No output generated in ephemeral container on Kubernetes

[Danny02]

Hi,

I have a Java application running on Kubernetes that is based on the eclipse-temurin:21-jdkimage. In my thinking I should be able to start a profiling session in a debug container (based on ubuntu:20.04 with async-profiler-3.0-linux-x64.tar.gz).

So I execute:
kubectl debug -it my-pod --image=profiling-tools --target=application

root@my-pod:/usr/local/bin# ps aux
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root           1 51.8 11.6 17839688 3764692 ?    Ssl  Mar12 542:06 java --enable-preview -cp @/app/jib-classpath-file com.my.App
root      226703  0.0  0.0   5036  4320 pts/0    Ss   08:16   0:00 /bin/bash
root      227271  0.0  0.0   5908  2912 pts/0    R+   08:17   0:00 ps aux

root@my-pod:/usr/local/bin# jps
1 App
228444 Jps

root@my-pod:/usr/local/bin# asprof -d 5 -f /tmp/profile.html 1
Profiling for 5 seconds
Done

No /tmp/profile.html file is created (even I can write to /tmp). I do not get any other console output without -f or with -L debug.

Does anyone have any idea? Missing libraries, wrong configuration, Pod security settings ....

[apangin]

-f /tmp/profile.html specifies the path inside the target container, not in the namespace where you run asprof.
Check if you can access /proc/1/root/tmp/profiler.tmp