# 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.
from six import StringIO
from cloudinit.distros.parsers import chop_comment
# Parser that knows how to work with /etc/hostname format
class HostnameConf(object):
def __init__(self, text):
self._text = text
self._contents = None
def parse(self):
if self._contents is None:
self._contents = self._parse(self._text)
def __str__(self):
self.parse()
contents = StringIO()
for (line_type, components) in self._contents:
if line_type == 'blank':
contents.write("%s\n" % (components[0]))
elif line_type == 'all_comment':
contents.write("%s\n" % (components[0]))
elif line_type == 'hostname':
(hostname, tail) = components
contents.write("%s%s\n" % (hostname, tail))
# Ensure trailing newline
contents = contents.getvalue()
if not contents.endswith("\n"):
contents += "\n"
return contents
@property
def hostname(self):
self.parse()
for (line_type, components) in self._contents:
if line_type == 'hostname':
return components[0]
return None
def set_hostname(self, your_hostname):
your_hostname = your_hostname.strip()
if not your_hostname:
return
self.parse()
replaced = False
for (line_type, components) in self._contents:
if line_type == 'hostname':
components[0] = str(your_hostname)
replaced = True
if not replaced:
self._contents.append(('hostname', [str(your_hostname), '']))
def _parse(self, contents):
entries = []
hostnames_found = set()
for line in contents.splitlines():
if not len(line.strip()):
entries.append(('blank', [line]))
continue
(head, tail) = chop_comment(line.strip(), '#')
if not len(head):
entries.append(('all_comment', [line]))
continue
entries.append(('hostname', [head, tail]))
hostnames_found.add(head)
if len(hostnames_found) > 1:
raise IOError("Multiple hostnames (%s) found!"
% (hostnames_found))
return entries
# vi: ts=4 expandtab