From 5fc5da29e5187ff6f56c968e7c06fabd1fce62ad Mon Sep 17 00:00:00 2001

From: Ryan McCabe <rmccabe@redhat.com>

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 <rmccabe@redhat.com>

(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 <rmccabe@redhat.com>

+#

+# 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