diff options
| -rw-r--r-- | cloudinit/config/cc_resolv_conf.py | 107 | ||||
| -rw-r--r-- | doc/examples/cloud-config-resolv-conf.txt | 20 | ||||
| -rw-r--r-- | templates/resolv.conf.tmpl | 39 |
3 files changed, 166 insertions, 0 deletions
diff --git a/cloudinit/config/cc_resolv_conf.py b/cloudinit/config/cc_resolv_conf.py new file mode 100644 index 00000000..17c74695 --- /dev/null +++ b/cloudinit/config/cc_resolv_conf.py @@ -0,0 +1,107 @@ +# vi: ts=4 expandtab +# +# Copyright (C) 2013 Craig Tracey +# +# Author: Craig Tracey <craigtracey@gmail.com> +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 3, as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +# Note: +# This module is intended to manage resolv.conf in environments where +# early configuration of resolv.conf is necessary for further +# bootstrapping and/or where configuration management such as puppet or +# chef own dns configuration. As Debian/Ubuntu will, by default, utilize +# resovlconf, and similarly RedHat will use sysconfig, this module is +# likely to be of little use unless those are configured correctly. +# +# For RedHat with sysconfig, be sure to set PEERDNS=no for all DHCP +# enabled NICs. And, in Ubuntu/Debian it is recommended that DNS +# be configured via the standard /etc/network/interfaces configuration +# file. +# +# +# Usage Example: +# +# #cloud-config +# manage_resolv_conf: true +# +# resolv_conf: +# nameservers: ['8.8.4.4', '8.8.8.8'] +# searchdomains: +# - foo.example.com +# - bar.example.com +# domain: example.com +# options: +# rotate: true +# timeout: 1 +# + + +from cloudinit.settings import PER_ONCE +from cloudinit import templater +from cloudinit import util + +frequency = PER_ONCE + +distros = ['fedora', 'rhel'] + + +def generate_resolv_conf(cloud, log, params): + template_fn = cloud.get_template_filename('resolv.conf') + if not template_fn: + log.warn("No template found, not rendering /etc/resolv.conf") + return + + flags = [] + false_flags = [] + if 'options' in params: + for key, val in params['options'].iteritems(): + if type(val) == bool: + if val: + flags.append(key) + else: + false_flags.append(key) + + for flag in flags + false_flags: + del params['options'][flag] + + params['flags'] = flags + log.debug("Writing resolv.conf from template %s" % template_fn) + templater.render_to_file(template_fn, '/etc/resolv.conf', params) + + +def handle(name, cfg, _cloud, log, _args): + """ + Handler for resolv.conf + + @param name: The module name "resolv-conf" from cloud.cfg + @param cfg: A nested dict containing the entire cloud config contents. + @param cloud: The L{CloudInit} object in use. + @param log: Pre-initialized Python logger object to use for logging. + @param args: Any module arguments from cloud.cfg + """ + if "manage_resolv_conf" not in cfg: + log.debug(("Skipping module named %s," + " no 'manage_resolv_conf' key in configuration"), name) + return + + if not util.get_cfg_option_bool(cfg, "manage_resolv_conf", False): + log.debug(("Skipping module named %s," + " 'manage_resolv_conf' present but set to False"), name) + return + + if not "resolv_conf" in cfg: + log.warn("manage_resolv_conf True but no parameters provided!") + + generate_resolv_conf(_cloud, log, cfg["resolv_conf"]) + return diff --git a/doc/examples/cloud-config-resolv-conf.txt b/doc/examples/cloud-config-resolv-conf.txt new file mode 100644 index 00000000..37ffc91a --- /dev/null +++ b/doc/examples/cloud-config-resolv-conf.txt @@ -0,0 +1,20 @@ +#cloud-config +# +# This is an example file to automatically configure resolv.conf when the +# instance boots for the first time. +# +# Ensure that your yaml is valid and pass this as user-data when starting +# the instance. Also be sure that your cloud.cfg file includes this +# configuration module in the appropirate section. +# +manage-resolv-conf: true + +resolv_conf: + nameservers: ['8.8.4.4', '8.8.8.8'] + searchdomains: + - foo.example.com + - bar.example.com + domain: example.com + options: + rotate: true + timeout: 1 diff --git a/templates/resolv.conf.tmpl b/templates/resolv.conf.tmpl new file mode 100644 index 00000000..b7e97b13 --- /dev/null +++ b/templates/resolv.conf.tmpl @@ -0,0 +1,39 @@ +# +# Your system has been configured with 'manage-resolv-conf' set to true. +# As a result, cloud-init has written this file with configuration data +# that it has been provided. Cloud-init, by default, will write this file +# a single time (PER_ONCE). +# + +#if $varExists('nameservers') +#for $server in $nameservers +nameserver $server +#end for +#end if +#if $varExists('searchdomains') +search #slurp +#for $search in $searchdomains +$search #slurp +#end for + +#end if +#if $varExists('domain') +domain $domain +#end if +#if $varExists('sortlist') +sortlist #slurp +#for $sort in $sortlist +$sort #slurp +#end for + +#end if +#if $varExists('options') or $varExists('flags') +options #slurp +#for $flag in $flags +$flag #slurp +#end for +#for $key, $value in $options.items() +$key:$value #slurp +#end for + +#end if |