This commit introduces new D-Bus API, StartAuxiliaryScope(). It may be
used by services as part of the restart procedure. Service sends an
array of PID file descriptors corresponding to processes that are part
of the service and must continue running also after service restarts,
i.e. they haven't finished the job why they were spawned in the first
place (e.g. long running video transcoding job). Systemd creates new
scope unit for these processes and migrates them into it. Cgroup
properties of scope are copied from the service so it retains same
cgroup settings and limits as service had.
Users become perplexed when they run their workload in a unit with no
explicit limits configured (moreover, listing the limit property would
even show it's infinity) but they experience unexpected resource
limitation.
The memory and pid limits come as the most visible, therefore add new
unit read-only properties:
- EffectiveMemoryMax=,
- EffectiveMemoryHigh=,
- EffectiveTasksMax=.
These properties represent the most stringent limit systemd is aware of
for the given unit -- and that is typically(*) the effective value.
Implement the properties by simply traversing all parents in the
leaf-slice tree and picking the minimum value. Note that effective
limits are thus defined even for units that don't enable explicit
accounting (because of the hierarchy).
(*) The evasive case is when systemd runs in a cgroupns and cannot
reason about outer setup. Complete solution would need kernel support.
This is the equivalent of RequiresMountsFor=, but adds Wants= instead
of Requires=. It will be useful for example for the autogenerated
systemd-cryptsetup units.
Fixes https://github.com/systemd/systemd/issues/11646
In systemctl-show we only show current swap if ever swapped or non-zero. This
reduces the noise on swapless systems, that would otherwise always show a swap
value that never has the chance to become non-zero. It further reduces the
noise for services that never swapped.
Linux's Control Group v2 interfaces exposes memory.peak, which contains the
"max memory usage recorded for the cgroup and its descendants since the
creation of the cgroup."
This commit adds a new property "MemoryPeak" for units and makes "systemctl
show" display this value if it is available.
Fixes#29878.
Signed-off-by: Florian Schmaus <flo@geekplace.eu>
Instead of mounting over, do an atomic swap using mount beneath, if
available. This way assets can be mounted again and again (e.g.:
updates) without leaking mounts.
Before this commit, $USER, $HOME, $LOGNAME and $SHELL are only
set when User= is set for the unit. For system service, this
results in different behaviors depending on whether User=root is set.
$USER always makes sense on its own, so let's set it unconditionally.
Ideally $HOME should be set too, but it causes trouble when e.g. getty
passes '-p' to login(1), which then doesn't override $HOME. $LOGNAME and
$SHELL are more like "login environments", and are generally not
suitable for system services. Therefore, a new option SetLoginEnvironment=
is also added to control the latter three variables.
Fixes#23438
Replaces #8227
Add a new boolean for units, SurviveFinalKillSignal=yes/no. Units that
set it will not have their process receive the final sigterm/sigkill in
the shutdown phase.
This is implemented by checking if a process is part of a cgroup marked
with a user.survive_final_kill_signal xattr (or a trusted xattr if we
can't set a user one, which were added only in kernel v5.7 and are not
supported in CentOS 8).
New directive `NFTSet=` provides a method for integrating dynamic cgroup IDs
into firewall rules with NFT sets. The benefit of using this setting is to be
able to use control group as a selector in firewall rules easily and this in
turn allows more fine grained filtering. Also, NFT rules for cgroup matching
use numeric cgroup IDs, which change every time a service is restarted, making
them hard to use in systemd environment.
This option expects a whitespace separated list of NFT set definitions. Each
definition consists of a colon-separated tuple of source type (only "cgroup"),
NFT address family (one of "arp", "bridge", "inet", "ip", "ip6", or "netdev"),
table name and set name. The names of tables and sets must conform to lexical
restrictions of NFT table names. The type of the element used in the NFT filter
must be "cgroupsv2". When a control group for a unit is realized, the cgroup ID
will be appended to the NFT sets and it will be be removed when the control
group is removed. systemd only inserts elements to (or removes from) the sets,
so the related NFT rules, tables and sets must be prepared elsewhere in
advance. Failures to manage the sets will be ignored.
If the firewall rules are reinstalled so that the contents of NFT sets are
destroyed, command systemctl daemon-reload can be used to refill the sets.
Example:
```
table inet filter {
...
set timesyncd {
type cgroupsv2
}
chain ntp_output {
socket cgroupv2 != @timesyncd counter drop
accept
}
...
}
```
/etc/systemd/system/systemd-timesyncd.service.d/override.conf
```
[Service]
NFTSet=cgroup:inet:filter:timesyncd
```
```
$ sudo nft list set inet filter timesyncd
table inet filter {
set timesyncd {
type cgroupsv2
elements = { "system.slice/systemd-timesyncd.service" }
}
}
```
This adds a new "PollLimit" pair of settings to .socket units, very
similar to existing "TriggerLimit" logic. The differences are:
* PollLimit focusses on the polling on the sockets, and pauses that
temporarily if a ratelimit on that is reached. TriggerLimit otoh
focusses on the triggering effect of socket units, and stops
triggering once the ratelimit is hit.
* While the trigger limit being hit is an action that causes the socket
unit to fail the polling limit being reached will just temporarily
disable polling on the socket fd, and it is resumed once the ratelimit
interval is over.
