This option is likely to be very useful for systemd-run invocations,
hence let's add a shortcut for it.
With this new concepts it's now very easy to put together systemd-run
invocations that leave zero artifacts in the system, including when they
fail.
Right now, the option only takes one of two possible values "inactive"
or "inactive-or-failed", the former being the default, and exposing same
behaviour as the status quo ante. If set to "inactive-or-failed" units
may be collected by the GC logic when in the "failed" state too.
This logic should be a nicer alternative to using the "-" modifier for
ExecStart= and friends, as the exit data is collected and logged about
and only removed when the GC comes along. This should be useful in
particular for per-connection socket-activated services, as well as
"systemd-run" command lines that shall leave no artifacts in the
system.
I was thinking about whether to expose this as a boolean, but opted for
an enum instead, as I have the suspicion other tweaks like this might be
a added later on, in which case we extend this setting instead of having
to add yet another one.
Also, let's add some documentation for the GC logic.
When preparing for a restart we quickly go through the DEAD/INACTIVE
service state before entering AUTO_RESTART. When doing this, we need to
make sure we don't destroy the FD store. Previously this was done by
checking the failure state of the unit, and keeping the FD store around
when the unit failed, under the assumption that the restart logic will
then get into action.
This is not entirely correct howver, as there might be failure states
that will no result in restarts.
With this commit we slightly alter the logic: a ref counter for the fd
store is added, that is increased right before we handle the restart
logic, and decreased again right-after.
This should ensure that the fdstore lives exactly as long as it needs.
Follow-up for f0bfbfac43.
And let's make use of it to implement two new unit settings with it:
1. LogLevelMax= is a new per-unit setting that may be used to configure
log priority filtering: set it to LogLevelMax=notice and only
messages of level "notice" and lower (i.e. more important) will be
processed, all others are dropped.
2. LogExtraFields= is a new per-unit setting for configuring per-unit
journal fields, that are implicitly included in every log record
generated by the unit's processes. It takes field/value pairs in the
form of FOO=BAR.
Also, related to this, one exisiting unit setting is ported to this new
facility:
3. The invocation ID is now pulled from /run/systemd/units/ instead of
cgroupfs xattrs. This substantially relaxes requirements of systemd
on the kernel version and the privileges it runs with (specifically,
cgroupfs xattrs are not available in containers, since they are
stored in kernel memory, and hence are unsafe to permit to lesser
privileged code).
/run/systemd/units/ is a new directory, which contains a number of files
and symlinks encoding the above information. PID 1 creates and manages
these files, and journald reads them from there.
Note that this is supposed to be a direct path between PID 1 and the
journal only, due to the special runtime environment the journal runs
in. Normally, today we shouldn't introduce new interfaces that (mis-)use
a file system as IPC framework, and instead just an IPC system, but this
is very hard to do between the journal and PID 1, as long as the IPC
system is a subject PID 1 manages, and itself a client to the journal.
This patch cleans up a couple of types used in journal code:
specifically we switch to size_t for a couple of memory-sizing values,
as size_t is the right choice for everything that is memory.
Fixes: #4089Fixes: #3041Fixes: #4441
Let's clarify that these settings only apply to stdout/stderr logging.
Always mention the journal before syslog (as the latter is in most ways
just a legacy alias these days). Always mention the +console cases too.
When we drop messages of a unit, we log about. Let's add some structured
data to that. Let's include how many messages we dropped, but more
importantly, let's link up the message we generate to the unit we
dropped the messages from by using the "OBJECT" logic, i.e. by
generating OBJECT_SYSTEMD_UNIT= fields and suchlike, that "journalctl
-u" and friends already look for.
Fixes: #6494
In chroot environments, /etc might not be fully initialized: /etc/machine-id
can be missing for example. This makes the expansions of affected specifiers
impossible at that time.
These cases should not be considered as errors and such failures shouldn't be
logged at an error level therefore this patch downgrades the level used to
LOG_NOTICE in such cases.
Also this is logged at LOG_NOTICE only the first time and then downgrade to
LOG_DEBUG for the rest. That way, if debugging is enabled we get the full
output, but otherwise we only see only one message.
