app fails to start

[Marcel Hecko]

This is very basic Ubuntu 22.04 install:

root@utest:/# dpkg -l | grep docker
ii docker.io 24.0.7-0ubuntu2~22.04.1 amd64 Linux container runtime

root@utest:/# dpkg -l | grep ctop
ii ctop 1.0.0-2.1 all Command line / text based Linux Containers monitoring tool

root@utest:/# ctop
[ERROR] Failed to locate cgroup mountpoints.

root@utest:/# mount | grep cgro
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot)

root@utest:/# ls -al /sys/fs/cgroup
total 0
dr-xr-xr-x 13 root root 0 Jul 16 14:02 .
drwxr-xr-x 10 root root 0 Jul 16 13:16 ..
-r--r--r-- 1 root root 0 Jul 16 13:16 cgroup.controllers
-rw-r--r-- 1 root root 0 Jul 16 13:16 cgroup.max.depth
-rw-r--r-- 1 root root 0 Jul 16 13:16 cgroup.max.descendants
-rw-r--r-- 1 root root 0 Jul 16 13:16 cgroup.procs
-r--r--r-- 1 root root 0 Jul 16 13:16 cgroup.stat
-rw-r--r-- 1 root root 0 Jul 16 13:16 cgroup.subtree_control
-rw-r--r-- 1 root root 0 Jul 16 13:16 cgroup.threads
-rw-r--r-- 1 root root 0 Jul 16 13:16 cpu.pressure
-r--r--r-- 1 root root 0 Jul 16 13:16 cpuset.cpus.effective
-r--r--r-- 1 root root 0 Jul 16 13:16 cpuset.mems.effective
-r--r--r-- 1 root root 0 Jul 16 13:16 cpu.stat
drwxr-xr-x 2 root root 0 Jul 16 13:16 dev-hugepages.mount
drwxr-xr-x 2 root root 0 Jul 16 13:16 dev-mqueue.mount
drwxr-xr-x 2 root root 0 Jul 16 13:16 init.scope
-rw-r--r-- 1 root root 0 Jul 16 13:16 io.cost.model
-rw-r--r-- 1 root root 0 Jul 16 13:16 io.cost.qos
-rw-r--r-- 1 root root 0 Jul 16 13:16 io.pressure
-rw-r--r-- 1 root root 0 Jul 16 13:16 io.prio.class
-r--r--r-- 1 root root 0 Jul 16 13:16 io.stat
-r--r--r-- 1 root root 0 Jul 16 13:16 memory.numa_stat
-rw-r--r-- 1 root root 0 Jul 16 13:16 memory.pressure
-r--r--r-- 1 root root 0 Jul 16 13:16 memory.stat
-r--r--r-- 1 root root 0 Jul 16 13:16 misc.capacity
drwxr-xr-x 2 root root 0 Jul 16 13:16 proc-sys-fs-binfmt_misc.mount
drwxr-xr-x 2 root root 0 Jul 16 13:16 sys-fs-fuse-connections.mount
drwxr-xr-x 2 root root 0 Jul 16 13:16 sys-kernel-config.mount
drwxr-xr-x 2 root root 0 Jul 16 13:16 sys-kernel-debug.mount
drwxr-xr-x 2 root root 0 Jul 16 13:16 sys-kernel-tracing.mount
drwxr-xr-x 2 root root 0 Jul 16 14:02 systemd
drwxr-xr-x 41 root root 0 Jul 16 14:20 system.slice
drwxr-xr-x 3 root root 0 Jul 16 13:19 user.slice