* When a socket unit operates on multiple socket fds (e,g, ListenStream=
on both some ipv6 and an ipv4 address or so). Then the PollLimit will
be specific to each fd, while the trigger limit is specific to the
whole unit.
Implementation-wise this is mostly a wrapper around sd-event's
sd_event_source_set_ratelimit(), which exposes the desired behaviour
directly.
Usecase for all of this: socket services which when overloaded with
connections should just slow down reception of it, but not fail
persistently.
This tries to add information about when each option was added. It goes
back to version 183.
The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.
As it says on the tin, configures the unit to survive a soft reboot.
Currently all the following options have to be set by hand:
Conflicts=reboot.target kexec.target poweroff.target halt.target
Before=reboot.target kexec.target poweroff.target halt.target
After=sysinit.target basic.target
DefaultDependencies=no
IgnoreOnIsolate=yes
This is not very user friendly. If new default dependencies are added,
or new shutdown/reboot types, they also have to be added manually.
The new option is much simpler, easy to find, and does the right thing
by default.
When this option is set to direct, the service restarts without entering a failed
state. Dependent units are not notified of transitory failure.
This is useful for the following use case:
We have a target with Requires=my-service, After=my-service.
my-service.service is a oneshot service and has Restart=on-failure in
its definition.
my-service.service can get stuck for various reasons and time out, in
which case it is restarted. Currently, when it fails the first time, the
target fails, even though my-service is restarted.
The behavior we're looking for is that until my-service is not restarted
anymore, the target stays pending waiting for my-service.service to
start successfully or fail without being restarted anymore.
This property reports whether the system is running inside a confidential
virtual machine.
Related: https://github.com/systemd/systemd/issues/27604
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This setting allows services to run in an ephemeral copy of the root
directory or root image. To make sure the ephemeral copies are always
cleaned up, we add a tmpfiles snippet to unconditionally clean up
/var/lib/systemd/ephemeral. To prevent in use ephemeral copies from
being cleaned up by tmpfiles, we use the newly added COPY_LOCK_BSD
and BTRFS_SNAPSHOT_LOCK_BSD flags to take a BSD lock on the ephemeral
copies which instruct tmpfiles to not touch those ephemeral copies as
long as the BSD lock is held.
Doesn't really matter since the two unicode symbols are supposedly
equivalent, but let's better follow the unicode recommendations to
prefer greek small letter mu, as per:
https://www.unicode.org/reports/tr25
ImportCredential= takes a credential name and searches for a matching
credential in all the credential stores we know about it. It supports
globs which are expanded so that all matching credentials are loaded.
This adds support for KSM (kernel samepage merging). It adds a new
boolean parameter called MemoryKSM to enable the feature. The feature
can only be enabled with newer kernels.
Dump*() methods can take quite some time due to the amount of data to
serialize, so they can potentially stall the manager. Make them
privileged, as they are debugging tools anyway. Use a new 'dump'
capability for polkit, and the 'reload' capability for SELinux, as
that's also non-destructive but slow.
If the caller is not privileged, allow it but rate limited to 10 calls
every 10 minutes.
This implements a minimal subset of #24961, but in a lot more
restrictive way: we only allow one level of subcgroup (as that's enough
to address the no-processes in inner cgroups rule), and does not change
anything about threaded cgroup logic or similar, or make any of this new
behaviour mandatory.
All this does is this: all non-control processes we invoke for a unit
we'll invoke in a subgroup by the specified name.
We'll later port all our current services that use cgroup delegation
over to this, i.e. user@.service, systemd-nspawn@.service and
systemd-udevd.service.
Oftentimes it is useful to allow the per-service fd store to survive
longer than for a restart. This is useful in various scenarios:
1. An fd to some security relevant object needs to be stashed somewhere,
that should not be cleaned automatically, because the security
enforcement would be dropped then.
2. A user namespace fd should be allocated on first invocation and be
kept around until the user logs out (i.e. systemd --user ends), á la
#16328 (This does not implement what #16318 asks for, but should
solve the use-case discussed there.)
3. There's interest in allow a concept of "userspace reboots" where the
kernel stays running, and userspace is swapped out (i.e. all services
exit, and the rootfs transitioned into a new version of it) while
keeping some select resources pinned, very similar to how we
implement a switch root. Thus it is useful to allow services to exit,
while leaving their fds around till the very end.
This is exposed through a new FileDescriptorStorePreserve= setting that
is closely modelled after RuntimeDirectoryPreserve= (in fact it reused
the same internal type), since we want similar behaviour in the end, and
quite often they probably want to be used together.
This is a followup to
413e8650b7
> tree-wide: Use "unmet" for condition checks, not "failed"
Since I noticed when running `systemctl status` on a recent
systemd still seeing
`Condition: start condition failed`
To recap the original rationale here for "unmet" is that it's
normal for some units to be conditional, so the term "failure"
here is too strong.
Follow-up for #26902 and #26971
Let's always calculate the next restart interval
since that's more useful.
For that, we add 1 to s->n_restarts unconditionally,
and change RestartUSecCurrent property to RestartUSecNext.
interval between restarts
RestartSteps= accepts a positive integer as the number of steps
to take to increase the interval between auto-restarts from
RestartSec= to RestartSecMax=, or 0 to disable it.
Closes#6129
