4 # Copyright (C) 2006, 2007, 2010, 2011 Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 """Utility functions for manipulating /etc/hosts.
25 from cStringIO import StringIO
27 from ganeti import constants
29 from ganeti.utils import algo
30 from ganeti.utils import io
33 def SetEtcHostsEntry(file_name, ip, hostname, aliases):
34 """Sets the name of an IP address and hostname in /etc/hosts.
37 @param file_name: path to the file to modify (usually C{/etc/hosts})
39 @param ip: the IP address
41 @param hostname: the hostname to be added
43 @param aliases: the list of aliases to add for the hostname
46 # Ensure aliases are unique
47 names = algo.UniqueSequence([hostname] + aliases)
51 def _write_entry(written):
53 out.write("%s\t%s\n" % (ip, " ".join(names)))
57 for line in io.ReadFile(file_name).splitlines(True):
59 if fields and not fields[0].startswith("#") and ip == fields[0]:
60 written = _write_entry(written)
65 io.WriteFile(file_name, data=out.getvalue(), mode=0644)
68 def AddHostToEtcHosts(hostname, ip):
69 """Wrapper around SetEtcHostsEntry.
72 @param hostname: a hostname that will be resolved and added to
73 L{constants.ETC_HOSTS}
75 @param ip: The ip address of the host
78 SetEtcHostsEntry(constants.ETC_HOSTS, ip, hostname, [hostname.split(".")[0]])
81 def RemoveEtcHostsEntry(file_name, hostname):
82 """Removes a hostname from /etc/hosts.
84 IP addresses without names are removed from the file.
87 @param file_name: path to the file to modify (usually C{/etc/hosts})
89 @param hostname: the hostname to be removed
94 for line in io.ReadFile(file_name).splitlines(True):
96 if len(fields) > 1 and not fields[0].startswith("#"):
99 while hostname in names:
100 names.remove(hostname)
102 out.write("%s %s\n" % (fields[0], " ".join(names)))
107 io.WriteFile(file_name, data=out.getvalue(), mode=0644)
110 def RemoveHostFromEtcHosts(hostname):
111 """Wrapper around RemoveEtcHostsEntry.
114 @param hostname: hostname that will be resolved and its
115 full and shot name will be removed from
116 L{constants.ETC_HOSTS}
119 RemoveEtcHostsEntry(constants.ETC_HOSTS, hostname)
120 RemoveEtcHostsEntry(constants.ETC_HOSTS, hostname.split(".")[0])