From 54e87eaad7841270e530beff2dcfe68292ae87ef Mon Sep 17 00:00:00 2001
From: Ani Sinha <anisinha@redhat.com>
Date: Tue, 21 Nov 2023 13:57:15 +0530
Subject: [PATCH] net: allow dhcp6 configuration from
 generate_fallback_configuration()

This will make sure on Azure we can use both dhcp4 and dhcp6 when IMDS is not
used. This is useful in situations where only ipv6 network is available and
there is no dhcp4 running.

This change is mostly a reversal of commit 29ed5f5b646ee and therefore,
re-application of the commit 518047aea9 with some small changes.

The issue that caused the reversal of 518047aea9 is fixed by the earlier commit:
cab0eaf290af7 ("net/network_manager: do not set "may-fail" to False for both ipv4 and ipv6 dhcp")

Fixes GH-4439

Signed-off-by: Ani Sinha <anisinha@redhat.com>
(cherry picked from commit 0264e969166846b2f5cf87ccdb051a3a795eca15)
---
 cloudinit/net/__init__.py        |  7 ++++++-
 tests/unittests/net/test_init.py |  4 ++++
 tests/unittests/test_net.py      | 24 +++++++++++++++++++++---
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index bf21633b..c0888f52 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -571,7 +571,12 @@ def generate_fallback_config(config_driver=None):
         match = {
             "macaddress": read_sys_net_safe(target_name, "address").lower()
         }
-    cfg = {"dhcp4": True, "set-name": target_name, "match": match}
+    cfg = {
+        "dhcp4": True,
+        "dhcp6": True,
+        "set-name": target_name,
+        "match": match,
+    }
     if config_driver:
         driver = device_driver(target_name)
         if driver:
diff --git a/tests/unittests/net/test_init.py b/tests/unittests/net/test_init.py
index 561d5151..60a44186 100644
--- a/tests/unittests/net/test_init.py
+++ b/tests/unittests/net/test_init.py
@@ -261,6 +261,7 @@ class TestGenerateFallbackConfig(CiTestCase):
                 "eth1": {
                     "match": {"macaddress": mac},
                     "dhcp4": True,
+                    "dhcp6": True,
                     "set-name": "eth1",
                 }
             },
@@ -278,6 +279,7 @@ class TestGenerateFallbackConfig(CiTestCase):
                 "eth0": {
                     "match": {"macaddress": mac},
                     "dhcp4": True,
+                    "dhcp6": True,
                     "set-name": "eth0",
                 }
             },
@@ -293,6 +295,7 @@ class TestGenerateFallbackConfig(CiTestCase):
             "ethernets": {
                 "eth0": {
                     "dhcp4": True,
+                    "dhcp6": True,
                     "match": {"macaddress": mac},
                     "set-name": "eth0",
                 }
@@ -359,6 +362,7 @@ class TestGenerateFallbackConfig(CiTestCase):
             "ethernets": {
                 "ens3": {
                     "dhcp4": True,
+                    "dhcp6": True,
                     "match": {"name": "ens3"},
                     "set-name": "ens3",
                 }
diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py
index fb4c863c..d9ef493b 100644
--- a/tests/unittests/test_net.py
+++ b/tests/unittests/test_net.py
@@ -4339,6 +4339,7 @@ class TestGenerateFallbackConfig(CiTestCase):
             "ethernets": {
                 "eth0": {
                     "dhcp4": True,
+                    "dhcp6": True,
                     "set-name": "eth0",
                     "match": {
                         "macaddress": "00:11:22:33:44:55",
@@ -4423,6 +4424,9 @@ iface lo inet loopback
 
 auto eth0
 iface eth0 inet dhcp
+
+# control-alias eth0
+iface eth0 inet6 dhcp
 """
         self.assertEqual(expected.lstrip(), contents.lstrip())
 
@@ -4512,6 +4516,9 @@ iface lo inet loopback
 
 auto eth1
 iface eth1 inet dhcp
+
+# control-alias eth1
+iface eth1 inet6 dhcp
 """
         self.assertEqual(expected.lstrip(), contents.lstrip())
 
@@ -4736,7 +4743,9 @@ class TestRhelSysConfigRendering(CiTestCase):
 AUTOCONNECT_PRIORITY=120
 BOOTPROTO=dhcp
 DEVICE=eth1000
+DHCPV6C=yes
 HWADDR=07-1c-c6-75-a4-be
+IPV6INIT=yes
 ONBOOT=yes
 TYPE=Ethernet
 USERCTL=no
@@ -5646,7 +5655,8 @@ class TestOpenSuseSysConfigRendering(CiTestCase):
             expected_content = """
 # Created by cloud-init automatically, do not edit.
 #
-BOOTPROTO=dhcp4
+BOOTPROTO=dhcp
+DHCLIENT6_MODE=managed
 LLADDR=07-1c-c6-75-a4-be
 STARTMODE=auto
 """.lstrip()
@@ -6032,7 +6042,11 @@ class TestNetworkManagerRendering(CiTestCase):
 
                 [ipv4]
                 method=auto
-                may-fail=false
+                may-fail=true
+
+                [ipv6]
+                method=auto
+                may-fail=true
 
                 """
                 ),
@@ -6298,6 +6312,9 @@ iface lo inet loopback
 
 auto eth1000
 iface eth1000 inet dhcp
+
+# control-alias eth1000
+iface eth1000 inet6 dhcp
 """
         self.assertEqual(expected.lstrip(), contents.lstrip())
 
@@ -6357,6 +6374,7 @@ class TestNetplanNetRendering:
                   ethernets:
                     eth1000:
                       dhcp4: true
+                      dhcp6: true
                       match:
                         macaddress: 07-1c-c6-75-a4-be
                       set-name: eth1000
@@ -7856,7 +7874,7 @@ class TestNetworkdNetRendering(CiTestCase):
             Name=eth1000
             MACAddress=07-1c-c6-75-a4-be
             [Network]
-            DHCP=ipv4"""
+            DHCP=yes"""
         ).rstrip(" ")
 
         expected = self.create_conf_dict(expected.splitlines())