Container debugging minihint

Containers, Podman, Snippets, Virtualization 1 Minute

What’s in my container?

  1. $ podman ps --ns
CONTAINER ID  NAMES            PID    CGROUPNS  IPC         MNT         NET         PIDNS       USERNS      UTS
fe11359293e8  eloquent_austin  11090            4026532623  4026532621  4026532421  4026532624  4026531837  4026532622
  2. $ sudo ls -l /proc/11090/root/
total 22628
lrwxrwxrwx.   1 root root        7 Jul 25  2019 bin -> usr/bin
dr-xr-xr-x.   2 root root        6 Jul 25  2019 boot
drwxr-xr-x.   5 root root      360 Jan 24 12:03 dev
drwxr-xr-x.   1 root root      183 Jan 23 16:43 etc
 ...

Thank you.
[28 Jan@1135UTC] UPDATE—Actually, this doesn’t seem to work with newer systems, sorry!

Published by gbenson

I make things // he/him

Published

2 thoughts on “Container debugging minihint”

  1. Thanks for the hint.

    I have couple of rootless containers running in podman, but unable to list contents of the root directory. Any pointers? See message below:

    user@mango:~$ podman ps –ns
    CONTAINER ID NAMES PID CGROUPNS IPC MNT NET PIDNS USERNS UTS
    264e98659902 odoo10 2047 4026533069 4026533066 4026533064 4026533003 4026533067 4026532933 4026533065
    bef856e0deec database10 1984 4026533002 4026532999 4026532997 4026532936 4026533000 4026532933 4026532998
    user@mango:~$ su –
    root@mango:~# ll /proc/1984/root
    lrwxrwxrwx 1 166534 166534 0 Jan 27 17:26 /proc/1984/root -> /
    root@mango:~# ll /proc/1984/root/
    ls: cannot access ‘/proc/1984/root/’: Permission denied

  2. Hmmm, I don’t know. The sequence I posted works on RHEL7 (kernel-3.10.0-1062.4.1.el7.x86_64, podman-1.4.4-4.el7.x86_64) but not on Fedora 30 (kernel-5.4.7-100.fc30.x86_64, podman-1.7.0-3.fc30.x86_64). I’ll look into it, it has implications for the GDB.

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