Fixes#17910: we didn't clearly explain that coredumps may exist without
journal entries, and vice versa.
Also, make the examples more concrete, and use '$' instead of '#' to avoid
suggesting that running as root is required. The text is extended a bit in
various places. In the description of systemd-coredump, the details of executor
separation are split out to a separate subsection, since they are rather
detailed and not necessary to understand for normal use.
systemd.unit(5) is a wall of text. And this particular feature can be very useful
in the context of resource control. Let's avertise this cool feature a bit more.
Fixes#17900.
Before, we only allowed conditionalizing on controllers, not the hierarchy.
This commit extends this to allow a simple check for v1 (i.e. classic or hybrid),
and v2 (full unified).
An alternative approach would be to add a separate Condition for this, but I'm
not too keen on that, considering that v1 is already being deprecrecated
(c.f. 82f3063218).
This follows the addition of DEFAULT_HOSTNAME= in os-release.
The distinction between the value from os-release or the env var and
the compile-time setting is not made in the api: HostnameSource is
"default" is all cases. I think that this level of detail is not needed,
because the users of this mostly care whether the hostname was set by
user configuration or not.
The motivation is that variants of the same distro that share the same compiled
rpm want to customize various aspects of the system, in particular the
hostname. In some sense the default hostname is part of the identity of the
system, so setting it through os-release makes sense. In particular, instead of
setting a default value in /etc/hostname, the appropriate default can be baked
into the image, leaving /etc/hostname for local overrides only.
Why make this a separate field instead of e.g. using NAME from os-release?
NAME is already used for other purposes, and it seems likely that people want
to set those independently.
e3820eeaf1 did that replacement XDG_CONFIG_HOME, in one
of two places. Let's use ~/.config everywhere.
Quoting https://github.com/systemd/systemd/pull/18704#discussion_r579465254:
> I'd really drop XDG_CONFIG_HOME from the docs. It's confusing enough as it
> is. Where we don't need the indirections we should not confuse people with
> it, in particular as people might then think it's actually a good idea to use
> that env var and redirect things. I'd just show the literal path everywhere,
> even if we internally use the env var.
This is useful for various variables that modify process behaviour. This makes
it easy to set it for pid1 without touching the kernel command line. Even for
the *user manager* this also can be convenient for the unprivileged user, who
cannot modify user@.service definition.
Variables that could be set like this include $SD_EVENT_PROFILE_DELAYS,
$SYSTEMD_FALLBACK_HOSTNAME, $SYSTEMD_MEMPOOL, $SYSTMED_RDRAND, etc.
This changes the paths we read user manager config from in two ways:
- split-usr-root paths are dropped. The user manager is a poster boy for
non-early-boot, so reading dropins only from /usr is appropriate.
- we look at ~/.config/systemd/user.conf. Users should be allowed to override
their own config.
As user managers become more and more used, it becomes more important for users
to customize their own daemon. By reading from ~/.config, this is possible
without privileges.
Commit 83f72cd65f ("man,docs: document the new unit file directory for
attached images") updated the docs and man page with the new unit file
directory for attached images but included a system.attached ->
systemd.attached typo in the man page portion of the change. Fix the
typo to document the correct path.
sd_bus_get_fd() and related calls are useful for integrating a bus
connection into arbitrary event loops. But sd_bus_set_fd() is quite a
different beast, it's for using D-Bus over pre-initialized sockets or
pairs of fifos or stuff, i.e. very advanced stuff.
Let's split this man page in two, in order not to confuse things
needlessly.
And while we are at it, let's slightly extend the documentation.
