From 5fc5da29e5187ff6f56c968e7c06fabd1fce62ad Mon Sep 17 00:00:00 2001 From: Ryan McCabe Date: Thu, 8 Jun 2017 13:24:23 -0400 Subject: [PATCH] net: Allow for NetworkManager configuration In cases where the config json specifies nameserver entries, if there are interfaces configured to use dhcp, NetworkManager, if enabled, will clobber the /etc/resolv.conf that cloud-init has produced, which can break dns. If there are no interfaces configured to use dhcp, NetworkManager could clobber /etc/resolv.conf with an empty file. This patch adds a mechanism for dropping additional configuration into /etc/NetworkManager/conf.d/ and disables management of /etc/resolv.conf by NetworkManager when nameserver information is provided in the config. LP: #1693251 Resolves: rhbz#1454491 Signed-off-by: Ryan McCabe (cherry picked from commit 67bab5bb804e2346673430868935f6bbcdb88f13) --- cloudinit/distros/parsers/networkmanager_conf.py | 23 +++++++++++++++++++++++ cloudinit/net/sysconfig.py | 24 ++++++++++++++++++++++++ tests/unittests/test_net.py | 21 +++++++++++++++++++++ 3 files changed, 68 insertions(+) create mode 100644 cloudinit/distros/parsers/networkmanager_conf.py diff --git a/cloudinit/distros/parsers/networkmanager_conf.py b/cloudinit/distros/parsers/networkmanager_conf.py new file mode 100644 index 00000000..ac51f122 --- /dev/null +++ b/cloudinit/distros/parsers/networkmanager_conf.py @@ -0,0 +1,23 @@ +# Copyright (C) 2017 Red Hat, Inc. +# +# Author: Ryan McCabe +# +# This file is part of cloud-init. See LICENSE file for license information. + +import configobj + +# This module is used to set additional NetworkManager configuration +# in /etc/NetworkManager/conf.d +# + + +class NetworkManagerConf(configobj.ConfigObj): + def __init__(self, contents): + configobj.ConfigObj.__init__(self, contents, + interpolation=False, + write_empty_values=False) + + def set_section_keypair(self, section_name, key, value): + if section_name not in self.sections: + self.main[section_name] = {} + self.main[section_name] = {key: value} diff --git a/cloudinit/net/sysconfig.py b/cloudinit/net/sysconfig.py index ef80d99b..d496d916 100644 --- a/cloudinit/net/sysconfig.py +++ b/cloudinit/net/sysconfig.py @@ -5,6 +5,7 @@ import re import six +from cloudinit.distros.parsers import networkmanager_conf from cloudinit.distros.parsers import resolv_conf from cloudinit import util @@ -250,6 +251,9 @@ class Renderer(renderer.Renderer): self.netrules_path = config.get( 'netrules_path', 'etc/udev/rules.d/70-persistent-net.rules') self.dns_path = config.get('dns_path', 'etc/resolv.conf') + nm_conf_path = 'etc/NetworkManager/conf.d/99-cloud-init.conf' + self.networkmanager_conf_path = config.get('networkmanager_conf_path', + nm_conf_path) @classmethod def _render_iface_shared(cls, iface, iface_cfg): @@ -443,6 +447,21 @@ class Renderer(renderer.Renderer): content.add_search_domain(searchdomain) return "\n".join([_make_header(';'), str(content)]) + @staticmethod + def _render_networkmanager_conf(network_state): + content = networkmanager_conf.NetworkManagerConf("") + + # If DNS server information is provided, configure + # NetworkManager to not manage dns, so that /etc/resolv.conf + # does not get clobbered. + if network_state.dns_nameservers: + content.set_section_keypair('main', 'dns', 'none') + + if len(content) == 0: + return None + out = "".join([_make_header(), "\n", "\n".join(content.write()), "\n"]) + return out + @classmethod def _render_bridge_interfaces(cls, network_state, iface_contents): bridge_filter = renderer.filter_by_type('bridge') @@ -500,6 +519,11 @@ class Renderer(renderer.Renderer): resolv_content = self._render_dns(network_state, existing_dns_path=dns_path) util.write_file(dns_path, resolv_content) + if self.networkmanager_conf_path: + nm_conf_path = os.path.join(target, self.networkmanager_conf_path) + nm_conf_content = self._render_networkmanager_conf(network_state) + if nm_conf_content: + util.write_file(nm_conf_path, nm_conf_content) if self.netrules_path: netrules_content = self._render_persistent_net(network_state) netrules_path = os.path.join(target, self.netrules_path) diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py index 172d6046..379ac8bb 100755 --- a/tests/unittests/test_net.py +++ b/tests/unittests/test_net.py @@ -162,6 +162,13 @@ NETMASK0=0.0.0.0 ; nameserver 172.19.0.12 """.lstrip()), + ('etc/NetworkManager/conf.d/99-cloud-init.conf', + """ +# Created by cloud-init on instance boot automatically, do not edit. +# +[main] +dns = none +""".lstrip()), ('etc/udev/rules.d/70-persistent-net.rules', "".join(['SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ', 'ATTR{address}=="fa:16:3e:ed:9a:59", NAME="eth0"\n']))] @@ -222,6 +229,13 @@ USERCTL=no ; nameserver 172.19.0.12 """.lstrip()), + ('etc/NetworkManager/conf.d/99-cloud-init.conf', + """ +# Created by cloud-init on instance boot automatically, do not edit. +# +[main] +dns = none +""".lstrip()), ('etc/udev/rules.d/70-persistent-net.rules', "".join(['SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ', 'ATTR{address}=="fa:16:3e:ed:9a:59", NAME="eth0"\n']))] @@ -304,6 +318,13 @@ USERCTL=no ; nameserver 172.19.0.12 """.lstrip()), + ('etc/NetworkManager/conf.d/99-cloud-init.conf', + """ +# Created by cloud-init on instance boot automatically, do not edit. +# +[main] +dns = none +""".lstrip()), ('etc/udev/rules.d/70-persistent-net.rules', "".join(['SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ', 'ATTR{address}=="fa:16:3e:ed:9a:59", NAME="eth0"\n']))] -- 2.13.6