netplan.io postinst script creates entries in /run/systemd/system

[Pavel Zakharov]

The bug affects version 0.106.1-7ubuntu0.22.04.3 on jammy. Version 0.106.1-7ubuntu0.22.04.2 is not affected.

netplan.io postinst script runs /usr/libexec/netplan/generate, which creates directory /run/systemd/system and some files in it:

```
# ls -R /run/systemd/system
/run/systemd/system:
netplan-ovs-cleanup.service systemd-networkd.service.wants

/run/systemd/system/systemd-networkd.service.wants:
netplan-ovs-cleanup.service
```

The problem is that netplan creates those files even on a system that is not booted, such as in a chroot when building a new OS with the netplan.io package. The immediate impact is that lots of other programs / scripts, check for the existence of /run/systemd/system to determine if systemd is running, and thus if it does exist then they attempt to run systemd commands.

In some cases this causes failures, which fail the entire build.

The right behaviour for netplan.io's generate command should be to check for the existence of directory /run/systemd/system before creating anything in there.

[Danilo Egea Gondolfo (danilogondolfo)]

Hi, thanks for your bug report.

We are already of this issue and working on a fix.

Please refer to this bug https://bugs.launchpad.net/ubuntu/+source/netplan.io/+bug/2071333