why it freeze?

[5er9e1]

I'm using Ubuntu Studio with low latency kernel (deeply merged with Debian repository packages, because I'm using Debian's repositories in main)

$ uname -a
Linux hostname 6.2.0-1017-lowlatency #17~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Nov  2 18:30:14 UTC 2 x86_64 GNU/Linux

And trying to run Postgresql container (postgres:16-alpine). And it doesn't work. It stuck beforepostgres process will be ran.

When I attach to container:

docker exec -it container_name bash

And run ps aux command, it shows me:

PID   USER     TIME  COMMAND
    1 root      4:41 su-exec postgres /usr/local/bin/docker-entrypoint.sh postgres
   16 root      0:00 bash
   22 root      0:00 ps aux

docker-entrypoint.sh stuck

When I try to run simple command like:

su-exec postgres ls

It just freezes and nothing happening until I press Ctrl+C

I have an another PC with usual Ubuntu 22.04 OS and same container and su-exec is working fine. It looks like also an environment problem so, I don't know how to reproduce it. However, it looks like that is a su-exec's bug too, because it even doesn't work being wrapped inside container. Any ideas? Should I provide some extra logs (and how to do it if yes)?

[5er9e1]

I found a problem cause. It is happening because of apparmor configuration.

After adding --security-opt apparmor=unconfined to docker compose file:

version: '3.1'

services:
  pg:
    container_name: pg
    image: postgres:16-alpine
    network_mode: bridge
    security_opt:
      - apparmor=unconfined
    environment:
      POSTGRES_PASSWORD: pass
      POSTGRES_DB: pgdb
      POSTGRES_USER: user
    volumes:
      - ./pg/data:/var/lib/postgresql/data
    ports:
      - 5432:5432

us-exec is working fine

Not sure is it should be considered as su-exec related issue or just an environment issue. If second, feel free to close the ticket