jetty.sh does not stop jetty anymore

[l-cdc]

Jetty version(s)
10.0.15

Java version/vendor (use: java -version)
openjdk version "11.0.19" 2023-04-18 LTS
OpenJDK Runtime Environment (Red_Hat-11.0.19.0.7-1.el7_9) (build 11.0.19+7-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-11.0.19.0.7-1.el7_9) (build 11.0.19+7-LTS, mixed mode, sharing)

OS type/version
Red Hat Enterprise Linux Server release 7.9 (Maipo)

Description
This bug was likely introduced by #9309 which introduces xargs to launch java. The relevant lines are

        echo ${RUN_ARGS[*]} | xargs ${JAVA} > /dev/null &
        disown $!
        echo $! > "$JETTY_PID"

$! now returns the PID of the xargs process, not the java one. Consequently, jetty.sh stop now stops xargs, but at least on my system killing xargs (version "xargs (GNU findutils) 4.5.11") does not terminate its child processes.

Note also that on systems with start-stop-daemon, this probably works as start-stop-daemon writes the child PID in the PID file if I understand the man page correctly.

The probably simplest (not best) way to fix this is to retrieve the correct PID with something like

 echo `pgrep -P $!` > "$JETTY_PID"

How to reproduce?
Issue should appear with unmodified jetty distribution on any system without start-stop-daemon.

[joakime]

Thank you for the detailed issue, and initial triage.

I think having Jetty itself produce the pid file is going to be the safest solution.

[joakime]

Opened PR #10272 - @l-cdc can you give try out that branch? see if it works for you?
Meanwhile, I'll continue testing ...

[joakime]

@l-cdc what kind of environment are you running in which doesn't have start-stop-daemon ?
I'm having a hard time finding one to test in.

[joakime]

Ah! there we go ...

$ docker run --rm -it redhat/ubi8:latest bash
Unable to find image 'redhat/ubi8:latest' locally
latest: Pulling from redhat/ubi8
0fa65fe5c23e: Pull complete 
Digest: sha256:a7143118671dfc61aca46e8ab9e488500495a3c4c73a69577ca9386564614c13
Status: Downloaded newer image for redhat/ubi8:latest
[root@79aca762789a /]# which start-stop-daemon
/usr/bin/which: no start-stop-daemon in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin)
[root@79aca762789a /]# 

[l-cdc]

@joakime I tested the branch fix/10.0.x/start-pidfile and it works for me. Many thanks for the very rapid response and PR!