From 4aa2305022e5d42d858102941c51d7186ef8fef9 Mon Sep 17 00:00:00 2001

From: Scott Moser <smoser@brickies.net>

Date: Wed, 15 Mar 2017 12:06:40 -0400

Subject: [PATCH 1/3] support 'loopback' as a device type.

As reported in bug 1671927, sysconfig had an issue with rendering

a loopback device.  The problem was that some as yet unknown issue was

causing the openstack config drive to parse the provided ENI file rather

than reading the network_data.json.  Parsing an ENI file would add a

a 'lo' device of type 'physical', and sysconfig was failing to render

that.

The change here is:

 a.) add a 'loopback' type rather than 'physical' for network config.

     {'name': 'lo', 'type': 'loopback', 'subnets': ['type': 'loopback']}

 b.) support skipping that type in the eni and sysconfig renderers.

 c.) make network_state just piggy back on 'physical' renderer for

     loopback (this was what was happening before).

Tests are added for eni and sysconfig renderer.

(cherry picked from commit 1a2ca7530518d819cbab7287b12f942743427e38)

Related: rhbz#1540094

---

 cloudinit/net/eni.py           | 16 +++++++++------

 cloudinit/net/network_state.py |  4 ++++

 cloudinit/net/sysconfig.py     |  2 ++

 tests/unittests/test_net.py    | 44 ++++++++++++++++++++++++++++++++++++++++++

 4 files changed, 60 insertions(+), 6 deletions(-)

diff --git a/cloudinit/net/eni.py b/cloudinit/net/eni.py

index b06ffac9..0d5e9712 100644

--- a/cloudinit/net/eni.py

+++ b/cloudinit/net/eni.py

@@ -265,8 +265,11 @@ def _ifaces_to_net_config_data(ifaces):

         # devname is 'eth0' for name='eth0:1'

         devname = name.partition(":")[0]

         if devname not in devs:

-            devs[devname] = {'type': 'physical', 'name': devname,

-                             'subnets': []}

+            if devname == "lo":

+                dtype = "loopback"

+            else:

+                dtype = "physical"

+            devs[devname] = {'type': dtype, 'name': devname, 'subnets': []}

             # this isnt strictly correct, but some might specify

             # hwaddress on a nic for matching / declaring name.

             if 'hwaddress' in data:

@@ -418,10 +421,11 @@ class Renderer(renderer.Renderer):

             bonding

         '''

         order = {

-            'physical': 0,

-            'bond': 1,

-            'bridge': 2,

-            'vlan': 3,

+            'loopback': 0,

+            'physical': 1,

+            'bond': 2,

+            'bridge': 3,

+            'vlan': 4,

         }

         sections = []

diff --git a/cloudinit/net/network_state.py b/cloudinit/net/network_state.py

index 11ef585b..90b2835a 100644

--- a/cloudinit/net/network_state.py

+++ b/cloudinit/net/network_state.py

@@ -211,6 +211,10 @@ class NetworkStateInterpreter(object):

                              exc_info=True)

                     LOG.debug(self.dump_network_state())

+    @ensure_command_keys(['name'])

+    def handle_loopback(self, command):

+        return self.handle_physical(command)

+

     @ensure_command_keys(['name'])

     def handle_physical(self, command):

         '''

diff --git a/cloudinit/net/sysconfig.py b/cloudinit/net/sysconfig.py

index efd101ca..25c29104 100644

--- a/cloudinit/net/sysconfig.py

+++ b/cloudinit/net/sysconfig.py

@@ -500,6 +500,8 @@ class Renderer(renderer.Renderer):

         '''Given state, return /etc/sysconfig files + contents'''

         iface_contents = {}

         for iface in network_state.iter_interfaces():

+            if iface['type'] == "loopback":

+                continue

             iface_name = iface['name']

             iface_cfg = NetInterface(iface_name, base_sysconf_dir)

             cls._render_iface_shared(iface, iface_cfg)

diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py

index ffa911cc..d75742be 100644

--- a/tests/unittests/test_net.py

+++ b/tests/unittests/test_net.py

@@ -600,6 +600,14 @@ pre-down route del -net 10.0.0.0 netmask 255.0.0.0 gw 11.0.0.1 metric 3 || true

     }

 }

+CONFIG_V1_EXPLICIT_LOOPBACK = {

+    'version': 1,

+    'config': [{'name': 'eth0', 'type': 'physical',

+               'subnets': [{'control': 'auto', 'type': 'dhcp'}]},

+               {'name': 'lo', 'type': 'loopback',

+                'subnets': [{'control': 'auto', 'type': 'loopback'}]},

+               ]}

+

 def _setup_test(tmp_dir, mock_get_devicelist, mock_read_sys_net,

                 mock_sys_dev_path):

@@ -770,6 +778,27 @@ USERCTL=no

                 with open(os.path.join(render_dir, fn)) as fh:

                     self.assertEqual(expected_content, fh.read())

+    def test_config_with_explicit_loopback(self):

+        ns = network_state.parse_net_config_data(CONFIG_V1_EXPLICIT_LOOPBACK)

+        render_dir = self.tmp_path("render")

+        os.makedirs(render_dir)

+        renderer = sysconfig.Renderer()

+        renderer.render_network_state(render_dir, ns)

+        found = dir2dict(render_dir)

+        nspath = '/etc/sysconfig/network-scripts/'

+        self.assertNotIn(nspath + 'ifcfg-lo', found.keys())

+        expected = """\

+# Created by cloud-init on instance boot automatically, do not edit.

+#

+BOOTPROTO=dhcp

+DEVICE=eth0

+NM_CONTROLLED=no

+ONBOOT=yes

+TYPE=Ethernet

+USERCTL=no

+"""

+        self.assertEqual(expected, found[nspath + 'ifcfg-eth0'])

+

 class TestEniNetRendering(TestCase):

@@ -811,6 +840,21 @@ iface eth1000 inet dhcp

 """

         self.assertEqual(expected.lstrip(), contents.lstrip())

+    def test_config_with_explicit_loopback(self):

+        tmp_dir = self.tmp_dir()

+        ns = network_state.parse_net_config_data(CONFIG_V1_EXPLICIT_LOOPBACK)

+        renderer = eni.Renderer()

+        renderer.render_network_state(tmp_dir, ns)

+        expected = """\

+auto lo

+iface lo inet loopback

+

+auto eth0

+iface eth0 inet dhcp

+"""

+        self.assertEqual(

+            expected, dir2dict(tmp_dir)['/etc/network/interfaces'])

+

 class TestEniNetworkStateToEni(TestCase):

     mycfg = {

-- 

2.14.3