The expansion of specifiers is now self contained in a dedicated function
instead of being spread all over the place.
Implement DHCPv6 option to exchange information about the Fully
Qualified Domain Name (FQDN) according to RFC 4704.
The RFC 4704 describes two models of operations in section 3,
currently only the second model is supported (DHCPv6 server
updates both the AAAA and the PTR RRs).
The existing DHCP Section Options SendHostname and Hostname are
sent as FQDN to the server. According to section 4.2 sending
only parts of its FQDN is allowed.
Fixes#4682.
Technically DNS allows any ASCII character to be used in the
domain name. Also the DHCP specification for the FQDN option
(RFC 4702) does not put restriction on labels.
However, hostnames do have stricter requirements and typically
should only use characters from a-z (case insensitve), 0-9 and
minus.
Currently we require hostname/FQDN to be either a hostname or
a valid DNS name. Since dns_name_is_valid() allows any ASCII
characters this allows to specify hostnames which are typically
not valid.
Check hostname/FQDN more strictly and require them to pass both
tests. Specifically this requires the entire FQDN to be below 63.
This addition is kept brief on purpose, since in order to write a good
generator users don't really need to grok templating/instantiation.
Fixes: #7257
We would continue, but still return an error at the end. This isn't useful
because we'd still error-out in main().
Also, add a missing error message when we fail to mkdir.
This was probably a typo, since depending proxy-to-nginx.service on
itself makes no sense, but depending on the socket does.
Signed-off-by: Roland Hieber <r.hieber@pengutronix.de>
It is possible that kernel will reject our netlink message that
configures the link. However, we should always make sure that interface
will be named properly otherwise we can leave interfaces having
unpredictable kernel names. Thus we don't return early and continue to
export name and link file properties.
Suggested-by: Tom Gundersen <teg@jklm.no>
SetLinger is authorized by the PolicyKit action "set-self-linger", if it is
not passed an explicit UID.
According to comments we were determining the default UID from the client's
session. However, user processes e.g. which are run from a terminal
emulator do not necessarily belong to a session scope unit. They may
equally be started from the systemd user manager [1][2]. Actually the
comment was wrong, and it would also have worked for processes
started from the systemd user manager.
Nevertheless it seems to involve fetching "augmented credentials" i.e.
it's using a racy method, so we shouldn't have been authenticating based
on it.
We could change the default UID, but that raises issues especially for
consistency between the methods. Instead we can just use the clients
effective UID for authorization.
This commit also fixes `loginctl enable-linger $USER` to match the docs
that say it was equivalent to `loginctl enable-linger` (given that $USER
matches the callers user and owner_uid). Previously, the former would not
have suceeded for unpriviliged users in the default configuration.
[1] It seems the main meaning of per-session scopes is tracking the PAM
login process. Killing that provokes logind to revoke device access. Less
circularly, killing it provokes getty to hangup the TTY.
[2] User units may be started with an environment which includes
XDG_SESSION_ID (presuambly GNOME does this?). Or not.
To maintain consistency with `loginctl user-status`, drop the fallback to
XDG_SESSION_ID for `loginctl enable-linger`. The fallback was unnecessary
and also incorrect: it passed the numeric value of the session identifier
as a UID value.
The manpages tell that such calls have quite limited meaning. logind has
a few in the implementation of what remains of the session concept.
At the same time, logind basically exposes sd_pid_get_session() as public
API. This is absolutely required, to retain compatability e.g. with Xorg.
But client code will work in more situations if it avoids assuming that it
runs in a session itself.
Its use inside the login session could be replaced with $XDG_SESSION_ID
(which pam_systemd sets). I don't know whether it would be useful to
change Xorg at this point or not. But if you were building something new,
you would think about whether you want to support running it in a systemd
service.
Comment these logind API features, acknowledging the reason they exist is
based in history. I.e. help readers avoid drawing implications from their
existence which apply to history, but not the current general case.
Finally, searching these revealed a call to sd_pid_get_session() in
implementing some types of logind inhibitors. So these inhibitors don't
work as intended when taken from inside a systemd user service :(. Comment
this as well, deferring it as ticket #6852.
