```
May 10 11:08:54 test systemd-networkd[447]: wwan0: Failed to stop LLDP: Success
May 10 11:08:54 test systemd-networkd[447]: wwan0: Gained carrier
May 10 11:08:54 test systemd-networkd[447]: wwan0: Failed to start LLDP: Success
```
The comment in udev-builtin-net_id.c (removed in grandparent commit) showed the
property without the prefix. I assume that was always the intent, because it
doesn't make much sense to concatenate anything to an arbitrary user-specified
field.
I decided to make this a separate man page because it is freakin' long.
This content could equally well go in systemd-udevd.service(8), systemd.link(5),
or a new man page for the net_id builtin.
v2:
- rename to systemd.net-naming-scheme
- add udevadm test-builtin net_id example
The latter is identical to the former, but becomes a NOP if
/var/log/journal is on the same mount as /, and thus during shutdown
unmounting /var is not necessary and hence we can keep logging until the
very end.
This adds a minimal Varlink (https://varlink.org/) implementation to our
tree. Given that we already have a JSON logic it's an easy thing to add.
Why bother?
We currently have major problems with IPC before dbus-daemon is up, and
in all components that dbus-daemon itself makes use of (such as various
NSS modules to resolve users as well as the journal which dbus-daemon
logs to). Because of that we so far ended up creating various (usually
crappy) work-arounds either coming up with secondary IPC systems or
sharing data statelessly in /run or similar. Let's clean this up, and
instead use a clean, well-defined, broker-less IPC for cases like that.
This is a minimal implementation of Varlink, i.e. the most basic logic
only. Stuff that's missing is left out on purpose: there's no
introspection/validation and there's no name service. It might make
sense to add that later, but for now let's only do the minimum buy-in we
can get away with. In particular as I'd assume that at least initially
we only use this IPC for our internal communication avoiding
introspection and the name service should be fine.
Specifically, I'd expect that we add IPC interfaces to the following
concepts with this scheme:
1. nss-resolve (so that hostname lookups with resolved work before
resolved is up)
2. journald (so that IPC calls to journald don't have to go through
dbus-daemon thus creating a cyclic dependency between journald and
dbus-daemon)
3. nss-systemd (so that dynamic user lookups via PID 1 work sanely even
inside of dbus-daemon, because otherwise we'd want to use dbus to run
dbus which causes deadlocks)
4. networkd (to make sure one can talk to it in the initrd already,
long before dbus is around)
And there might be other cases similar to this.
Certain distributions (e.g. Arch Linux) require booting with initrd, as
they lack support for commonly used filesystems in the kernel (i.e. the
support is compiled in as modules)
Evgeny Vereshchagin
Yu Watanabe
Susant Sahani
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Susant Sahani
Daniele Medri
Frantisek Sumsal