[Quadlet] Implicit network online dependencies cannot be removed

[lambinoo]

Issue Description

As explained in the quadlet man page, we should be able to remove the network-online.target implicit dependency by just overriding it with After=. But this doesn't really seem to work at all. The network-online dependencies seem to stick even by adding a After= in a [Unit] section.

In the systemd.unit man page itself, it even seems to say that you cannot reset "dependencies" (After=, Wants=) into an empty list.

Dependencies (After=, etc.) cannot be reset to an empty list, so dependencies can only be added in
drop-ins. If you want to remove dependencies, you have to override the entire unit.

Steps to reproduce the issue

Steps to reproduce the issue

1. Create a sleep.container file

   [Unit]
   After=
   Wants=
   
   [Container]
   Image=docker://docker.io/ubuntu:jammy
   Exec=sleep infinity
   

Describe the results you received

systemctl cat sleep.service will show the following:

# /run/systemd/generator/sleep.service
# Automatically generated by /usr/lib/systemd/system-generators/podman-system-generator
[Unit]
Wants=network-online.target
After=network-online.target
After=
Wants=
[...]

But looking at the effective dependencies of the unit, we can see the following:

# systemctl show sleep.service -p After -p Wants
Wants=network-online.target
After=network-online.target sysinit.target basic.target systemd-journald.socket -.mount system.slice

Describe the results you expected

That we do not see the network-online.target default dependencies added by quadlet.

podman info output

Running podman version 5.2.2 on Centos 9 stream on an amd64 machine.

Podman in a container

No

Privileged Or Rootless

Privileged

Upstream Latest Release

No

Additional environment details

Additional environment details

Additional information

Additional information like issue happens only occasionally or issue happens with a particular architecture or on a particular setting

[Luap99]

Oh, I did not expect that. I assumed you can unset them like other settings. I guess we need a special quadlet key then to unset this.

cc @ygalblum

[lambinoo]

I was under the same impression, but this was buried quite deep in the man pages.. Noticed this issue while looking at boot plots from systemd-analyze to check why everything seemed to start later than expected.

Something like QuadletDefaultDependencies= would make sense, to stay close to how systemd does things with DefaultDependencies=

[ygalblum]

I agree. @lambinoo would like to contribute this?

[lambinoo]

@ygalblum Sure, got the PR ready!