Compared to PID1 where systemd-oomd has to be the client to PID1
because PID1 is a more privileged process than systemd-oomd, systemd-oomd
is the more privileged process compared to a user manager so we have
user managers be the client whereas systemd-oomd is now the server.
The same varlink protocol is used between user managers and systemd-oomd
to deliver ManagedOOM property updates. systemd-oomd now sets up a varlink
server that user managers connect to to send ManagedOOM property updates.
We also add extra validation to make sure that non-root senders don't
send updates for cgroups they don't own.
The integration test was extended to repeat the chill/bloat test using
a user manager instead of PID1.
Unfortunately, when checking the return/exit code using &&, ||, if,
while, etc., `set -e` is disabled for all nested functions as well,
which leads to incorrectly ignored errors, *sigh*.
Example:
```
set -eu
set -o pipefail
task() {
echo "task init"
echo "this should fail"
false
nonexistentcommand
echo "task end (we shouldn't be here)"
}
if ! task; then
echo >&2 "The task failed"
exit 1
else
echo "The task passed"
fi
```
```
$ bash test.sh
task init
this should fail
test.sh: line 10: nonexistentcommand: command not found
task end (we shouldn't be here)
The task passed
$ echo $?
0
```
But without the `if`, everything works "as expected":
```
set -eu
set -o pipefail
task() {
echo "task init"
echo "this should fail"
false
nonexistentcommand
echo "task end (we shouldn't be here)"
}
task
```
```
$ bash test.sh
task init
this should fail
$ echo $?
1
```
Wonderful.
Pressure remains > 1% after a kill for some time and could cause
testchill to get killed. Bumping the limit from 1% to 20% should help
with this.
Fixes#20118
The `dracut_install` is a misnomer, since the systemd integration test
suite is based on the original dracut's test suite, and not all the
references to dracut has been edited out. Let's fix that.
For most fields, the text shown by `.id` is the value that should be set
in the unit file; however, for RestrictNamespaces, it is not. Changing
this to show the actual text makes it more clear to a user what the
actual change that needs to be made to the unit file is.
