62a0c15c24
This adds a method 'get_hostname_fqdn' to cloudinit.util, and then uses this method for getting the hostname and fqdn in places that get hostname. The single place for getting it right will help.
96 lines
3.0 KiB
Python
96 lines
3.0 KiB
Python
# vi: ts=4 expandtab
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#
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# Copyright (C) 2011 Canonical Ltd.
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#
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# Author: Scott Moser <scott.moser@canonical.com>
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License version 3, as
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# published by the Free Software Foundation.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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import cloudinit.util as util
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import subprocess
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import errno
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from cloudinit.CloudConfig import per_always
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frequency = per_always
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def handle(name,cfg,cloud,log,args):
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if util.get_cfg_option_bool(cfg,"preserve_hostname",False):
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log.debug("preserve_hostname is set. not updating hostname")
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return
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( hostname, fqdn ) = util.get_hostname_fqdn(cfg, cloud)
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try:
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prev ="%s/%s" % (cloud.get_cpath('data'),"previous-hostname")
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update_hostname(hostname, prev, log)
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except Exception as e:
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log.warn("failed to set hostname\n")
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raise
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# read hostname from a 'hostname' file
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# allow for comments and stripping line endings.
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# if file doesn't exist, or no contents, return default
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def read_hostname(filename, default=None):
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try:
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fp = open(filename,"r")
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lines = fp.readlines()
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fp.close()
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for line in lines:
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hpos = line.find("#")
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if hpos != -1:
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line = line[0:hpos]
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line = line.rstrip()
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if line:
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return line
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except IOError as e:
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if e.errno != errno.ENOENT: raise
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return default
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def update_hostname(hostname, prev_file, log):
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etc_file = "/etc/hostname"
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hostname_prev = None
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hostname_in_etc = None
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try:
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hostname_prev = read_hostname(prev_file)
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except Exception as e:
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log.warn("Failed to open %s: %s" % (prev_file, e))
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try:
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hostname_in_etc = read_hostname(etc_file)
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except:
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log.warn("Failed to open %s" % etc_file)
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update_files = []
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if not hostname_prev or hostname_prev != hostname:
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update_files.append(prev_file)
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if (not hostname_in_etc or
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(hostname_in_etc == hostname_prev and hostname_in_etc != hostname)):
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update_files.append(etc_file)
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try:
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for fname in update_files:
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util.write_file(fname,"%s\n" % hostname, 0644)
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log.debug("wrote %s to %s" % (hostname,fname))
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except:
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log.warn("failed to write hostname to %s" % fname)
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if hostname_in_etc and hostname_prev and hostname_in_etc != hostname_prev:
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log.debug("%s differs from %s. assuming user maintained" %
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(prev_file,etc_file))
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if etc_file in update_files:
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log.debug("setting hostname to %s" % hostname)
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subprocess.Popen(['hostname', hostname]).communicate()
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