We settled on "filename" and "file system", so change a couple of places for
consistency. The exception is when there's an adjective before "file" that
binds more strongly then "name": "password file name", "output file name", etc.
Those cases are left intact.
That advice is generally apropriate for "user" programs, i.e. programs which
are run interactively and used pipelines and such. But it makes less sense for
daemons to propagate the exit signal. For example, if a process receives a SIGTERM,
it is apropriate for it to exit with 0 code. So let's just delete the whole
paragraph, since this page doesn't seem to be the right place for the longer
discussion which would be required to mention all the caveats and considerations.
Fixes#6415.
This patch adds two new special character prefixes to ExecStart= and
friends, in addition to the existing "-", "@" and "+":
"!" → much like "+", except with a much reduced effect as it only
disables the actual setresuid()/setresgid()/setgroups() calls, but
leaves all other security features on, including namespace
options. This is very useful in combination with
RuntimeDirectory= or DynamicUser= and similar option, as a user
is still allocated and used for the runtime directory, but the
actual UID/GID dropping is left to the daemon process itself.
This should make RuntimeDirectory= a lot more useful for daemons
which insist on doing their own privilege dropping.
"!!" → Similar to "!", but on systems supporting ambient caps this
becomes a NOP. This makes it relatively straightforward to write
unit files that make use of ambient capabilities to let systemd
drop all privs while retaining compatibility with systems that
lack ambient caps, where priv dropping is the left to the daemon
codes themselves.
This is an alternative approach to #6564 and related PRs.
This also alters the documentation to recommend memfds rather than /run
for serializing state across reboots. That's because /run doesn't
actually have the same lifecycle as the fd store, as it is cleared out
on restarts.
Fixes: #5606
Make sure to only apply the O_NONBLOCK flag to the fds passed via socket
activation.
Previously the flag was also applied to the fds which came from the fd store
but this was incorrect since services, after being restarted, expect that these
passed fds have their flags unchanged and can be reused as before.
The documentation was a bit unclear about this so clarify it.
The third paragraph of the Description already linked to
systemd.resource-control(5), but it was missing from the list of
additional options for the [Service] section.
The manpage claimed that ExecStop would be followed immediately by
SIGKILL, whereas the actual behavior is to go through KillMode= and
KillSignal= first.
Fixes#4490
As requested in
https://github.com/systemd/systemd/pull/4864#pullrequestreview-12372557.
docbook will substitute triple dots for the ellipsis in man output, so this has
no effect on the troff output, only on HTML, making it infinitesimally nicer.
In some places we show output from programs, which use dots, and those places
should not be changed. In some tables, the alignment would change if dots were
changed to the ellipsis which is only one character. Since docbook replaces the
ellipsis automatically, we should leave those be. This patch changes all other
places.
Our warning message was misleading, because we wouldn't "correct" anything,
we'd just ignore unkown escapes. Update the message.
Also, print just the extracted word (which contains the offending sequences) in
the message, instead of the whole line.
Fixes#4697.
This should simplify monitoring tools for services, by passing the most basic
information about service result/exit information via environment variables,
thus making it unnecessary to retrieve them explicitly via the bus.
As suggested by @mbiebl we already use the "!" special char in unit file
assignments for negation, hence we should not use it in a different context for
privileged execution. Let's use "+" instead.
Type=notify has a magic overriding case where a NotifyAccess=none
is turned into a NotifyAccess=main for sanity purposes.
This makes docs more clear about such behavior:
2787d83c28/src/core/service.c (L650):L651
This patch implements the new magic character '!'. By putting '!' in front
of a command, systemd executes it with full privileges ignoring paramters
such as User, Group, SupplementaryGroups, CapabilityBoundingSet,
AmbientCapabilities, SecureBits, SystemCallFilter, SELinuxContext,
AppArmorProfile, SmackProcessLabel, and RestrictAddressFamilies.
Fixes partially https://github.com/systemd/systemd/issues/3414
Related to https://github.com/coreos/rkt/issues/2482
Testing:
1. Create a user 'bob'
2. Create the unit file /etc/systemd/system/exec-perm.service
(You can use the example below)
3. sudo systemctl start ext-perm.service
4. Verify that the commands starting with '!' were not executed as bob,
4.1 Looking to the output of ls -l /tmp/exec-perm
4.2 Each file contains the result of the id command.
`````````````````````````````````````````````````````````````````
[Unit]
Description=ext-perm
[Service]
Type=oneshot
TimeoutStartSec=0
User=bob
ExecStartPre=!/usr/bin/sh -c "/usr/bin/rm /tmp/exec-perm*" ;
/usr/bin/sh -c "/usr/bin/id > /tmp/exec-perm-start-pre"
ExecStart=/usr/bin/sh -c "/usr/bin/id > /tmp/exec-perm-start" ;
!/usr/bin/sh -c "/usr/bin/id > /tmp/exec-perm-star-2"
ExecStartPost=/usr/bin/sh -c "/usr/bin/id > /tmp/exec-perm-start-post"
ExecReload=/usr/bin/sh -c "/usr/bin/id > /tmp/exec-perm-reload"
ExecStop=!/usr/bin/sh -c "/usr/bin/id > /tmp/exec-perm-stop"
ExecStopPost=/usr/bin/sh -c "/usr/bin/id > /tmp/exec-perm-stop-post"
[Install]
WantedBy=multi-user.target]
`````````````````````````````````````````````````````````````````
This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section
into the [Unit] section of unit files, and thus support it in all unit types, not just in services.
This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that
repeated start-up failure due to failed conditions is also considered for the start limit logic.
For compatibility the four options may also be configured in the [Service] section still, but we only document them in
their new section [Unit].
This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express
more clearly what it is about, after all it's only triggered through the start limit being hit.
Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike.
Fixes: #2467
This makes sure we never run two control processes at the same time, we cannot keep track off.
This introduces a slight change of behaviour but cleans up the definition of ExecStop= and ExecStopPost=. The former is
now invoked only if the service managed to start-up correctly. The latter is called even if start-up failed half-way.
Thus, ExecStopPost= may be used as clean-up step for both successful and failed start-up attempts, but ExecStop='s
purpose is clearly defined as being responsible for shutting down the service and nothing else.
The precise behaviour of this was not documented yet. This commit adds the necessary docs.
Fixes: #1254
This completes the set of man pages for sd-event and contains some minor
other fixes for other man pages too.
The sd_event_set_name(3) man page is renamed to
sd_event_source_set_description(3), which is the correct name of the
concept today.
For all units ensure there's an "Automatic Dependencies" section in the
man page, and explain which dependencies are automatically added in all
cases, and which ones are added on top if DefaultDependencies=yes is
set.
This is also done for systemd.exec(5), systemd.resource-control(5) and
systemd.unit(5) as these pages describe common behaviour of various unit
types.
