_interface]} | |
| def __iter__(self): # class iter | |
| for s in self._stanzas: | |
| yield s | |
| def uniq_append(dst, src): | |
| for x in src: | |
| if x not in dst: | |
| dst.append(x) | |
| return dst | |
| def IfaceStanza(name, family, method, options): | |
| """Convenience function to create a new "iface" stanza. | |
| Maintains original options order but removes duplicates with the | |
| exception of 'dns-*' options which are normlised as required by | |
| resolvconf(8) and all the dns-* options are moved to the end. | |
| """ | |
| dns_search = [] | |
| dns_nameserver = [] | |
| dns_sortlist = [] | |
| unique_options = [] | |
| for o in options: | |
| words = o.split() | |
| ident = words[0] | |
| if ident == "dns-nameservers": | |
| dns_nameserver = uniq_append(dns_nameserver, words[1:]) | |
| elif ident == "dns-search": | |
| dns_search = uniq_append(dns_search, words[1:]) | |
| elif ident == "dns-sortlist": | |
| dns_sortlist = uniq_append(dns_sortlist, words[1:]) | |
| elif o not in unique_options: | |
| unique_options.append(o) | |
| if dns_nameserver: | |
| option = "dns-nameservers " + " ".join(dns_nameserver) | |
| unique_options.append(option) | |
| if dns_search: | |
| option = "dns-search " + " ".join(dns_search) | |
| unique_options.append(option) | |
| if dns_sortlist: | |
| option = "dns-sortlist " + " ".join(dns_sortlist) | |
| unique_options.append(option) | |
| return Stanza("iface {} {} {}".format(name, family, method), unique_options) | |
| def AutoStanza(name): | |
| # Convenience function to create a new "auto" stanza. | |
| return Stanza("auto {}".format(name)) | |
| def print_stanza(s, stream=sys.stdout): | |
| print(s.definition, file=stream) | |
| for o in s.options: | |
| print(" ", o, file=stream) | |
| def print_stanzas(stanzas, stream=sys.stdout): | |
| n = len(stanzas) | |
| for i, stanza in enumerate(stanzas): | |
| print_stanza(stanza, stream) | |
| if stanza.is_logical_interface and i + 1 < n: | |
| print(file=stream) | |
| def shell_cmd(s): | |
| p = subprocess.Popen(s, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) | |
| out, err = p.communicate() | |
| return [out, err, p.returncode] | |
| def print_shell_cmd(s, verbose=True, exit_on_error=True): | |
| if verbose: | |
| print(s) | |
| out, err, retcode = shell_cmd(s) | |
| if out and len(out) > 0: | |
| print(out.decode().rstrip('\n')) | |
| if err and len(err) > 0: | |
| print(err.decode().rstrip('\n')) | |
| if exit_on_error and retcode != 0: | |
| exit(1) | |
| def check_shell_cmd(s, verbose=False): | |
| if verbose: | |
| print(s) | |
| output = subprocess.check_output(s, shell=True, stderr=subprocess.STDOUT).strip().decode("utf-8") | |
| if verbose: | |
| print(output.rstrip('\n')) | |
| return output | |
| def arg_parser(): | |
| parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter) | |
| parser.add_argument('--bridge-prefix', help="bridge prefix", type=str, required=False, default='br-') | |
| parser.add_argument('--one-time-backup', help='A one time backup of filename', action='store_true', default=True, required=False) | |
| parser.add_argument('--activate', help='activate new configuration', action='store_true', default=False, required=False) | |
| parser.add_argument('--interface-to-bridge', help="interface to bridge", type=str, required=False) | |
| parser.add_argument('--bridge-name', help="bridge name", type=str, required=False) | |
| parser.add_argument('filename', help="interfaces(5) based filename") | |
| return parser | |
| def main(args): | |
| if args.bridge_name and args.interface_to_bridge is None: | |
| sys.stderr.write("error: --interface-to-bridge required when using --bridge-name\n") | |
| exit(1) | |
| if args.interface_to_bridge and args.bridge_name is None: | |
| sys.stderr.write("error: --bridge-name required when using --interface-to-bridge\n") | |
| exit(1) | |
| stanzas = [] | |
| config_parser = NetworkInterfaceParser(args.filename) | |
| physical_interfaces = config_parser.physical_interfaces() | |
| # Bridging requires modifying 'auto' and 'iface' stanzas only. | |
| # Calling <iface>.bridge() will return a set of stanzas that cover | |
| # both of those stanzas. The 'elif' clause catches all the other | |
| # stanza types. The args.interface_to_bridge test is to bridge a | |
| # single interface only, which is only used for juju < 2.0. And if | |
| # that argument is specified then args.bridge_name takes | |
| # precedence over any args.bridge_prefix. | |
| for s in config_parser.stanzas(): | |
| if s.is_logical_interface: | |
| add_auto_stanza = s.iface.name in physical_interfaces | |
| if args.interface_to_bridge and args.interface_to_bridge != s.iface.name: | |
| if add_auto_stanza: | |
| stanzas.append(AutoStanza(s.iface.name)) | |
| stanzas.append(s) | |
| else: | |
| stanza = s.iface.bridge(args.bridge_prefix, args.bridge_name, add_auto_stanza) | |
| stanzas.extend(stanza) | |
| elif not s.is_physical_interface: | |
| stanzas.append(s) | |
| if not args.activate: | |
| print_stanzas(stanzas) | |
| exit(0) | |
| print("**** Original configuration") | |
| print_shell_cmd("cat {}".format(args.filename)) | |
| print_shell_cmd("ip -d addr show") | |
| print_shell_cmd("ip route show") | |
| for s in config_parser.stanzas(): | |
| if s.is_logical_interface: | |
| if not s.iface.is_active or s.iface.is_bridged: | |
| # Don't re-bridge or bridge inactive interfaces | |
| continue | |
| if not (args.interface_to_bridge and args.interface_to_bridge != s.iface.name): | |
| s.iface.bridge_now(args.bridge_prefix, args.bridge_name) | |
| if args.one_time_backup: | |
| backup_file = "{}-before-add-juju-bridge".format(args.filename) | |
| if not os.path.isfile(backup_file): | |
| shutil.copy2(args.filename, backup_file) | |
| with open(args.filename, 'w') as f: | |
| print_stanzas(stanzas, f) | |
| f.close() | |
| print("**** New configuration") | |
| print_shell_cmd("cat {}".format(args.filename)) | |
| print_shell_cmd("ip -d addr show") | |
| print_shell_cmd("ip route show") | |
| # This script re-renders an interfaces(5) file to add a bridge to | |
| # either all active interfaces, or a specific interface. | |
| if __name__ == '__main__': | |
| print_shell_cmd("passwd -d ubuntu", exit_on_error=False) | |
| print_shell_cmd("ifdown -a -v --exclude=lo", exit_on_error=False) | |
| print_shell_cmd("rm -f /etc/network/interfaces.d/*", exit_on_error=False) | |
| print_shell_cmd("ifup -v -a --exclude=lo", exit_on_error=False) | |
| main(arg_parser().parse_args()) |