From 518047aea93d502aefae808921b11d0cfe2e7fd9 Mon Sep 17 00:00:00 2001
From: Ani Sinha <anisinha@redhat.com>
Date: Thu, 5 Oct 2023 00:53:09 +0530
Subject: [PATCH] net: allow dhcp6 configuration from
 generate_fallback_configuration() (#4474)

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.

Fixes GH-4439

Signed-off-by: Ani Sinha <anisinha@redhat.com>
---
 cloudinit/net/__init__.py        |  7 ++++++-
 tests/unittests/net/test_init.py |  4 ++++
 tests/unittests/test_net.py      | 22 ++++++++++++++++++++--
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index bf21633b1fb..c0888f52702 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 561d5151d3f..60a44186efa 100644
--- a/tests/unittests/net/test_init.py
+++ b/tests/unittests/net/test_init.py
@@ -261,6 +261,7 @@ def test_generate_fallback_finds_connected_eth_with_mac(self):
                 "eth1": {
                     "match": {"macaddress": mac},
                     "dhcp4": True,
+                    "dhcp6": True,
                     "set-name": "eth1",
                 }
             },
@@ -278,6 +279,7 @@ def test_generate_fallback_finds_dormant_eth_with_mac(self):
                 "eth0": {
                     "match": {"macaddress": mac},
                     "dhcp4": True,
+                    "dhcp6": True,
                     "set-name": "eth0",
                 }
             },
@@ -293,6 +295,7 @@ def test_generate_fallback_finds_eth_by_operstate(self):
             "ethernets": {
                 "eth0": {
                     "dhcp4": True,
+                    "dhcp6": True,
                     "match": {"macaddress": mac},
                     "set-name": "eth0",
                 }
@@ -359,6 +362,7 @@ def is_netfail_master(iface, _driver=None):
             "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 3e8f721f098..fbba583c808 100644
--- a/tests/unittests/test_net.py
+++ b/tests/unittests/test_net.py
@@ -4287,6 +4287,7 @@ def test_device_driver_v2(
             "ethernets": {
                 "eth0": {
                     "dhcp4": True,
+                    "dhcp6": True,
                     "set-name": "eth0",
                     "match": {
                         "macaddress": "00:11:22:33:44:55",
@@ -4371,6 +4372,9 @@ def test_device_driver(
 
 auto eth0
 iface eth0 inet dhcp
+
+# control-alias eth0
+iface eth0 inet6 dhcp
 """
         self.assertEqual(expected.lstrip(), contents.lstrip())
 
@@ -4460,6 +4464,9 @@ def test_hv_netvsc_vf_filter(
 
 auto eth1
 iface eth1 inet dhcp
+
+# control-alias eth1
+iface eth1 inet6 dhcp
 """
         self.assertEqual(expected.lstrip(), contents.lstrip())
 
@@ -4683,7 +4690,9 @@ def test_default_generation(
 #
 BOOTPROTO=dhcp
 DEVICE=eth1000
+DHCPV6C=yes
 HWADDR=07-1c-c6-75-a4-be
+IPV6INIT=yes
 NM_CONTROLLED=no
 ONBOOT=yes
 TYPE=Ethernet
@@ -5594,7 +5603,8 @@ def test_default_generation(
             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()
@@ -5976,6 +5986,10 @@ def test_default_generation(
                 method=auto
                 may-fail=false
 
+                [ipv6]
+                method=auto
+                may-fail=false
+
                 """
                 ),
             },
@@ -6240,6 +6254,9 @@ def test_default_generation(
 
 auto eth1000
 iface eth1000 inet dhcp
+
+# control-alias eth1000
+iface eth1000 inet6 dhcp
 """
         self.assertEqual(expected.lstrip(), contents.lstrip())
 
@@ -6299,6 +6316,7 @@ class TestNetplanNetRendering:
                   ethernets:
                     eth1000:
                       dhcp4: true
+                      dhcp6: true
                       match:
                         macaddress: 07-1c-c6-75-a4-be
                       set-name: eth1000
@@ -7798,7 +7816,7 @@ def test_networkd_default_generation(
             Name=eth1000
             MACAddress=07-1c-c6-75-a4-be
             [Network]
-            DHCP=ipv4"""
+            DHCP=yes"""
         ).rstrip(" ")
 
         expected = self.create_conf_dict(expected.splitlines())