164 lines
5.1 KiB
Python
164 lines
5.1 KiB
Python
# Copyright (C) 2012 Yahoo! Inc.
|
|
#
|
|
# Author: Joshua Harlow <harlowja@yahoo-inc.com>
|
|
#
|
|
# This file is part of cloud-init. See LICENSE file for license information.
|
|
|
|
import logging
|
|
from io import StringIO
|
|
|
|
from cloudinit import util
|
|
from cloudinit.distros.parsers import chop_comment
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
# See: man resolv.conf
|
|
class ResolvConf:
|
|
def __init__(self, text):
|
|
self._text = text
|
|
self._contents = None
|
|
|
|
def parse(self):
|
|
if self._contents is None:
|
|
self._contents = self._parse(self._text)
|
|
|
|
@property
|
|
def nameservers(self):
|
|
self.parse()
|
|
return self._retr_option("nameserver")
|
|
|
|
@property
|
|
def local_domain(self):
|
|
self.parse()
|
|
dm = self._retr_option("domain")
|
|
if dm:
|
|
return dm[0]
|
|
return None
|
|
|
|
@local_domain.setter
|
|
def local_domain(self, domain):
|
|
self.parse()
|
|
self._remove_option("domain")
|
|
self._contents.append(("option", ["domain", str(domain), ""]))
|
|
return domain
|
|
|
|
@property
|
|
def search_domains(self):
|
|
self.parse()
|
|
current_sds = self._retr_option("search")
|
|
flat_sds = []
|
|
for sdlist in current_sds:
|
|
for sd in sdlist.split(None):
|
|
if sd:
|
|
flat_sds.append(sd)
|
|
return flat_sds
|
|
|
|
def __str__(self):
|
|
self.parse()
|
|
contents = StringIO()
|
|
for line_type, components in self._contents:
|
|
if line_type == "blank":
|
|
contents.write("\n")
|
|
elif line_type == "all_comment":
|
|
contents.write("%s\n" % (components[0]))
|
|
elif line_type == "option":
|
|
(cfg_opt, cfg_value, comment_tail) = components
|
|
line = "%s %s" % (cfg_opt, cfg_value)
|
|
if len(comment_tail):
|
|
line += comment_tail
|
|
contents.write("%s\n" % (line))
|
|
return contents.getvalue()
|
|
|
|
def _retr_option(self, opt_name):
|
|
found = []
|
|
for line_type, components in self._contents:
|
|
if line_type == "option":
|
|
(cfg_opt, cfg_value, _comment_tail) = components
|
|
if cfg_opt == opt_name:
|
|
found.append(cfg_value)
|
|
return found
|
|
|
|
def add_nameserver(self, ns):
|
|
self.parse()
|
|
current_ns = self._retr_option("nameserver")
|
|
new_ns = list(current_ns)
|
|
new_ns.append(str(ns))
|
|
new_ns = util.uniq_list(new_ns)
|
|
if len(new_ns) == len(current_ns):
|
|
return current_ns
|
|
self._remove_option("nameserver")
|
|
for n in new_ns:
|
|
self._contents.append(("option", ["nameserver", n, ""]))
|
|
return new_ns
|
|
|
|
def _remove_option(self, opt_name):
|
|
def remove_opt(item):
|
|
line_type, components = item
|
|
if line_type != "option":
|
|
return False
|
|
(cfg_opt, _cfg_value, _comment_tail) = components
|
|
if cfg_opt != opt_name:
|
|
return False
|
|
return True
|
|
|
|
new_contents = []
|
|
for c in self._contents:
|
|
if not remove_opt(c):
|
|
new_contents.append(c)
|
|
self._contents = new_contents
|
|
|
|
def add_search_domain(self, search_domain):
|
|
flat_sds = self.search_domains
|
|
new_sds = list(flat_sds)
|
|
new_sds.append(str(search_domain))
|
|
new_sds = util.uniq_list(new_sds)
|
|
if len(flat_sds) == len(new_sds):
|
|
return new_sds
|
|
if len(flat_sds) >= 6:
|
|
# Hard restriction on only 6 search domains
|
|
raise ValueError(
|
|
"Adding %r would go beyond the '6' maximum search domains"
|
|
% (search_domain)
|
|
)
|
|
s_list = " ".join(new_sds)
|
|
if len(s_list) > 256:
|
|
# Some hard limit on 256 chars total
|
|
raise ValueError(
|
|
"Adding %r would go beyond the "
|
|
"256 maximum search list character limit" % (search_domain)
|
|
)
|
|
self._remove_option("search")
|
|
self._contents.append(("option", ["search", s_list, ""]))
|
|
return flat_sds
|
|
|
|
def _parse(self, contents):
|
|
entries = []
|
|
for i, line in enumerate(contents.splitlines()):
|
|
sline = line.strip()
|
|
if not sline:
|
|
entries.append(("blank", [line]))
|
|
continue
|
|
(head, tail) = chop_comment(line, ";#")
|
|
if not len(head.strip()):
|
|
entries.append(("all_comment", [line]))
|
|
continue
|
|
if not tail:
|
|
tail = ""
|
|
try:
|
|
(cfg_opt, cfg_values) = head.split(None, 1)
|
|
except (IndexError, ValueError) as e:
|
|
raise IOError(
|
|
"Incorrectly formatted resolv.conf line %s" % (i + 1)
|
|
) from e
|
|
if cfg_opt not in [
|
|
"nameserver",
|
|
"domain",
|
|
"search",
|
|
"sortlist",
|
|
"options",
|
|
]:
|
|
raise IOError("Unexpected resolv.conf option %s" % (cfg_opt))
|
|
entries.append(("option", [cfg_opt, cfg_values, tail]))
|
|
return entries
|