If you try to run `loginctl user-status` on a non-logged in user to see
whether "Linger" is enabled, it doesn't work.
If you're already an expert in logind, the fact that the user is considered
unknown actually tells you the user is not lingering. So, probably they
they do not have lingering enabled. I think we can point towards this
without being misleading.
I also reword it because I thought it was slightly confusing to run
`loginctl user-status root` and get an error back about "User 0". Try to
be more specific, that it is "User ID 0".
It's confusing that the bus API has aliases like "session/self" that return
an error based on ENXIO, when it also has methods that return e.g.
NO_SESSION_FOR_PID for the same problem. The latter kind of error includes
more specifically helpful messages.
"user/self" is the odd one out; it returns a generic UnknownObject error
when it is not applicable to the caller. It's not clear whether this was
intentional, but at first I thought it was more correct. More
specifically, user_object_find() was returning 0 for "user/self", in the
same situations (more or less) where user_node_enumerator() was omitting
"user/self". I thought that was a good idea, because returning e.g. -ENXIO instead
suggested that there _is_ something specific on that path. And it could be
confused with errors of the method being called.
Therefore I suggested changing the enumerator, always admitting that there
is a handler for the path "foo/self", but returning a specific error when
queried. However this interacts poorly with tools like D-Feet or `busctl`.
In either tool, looking at logind would show an error message, and then go
on to omit "user/self" in the normal listing. These tools are very useful,
so we don't want to interfere with them.
I think we can change the error codes without causing problems. The self
objects were not listed in the documentation. They have been suggested to
other projects - but without reference to error reporting. "seat/self" is
used by various Wayland compositors for VT switching, but they don't appear
to reference specific errors.
We _could_ insist on the link between enumeration and UnknownObject, and
standardize on that as the error for the aliases. But I'm not aware of any
practical complaints, that we returned an error from an object that didn't
exist.
Instead, let's unify the codepaths for "user/self" vs GetUserByPid(0) etc.
We will return the most helpful error message we can think of, if the
object does not exist. E.g. for "session/self", we might return an error
that the caller does not belong to a session. If one of the compositors is
ever simplified to use "session/self" in initialization, users would be
able to trigger such errors (e.g. run `gnome-shell` inside gnome-terminal).
The message text will most likely be logged. The user might not know what
the "session" is, but at least we'll be pointing towards the right
questions. I think it should also be clearer for development / debugging.
Unifying the code paths is also slightly helpful for auditing / marking
calls to sd_bus_creds_get_session() in subsequent commits.
GetSessionByPID(0) can fail with NO_SESSION_FOR_PID. More obscurely, if
the session is abandoned, it can return NO_SUCH_SESSION. It is not clear
that the latter was intended. The message associated with the former,
hints that this was overlooked.
We don't have a document enumerating the errors. Any specific
error-handling in client code, e.g. translated messages, would also be
liable to overlook the more obscure error code.
I can't see any equivalent condition for GetUserByPID(0). On the other
hand, the code did not return NO_USER_FOR_PID where it probably should.
The relevant code is right next to that for GetSessionByPID(0), so it will
be simpler to understand if both follow the same pattern.
PR #7186 changes requires_mounts_for from strv to Hashmap.
So, it is necessary to implement a function for getting the property RequiresMountsFor=.
This introduces property_get_requires_mounts_for() which reads the Hashmap
and sends messages to bus.
Fixes#7321.
If you use machinectl to bind a file into a container, it responds with a confusing error message about a temporary directory not being a directory.
I just swapped it to error with the source that was passed, rather than the tmpdir.
It would also be nice to be able to bind files, but that's a separate issue (#7195).
Before the change:
root@epona /var/lib/sandbox $ cat bar/foo
Hello world!
root@epona /var/lib/sandbox $ machinectl bind testing /var/lib/sandbox/bar/foo /foo
Failed to bind mount: Failed to overmount /tmp/propagate.W5TNsj/mount: Not a directory
After the change:
root@epona /var/lib/sandbox $ machinectl bind testing /var/lib/sandbox/bar/foo /foo
Failed to bind mount: Failed to overmount /var/lib/sandbox/bar/foo: Not a directory
