113 lines
3.8 KiB
Python
113 lines
3.8 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 re
|
|
import shlex
|
|
from io import StringIO
|
|
|
|
# This library is used to parse/write
|
|
# out the various sysconfig files edited (best attempt effort)
|
|
#
|
|
# It has to be slightly modified though
|
|
# to ensure that all values are quoted/unquoted correctly
|
|
# since these configs are usually sourced into
|
|
# bash scripts...
|
|
import configobj
|
|
|
|
# See: http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html
|
|
# or look at the 'param_expand()' function in the subst.c file in the bash
|
|
# source tarball...
|
|
SHELL_VAR_RULE = r"[a-zA-Z_]+[a-zA-Z0-9_]*"
|
|
|
|
|
|
def _contains_shell_variable(text):
|
|
for r in [
|
|
# Basic variables
|
|
re.compile(r"\$" + SHELL_VAR_RULE),
|
|
# Things like $?, $0, $-, $@
|
|
re.compile(r"\$[0-9#\?\-@\*]"),
|
|
# Things like ${blah:1} - but this one
|
|
# gets very complex so just try the
|
|
# simple path
|
|
re.compile(r"\$\{.+\}"),
|
|
]:
|
|
if r.search(text):
|
|
return True
|
|
return False
|
|
|
|
|
|
class SysConf(configobj.ConfigObj):
|
|
"""A configobj.ConfigObj subclass specialised for sysconfig files.
|
|
|
|
:param contents:
|
|
The sysconfig file to parse, in a format accepted by
|
|
``configobj.ConfigObj.__init__`` (i.e. "a filename, file like object,
|
|
or list of lines").
|
|
"""
|
|
|
|
def __init__(self, contents):
|
|
configobj.ConfigObj.__init__(
|
|
self, contents, interpolation=False, write_empty_values=True
|
|
)
|
|
|
|
def __str__(self):
|
|
contents = self.write()
|
|
out_contents = StringIO()
|
|
if isinstance(contents, (list, tuple)):
|
|
out_contents.write("\n".join(contents))
|
|
else:
|
|
out_contents.write(str(contents))
|
|
return out_contents.getvalue()
|
|
|
|
def _quote(self, value, multiline=False):
|
|
if not isinstance(value, str):
|
|
raise ValueError('Value "%s" is not a string' % (value))
|
|
if not value:
|
|
return ""
|
|
quot_func = None
|
|
if value[0] in ['"', "'"] and value[-1] in ['"', "'"]:
|
|
if len(value) == 1:
|
|
quot_func = (
|
|
lambda x: self._get_single_quote(x) % x
|
|
) # noqa: E731
|
|
else:
|
|
# Quote whitespace if it isn't the start + end of a shell command
|
|
if value.strip().startswith("$(") and value.strip().endswith(")"):
|
|
pass
|
|
else:
|
|
if re.search(r"[\t\r\n ]", value):
|
|
if _contains_shell_variable(value):
|
|
# If it contains shell variables then we likely want to
|
|
# leave it alone since the shlex.quote function likes
|
|
# to use single quotes which won't get expanded...
|
|
if re.search(r"[\n\"']", value):
|
|
quot_func = (
|
|
lambda x: self._get_triple_quote(x) % x
|
|
) # noqa: E731
|
|
else:
|
|
quot_func = (
|
|
lambda x: self._get_single_quote(x) % x
|
|
) # noqa: E731
|
|
else:
|
|
quot_func = shlex.quote
|
|
if not quot_func:
|
|
return value
|
|
return quot_func(value)
|
|
|
|
def _write_line(self, indent_string, entry, this_entry, comment):
|
|
# Ensure it is formatted fine for
|
|
# how these sysconfig scripts are used
|
|
val = self._decode_element(self._quote(this_entry))
|
|
key = self._decode_element(self._quote(entry))
|
|
cmnt = self._decode_element(comment)
|
|
return "%s%s%s%s%s" % (
|
|
indent_string,
|
|
key,
|
|
"=",
|
|
val,
|
|
cmnt,
|
|
)
|