net: recognize iscsi root cases without ip= on kernel command line.

When 'ip=' or 'ip6=' is found on the kernel command line,
cloud-init will consider read network config from /run/net-*.conf files.

There are some iscsi-root scenarios where initramfs configures networking
but the ip= parameter is not present. 2 such cases are:
 a.) static config in /etc/iscsi/iscsi.initramfs (copied into the
initramfs)
 b.) iBft

This changes cloud-init to consider initramfs provided networking
information if:
 * there are /run/net-* files and
 * (ip= or ip6 is on the command line) or open-iscsi.interface file
exists.

LP: #1752391

1 files changed, 43 insertions, 18 deletions

diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py
index 9cf11f2e..84a0eabf 100644
--- a/tests/unittests/test_net.py
+++ b/tests/unittests/test_net.py
@@ -12,10 +12,8 @@ from cloudinit.sources.helpers import openstack
 from cloudinit import temp_utils
 from cloudinit import util
 
-from cloudinit.tests.helpers import CiTestCase
-from cloudinit.tests.helpers import dir2dict
-from cloudinit.tests.helpers import mock
-from cloudinit.tests.helpers import populate_dir
+from cloudinit.tests.helpers import (
+    CiTestCase, FilesystemMockingTestCase, dir2dict, mock, populate_dir)
 
 import base64
 import copy
@@ -2186,27 +2184,49 @@ class TestCmdlineConfigParsing(CiTestCase):
         self.assertEqual(found, self.simple_cfg)
 
 
-class TestCmdlineReadKernelConfig(CiTestCase):
+class TestCmdlineReadKernelConfig(FilesystemMockingTestCase):
     macs = {
         'eth0': '14:02:ec:42:48:00',
         'eno1': '14:02:ec:42:48:01',
     }
 
-    def test_ip_cmdline_read_kernel_cmdline_ip(self):
-        content = {'net-eth0.conf': DHCP_CONTENT_1}
-        files = sorted(populate_dir(self.tmp_dir(), content))
+    def test_ip_cmdline_without_ip(self):
+        content = {'/run/net-eth0.conf': DHCP_CONTENT_1,
+                   cmdline._OPEN_ISCSI_INTERFACE_FILE: "eth0\n"}
+        exp1 = copy.deepcopy(DHCP_EXPECTED_1)
+        exp1['mac_address'] = self.macs['eth0']
+
+        root = self.tmp_dir()
+        populate_dir(root, content)
+        self.reRoot(root)
+
         found = cmdline.read_kernel_cmdline_config(
-            files=files, cmdline='foo ip=dhcp', mac_addrs=self.macs)
+            cmdline='foo root=/root/bar', mac_addrs=self.macs)
+        self.assertEqual(found['version'], 1)
+        self.assertEqual(found['config'], [exp1])
+
+    def test_ip_cmdline_read_kernel_cmdline_ip(self):
+        content = {'/run/net-eth0.conf': DHCP_CONTENT_1}
         exp1 = copy.deepcopy(DHCP_EXPECTED_1)
         exp1['mac_address'] = self.macs['eth0']
+
+        root = self.tmp_dir()
+        populate_dir(root, content)
+        self.reRoot(root)
+
+        found = cmdline.read_kernel_cmdline_config(
+            cmdline='foo ip=dhcp', mac_addrs=self.macs)
         self.assertEqual(found['version'], 1)
         self.assertEqual(found['config'], [exp1])
 
     def test_ip_cmdline_read_kernel_cmdline_ip6(self):
-        content = {'net6-eno1.conf': DHCP6_CONTENT_1}
-        files = sorted(populate_dir(self.tmp_dir(), content))
+        content = {'/run/net6-eno1.conf': DHCP6_CONTENT_1}
+        root = self.tmp_dir()
+        populate_dir(root, content)
+        self.reRoot(root)
+
         found = cmdline.read_kernel_cmdline_config(
-            files=files, cmdline='foo ip6=dhcp root=/dev/sda',
+            cmdline='foo ip6=dhcp root=/dev/sda',
             mac_addrs=self.macs)
         self.assertEqual(
             found,
@@ -2226,18 +2246,23 @@ class TestCmdlineReadKernelConfig(CiTestCase):
         self.assertIsNone(found)
 
     def test_ip_cmdline_both_ip_ip6(self):
-        content = {'net-eth0.conf': DHCP_CONTENT_1,
-                   'net6-eth0.conf': DHCP6_CONTENT_1.replace('eno1', 'eth0')}
-        files = sorted(populate_dir(self.tmp_dir(), content))
-        found = cmdline.read_kernel_cmdline_config(
-            files=files, cmdline='foo ip=dhcp ip6=dhcp', mac_addrs=self.macs)
-
+        content = {
+            '/run/net-eth0.conf': DHCP_CONTENT_1,
+            '/run/net6-eth0.conf': DHCP6_CONTENT_1.replace('eno1', 'eth0')}
         eth0 = copy.deepcopy(DHCP_EXPECTED_1)
         eth0['mac_address'] = self.macs['eth0']
         eth0['subnets'].append(
             {'control': 'manual', 'type': 'dhcp6',
              'netmask': '64', 'dns_nameservers': ['2001:67c:1562:8010::2:1']})
         expected = [eth0]
+
+        root = self.tmp_dir()
+        populate_dir(root, content)
+        self.reRoot(root)
+
+        found = cmdline.read_kernel_cmdline_config(
+            cmdline='foo ip=dhcp ip6=dhcp', mac_addrs=self.macs)
+
         self.assertEqual(found['version'], 1)
         self.assertEqual(found['config'], expected)