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

[ubuntu-server-builder]

This bug was originally filed in Launchpad as LP: #2003363

Launchpad details

affected_projects = []
assignee = None
assignee_name = None
date_closed = 2023-03-23T19:37:32.652814+00:00
date_created = 2023-01-19T16:51:14.931881+00:00
date_fix_committed = 2023-01-23T15:57:20.412189+00:00
date_fix_released = 2023-03-23T19:37:32.652814+00:00
id = 2003363
importance = high
is_complete = True
lp_url = https://bugs.launchpad.net/cloud-init/+bug/2003363
milestone = None
owner = showfom
owner_name = Showfom
private = False
status = fix_released
submitter = showfom
submitter_name = Showfom
tags = []
duplicates = []

Launchpad user Showfom(showfom) wrote on 2023-01-19T16:51:14.931881+00:00

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

[ubuntu-server-builder]

Launchpad user James Falcon(falcojr) wrote on 2023-01-23T14:29:58.803764+00:00

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."

[ubuntu-server-builder]

Launchpad user James Falcon(falcojr) wrote on 2023-01-23T15:57:11.767725+00:00

Showform, actually, it looks like this behavior has already been fixed, but is not yet released upstream. Please see #1868 .

[ubuntu-server-builder]

Launchpad user Showfom(showfom) wrote on 2023-01-24T07:15:36.843116+00:00

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

BTW, I'm Showfom, not Showform.

[ubuntu-server-builder]

Launchpad user Brett Holman(holmanb) wrote on 2023-01-24T13:49:43.919905+00:00

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