--empower gives full privileges to a non-root user. Currently this
includes all capabilities but we leave the option open to add more
privileges via this option in the future.
Why is this useful? When running privileged development or debugging
commands from your home directory (think bpftrace, strace and such),
you want any files written by these tools to be owned by your current
user, and not by the root user. run0 --empower will allow you to run
all privileged operations (assuming the tools check for capabilities
and not UIDs), while any files written by the tools will still be owned
by the current user.
The DBUS_SESSION_BUS_ADDRESS and DBUS_SYSTEM_BUS_ADDRESS parameters have
an interesting syntax thats useful to complete. Let's include a
completion definition for these parameters.
--no-hostname is one of the switches I use very often. In particular,
when looking at CI logs, the hostname is almost never interesting.
-H is not yet used in journalctl, because journal operates locally, but
will want it if display of remote journals is implemented. Use -W.
The zsh completions only complete one type argument, even though multiple
args are allowed. But the same issue occurs with other completions, e.g.
for options. I don't know how to solve this.
Prefixes would be nice, but they appear to be very buggy.
A few examples:
- `udevadm test-builtin net_setup_link /sys<TAB><TAB>`: `/sysblock/`
- `udevadm test-builtin net_setup_link /sys/<TAB><TAB>`: `/sys/bin/`
- `journalctl /dev<TAB>`: `/dev//dev/`
[1] says:
> Since 0.60.0 the name argument is optional and defaults to the basename of
> the first output
We specify >= 0.62 as the supported version, so drop the duplicate name in all cases
where it is the same as outputs[0], i.e. almost all cases.
[1] https://mesonbuild.com/Reference-manual_functions.html#custom_target
This is useful when the previous invocation is unexpectedly killed.
Otherwise, if systemd-nspawn is killed forcibly, then unix-export
directory is not cleared and unmounted, and the subsequent invocation
will fail. E.g.
===
[ 18.895515] TEST-13-NSPAWN.sh[645]: + machinectl start long-running
[ 18.945703] systemd-nspawn[1387]: Mount point '/run/systemd/nspawn/unix-export/long-running' exists already, refusing.
[ 18.949236] systemd[1]: systemd-nspawn@long-running.service: Failed with result 'exit-code'.
[ 18.949743] systemd[1]: Failed to start systemd-nspawn@long-running.service.
===
This adds --json=MODE option for 'udevadm test' command.
When specified, all messages, except for the final result, will be
written to stderr, and the final result is shown in JSON format to
stdout. It may be useful for parsing the test result.
When '--resolve-names=late', systemd-udevd resolves user/group names
during each event being processed, and does not verify names on parse.
When '--resolve-names=never', systemd-udevd refuses any user/group names
on parse. Hence, the parser of udev rules behaves diffrently. Let's not
convert 'never' -> 'late' silently, and use the specified option as is.
This also updates man page and shell completion for --resolve-names
option.
systemctl has a --job-mode= argument, and adding the same argument to
systemd-run is useful for starting transient scopes with dependencies.
For example, if a transient scope BindsTo a service that is stopping,
specifying --job-mode=replace will wait for the service to stop before
starting it again, while the default job mode of "fail" will cause the
systemd-run invocation to fail.
systemctl has a --job-mode= argument, and adding the same argument to
systemd-run is useful for starting transient scopes with dependencies.
For example, if a transient scope BindsTo a service that is stopping,
specifying --job-mode=replace will wait for the service to stop before
starting it again, while the default job mode of "fail" will cause the
systemd-run invocation to fail.
This adds -D/--extra-rules-dir=DIR switch for 'udevadm test' command.
When specified, udev rules files in the specified directory will be also
loaded. This may be useful for debugging udev rules by copying some udev
rules files to a temporary directory.
This commit add the `-i` option to `udevadm trigger` that force it to
match parent devices even if they're excluded from filters.
The rationale is that some embedded devices have a huge number of
platform devices ( ~ 4k for MX8 ) they are there because they're defined
in the device tree but there isn't any action or udev rules associated
with them.
So at boot a significant time is spend triggering and processing rules
for devices that don't produce any effect and we would like to filter
them by calling:
```
udevadm trigger --type=device --action=add -s block -s tty
```
instead of the normal
```
udevadm trigger --type=device --action=add
```
so we can use filter to filter out only subsystems for we we know that
we have rules in place that do something useful.
On the other side action / rules are not triggered until the parent is
triggered ( which is part of another subsystem), so the additional option
will allows udev to complete the coldplug with only the devices we care.
Example on iMX8:
.Without the new option
```
root@dev:~# udevadm trigger --dry-run -s block --action=add -v
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0boot0
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0boot1
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p1
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p2
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p3
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p4
```
.With the new option
```
root@dev:~# udevadm trigger --dry-run -i -s block --action=add -v
/sys/devices/platform
/sys/devices/platform/bus@5b000000
/sys/devices/platform/bus@5b000000/5b010000.mmc
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0boot0
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0boot1
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p1
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p2
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p3
/sys/devices/platform/bus@5b000000/5b010000.mmc/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p4
```
Boot time reduction with this is place is ~ 1 second.
We should avoid unnecessary abbreviations for such messages, and this
puts a maximum limit on things, hence it should indicate this in the
name.
Moreover, matches is a bit confusing, since most people will probably
call "busctl monitor" without any match specification, i.e. zero
matches, but that's not what was meant here at all.
Also, add a brief switch for this (-N) since I figure in particular
"-N1" might be a frequent operation people might want to use.
Follow-up for: 989e843e75
See: #34048
