Debugging hook scripts (snippets)

[danielb]

Hi.

I'm trying to use hook script for a VM. I've enabled the local storage to handle snippets, I put my script in /var/lib/vz/snippets/, with exec permissions, I've configured a test VM to use with

qm set 150 -hookscript local:snippets/vm_hook.pl

But it looks like it's not executed. The script is working if I execute it manually (with args 150 pre-start for example). To be sure everything is OK, I replaced my script with the sample hook found in /usr/share/pve-docs/examples/guest-example-hookscript.pl (and checkd it has exec permissions). And still, nothing in system's log (journalctl -f). So my question is : is stdout/stderr of hook scripts captured and sent to the log ? If not, what's the best way to debug ?

 

[danielb]

MMmmmhhh, in fact, stdout is captured, and can be seen in qmeventd logs (journalctl -fu qmeventd). But, only post-stop hook is fired. No trace of pre-start, post-start, pre-stop. I've simplified my script to be only

#!/usr/bin/perl -w
use strict;
use warnings;
print "GUEST HOOK: " . join(' ', @ARGV). "\n";

And, during a full start/stop of the guest, all I have is

May 15 16:16:45 pve1 qmeventd[1970]: Starting cleanup for 150
May 15 16:16:45 pve1 qmeventd[1970]: trying to acquire lock...
May 15 16:16:46 pve1 qmeventd[1970]:  OK
May 15 16:16:46 pve1 qmeventd[1970]: GUEST HOOK: 150 post-stop
May 15 16:16:46 pve1 qmeventd[1970]: Finished cleanup for 150

I'm running the latest updates from no-subscription

root@pve1:~# pveversion -v
proxmox-ve: 5.4-1 (running kernel: 4.15.18-14-pve)
pve-manager: 5.4-5 (running version: 5.4-5/c6fdb264)
pve-kernel-4.15: 5.4-2
pve-kernel-4.15.18-14-pve: 4.15.18-38
pve-kernel-4.15.18-12-pve: 4.15.18-36
pve-kernel-4.15.18-11-pve: 4.15.18-34
pve-kernel-4.15.18-10-pve: 4.15.18-32
pve-kernel-4.15.18-9-pve: 4.15.18-30
pve-kernel-4.15.18-8-pve: 4.15.18-28
pve-kernel-4.15.18-7-pve: 4.15.18-27
pve-kernel-4.15.18-5-pve: 4.15.18-24
pve-kernel-4.15.18-4-pve: 4.15.18-23
pve-kernel-4.15.18-2-pve: 4.15.18-21
pve-kernel-4.15.18-1-pve: 4.15.18-19
pve-kernel-4.15.17-3-pve: 4.15.17-14
pve-kernel-4.15.17-2-pve: 4.15.17-10
pve-kernel-4.15.17-1-pve: 4.15.17-9
pve-kernel-4.13.13-2-pve: 4.13.13-33
corosync: 2.4.4-pve1
criu: 2.11.1-1~bpo90
glusterfs-client: 3.8.8-1
ksm-control-daemon: 1.2-2
libjs-extjs: 6.0.1-2
libpve-access-control: 5.1-9
libpve-apiclient-perl: 2.0-5
libpve-common-perl: 5.0-51
libpve-guest-common-perl: 2.0-20
libpve-http-server-perl: 2.0-13
libpve-storage-perl: 5.0-42
libqb0: 1.0.3-1~bpo9
lvm2: 2.02.168-pve6
lxc-pve: 3.1.0-3
lxcfs: 3.0.3-pve1
novnc-pve: 1.0.0-3
openvswitch-switch: 2.7.0-3
proxmox-widget-toolkit: 1.0-26
pve-cluster: 5.0-37
pve-container: 2.0-37
pve-docs: 5.4-2
pve-edk2-firmware: 1.20190312-1
pve-firewall: 3.0-20
pve-firmware: 2.0-6
pve-ha-manager: 2.0-9
pve-i18n: 1.1-4
pve-libspice-server1: 0.14.1-2
pve-qemu-kvm: 3.0.1-2
pve-xtermjs: 3.12.0-1
qemu-server: 5.0-51
smartmontools: 6.5+svn4324-1
spiceterm: 3.0-5
vncterm: 1.5-3
zfsutils-linux: 0.7.13-pve1~bpo2

Any idea ?

 

[dcsapak]

the output of the pre/post-start hooks are captured in the task log of the start, not in the journal, same with the pre-stop hook

 

[danielb]

Indeed, I was only working from the cmdline and didn't even think about checking tasks logs. I'll use Sys::Syslog to have the message I'm intereted in in syslog. Thanks !