Systemd-networkd generated configuration is wrong when both ipv4 and ipv6 addresses are used

[Showfom]

We install the latest cloud-init 22.4.2-2, re-generating the new profile and the new network config file for systemd-networkd is something like

root@arch /etc/systemd/network # cat 10-cloud-init-eth0.network
[Address]
Address=192.0.2.2/24

[Address]
Address=2001:db8::2/48

[Match]
MACAddress=ea:3a:ec:46:79:8e
Name=eth0

[Network]
DHCP=no
DNS=8.8.8.8 8.8.4.4

[Route]
Gateway=192.0.2.1
Gateway=2001:db8::1

Only IPv6 is working, IPv4 is not working, there's no default route for IPv4, we need to change to

[Route]
Gateway=192.0.2.1

[Route]
Gateway=2001:db8::1

Don't know if this is a bug from cloud-init or systemd-networkd

The old bug https://bugs.launchpad.net/cloud-init/+bug/1973724?comments=all

[James Falcon (falcojr)]

Looks like cloud-init needs to specify multiple route sections as well.

https://www.freedesktop.org/software/systemd/man/systemd.network.html
"Specify several [Route] sections to configure several routes."

[James Falcon (falcojr)]

Showform, actually, it looks like this behavior has already been fixed, but is not yet released upstream. Please see https://github.com/canonical/cloud-init/pull/1868 .

[Showfom (showfom)]

James, thanks, we will wait for the next release :D

BTW, I'm Showfom, not Showform.

[Brett Holman (holmanb)]

Showfom

If you would like to test this unreleased fix, it should be possible on Arch Linux using the following patch against the 22.4.2-2 PKGBUILD. I think you'll need to build this with makepkg --skipchecksums, since this pulls directly from the tip of main.

```
diff --git a/repos/community-any/PKGBUILD b/repos/community-any/PKGBUILD
index 0c4dd72..eac1ae5 100644
--- a/repos/community-any/PKGBUILD
+++ b/repos/community-any/PKGBUILD
@@ -28,7 +28,7 @@ backup=(
   etc/cloud/cloud.cfg.d/05_logging.cfg
 )
 source=(
- $pkgname-$pkgver.tar.gz::https://github.com/canonical/cloud-init/archive/refs/tags/$pkgver.tar.gz
+ ${pkgname-$pkgver}::git+https://github.com/canonical/cloud-init.git
   $pkgname-22.1-lib_dir.patch
 )
 sha512sums=('b7d4629205ef2b184786908a3f922d635c811fed8f468649b1a892e93fbcbd54bc9eb366a49ceefb33acd32de1fc8d1a9a34c577c3b9d77825deb5f24e4fe18e'
@@ -37,18 +37,18 @@ b2sums=('9208053502f641da760dc3983838a7eddaad83ce18a8edd0f34437e3df0407a0370fcf4
         '4e03bd647ca9e1bc3d9c507824d43e4013a20d5bbcb7215755b427d0c7ded9ee48dbfb9faaae703ab2d519aee7c48a40277603c8f874347b574b7ac2b1e1a9fd')

 prepare() {
- cd $pkgname-$pkgver
+ cd $pkgname
   # we use /usr/lib
   patch -Np1 -i ../$pkgname-22.1-lib_dir.patch
 }

 build() {
- cd $pkgname-$pkgver
+ cd $pkgname
   python -m build --wheel --no-isolation
 }

 check() {
- cd $pkgname-$pkgver
+ cd $pkgname
   pytest -vv
 }

@@ -56,7 +56,7 @@ package() {
   local _file
   local site_packages=$(python -c "import site; print(site.getsitepackages()[0])")

- cd $pkgname-$pkgver
+ cd $pkgname
   python -m installer --destdir="$pkgdir" dist/*.whl
   # NOTE: due to limitations with PEP517, files are installed to site-packages,
   # not to the correct global locations (e.g. /etc and /usr), so we remove them
```

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/4067