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users/services: s6: fix so `s6-rc stop` can actually kill processes

This commit is contained in:
Colin 2024-03-24 11:48:41 +00:00
parent 774066e53c
commit e62be121e2
1 changed files with 31 additions and 5 deletions
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36
modules/users/s6-rc.nix
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@ -60,7 +60,7 @@ let
logger = serviceToFs' {
name = "logger:${name}";
consumerFor = name;
run = ''exec s6-log -- T p'${name}:' "${logBase}/${name}"'';
run = ''s6-log -- T p'${name}:' "${logBase}/${name}"'';
type = "longrun";
};
in (serviceToFs' {
@ -91,7 +91,7 @@ let
"data".dir = {
"check".executable = maybe (check != null) ''
#!/bin/sh
exec ${check}
${check}
'';
};
# N.B.: if this service is a bundle, then dependencies.d is ignored
@ -101,14 +101,40 @@ let
;
"finish".executable = maybe (finish != null) ''
#!/bin/sh
exec ${finish}
${finish}
'';
"notification-fd".text = maybe (check != null) "3";
"producer-for".text = maybe (producerFor != null) producerFor;
"run".executable = maybe (run != null) ''
#!/bin/sh
echo "starting: s6-${name}"
exec ${maybe-notify}${run} 2>&1
log() {
printf 's6[%s]: %s\n' '${name}' "$1" | tee /dev/stderr
}
log "preparing"
# s6 is too gentle when i ask it to stop a service,
# so explicitly kill children on exit.
# see: <https://stackoverflow.com/a/2173421>
# before changing this, test that the new version actually kills a service with `s6-rc down <svcname>`
down() {
log "trapped on abort signal"
# "trap -": to avoid recursing
trap - SIGINT SIGQUIT SIGTERM
log "killing process group"
# "kill 0" means kill the current process group (i.e. all descendants)
kill 0
exit 0
}
trap down SIGINT SIGQUIT SIGTERM
log "starting"
# run the service from $HOME by default.
# particularly, this impacts things like "what directory does my terminal open in".
# N.B. do not run the notifier from $HOME, else it won't know where to find the `data/check` program.
# N.B. must be run with `&` + `wait`, else we lose the ability to `trap`.
${maybe-notify}env --chdir="$HOME" ${run} <&0 &
wait
log "exiting"
'';
};
};