Ramon, thank you for the detailed test case, I was able to run through it exactly as you described, both as root user (see attached) and as nagios (with sudo setup). I suspect I'm unable to reproduce the issue you're seeing since under lxc the /sys/kernel/debug directory belongs to the host and thus is owned by nobody:nogroup, (although I should think that it would produce a permission denied error.)
>From the host: # mount | grep tracing tracefs on /sys/kernel/debug/tracing type tracefs (rw,relatime) In any case, regarding the bug itself, I am able to detect the permissions error: # /usr/lib/nagios/plugins/check_disk -e DISK CRITICAL - /sys/kernel/debug/tracing is not accessible: Permission denied # ls -la /sys/kernel/debug/tracing ls: cannot access '/sys/kernel/debug/tracing': Permission denied # /usr/lib/nagios/plugins/check_disk -e -X tracefs DISK OK| /=44420MB;;;0;3754403 /dev=0MB;;;0;0 /dev/full=0MB;;;0;16018 /dev/null=0MB;;;0;16018 /dev/random=0MB;;;0;16018 /dev/tty=0MB;;;0;16018 /dev/urandom=0MB;;;0;16018 /dev/zero=0MB;;;0;16018 /dev/fuse=0MB;;;0;16018 /dev/net/tun=0MB;;;0;16018 /dev/lxd=0MB;;;0;0 /dev/.lxd-mounts=0MB;;;0;0 /dev/shm=0MB;;;0;16041 /run=16MB;;;0;16041 /run/lock=0MB;;;0;5 /sys/fs/cgroup=0MB;;;0;16041 /var/lib/lxd/shmounts=0MB;;;0;0 /var/lib/lxd/devlxd=0MB;;;0;0 /run/user/1001=0MB;;;0;3208 The suggestion in comment #16 looks like the best approach for addressing the issue so far. Alternatively, I posted a patch to LP #1827159 for altering check_disk itself, however as mentioned in comment #9 on this bug, excluding all tmpfs would be too broad. Ramon, if you can test out the approach outlined in comment #16 and let me know if it seems suitable for your use case, perhaps we should proceed with implementing an SRU for that. ** Attachment added: "Screenshot from 2019-07-17 14-19-10.png" https://bugs.launchpad.net/ubuntu/+source/nagios-plugins/+bug/1516451/+attachment/5277690/+files/Screenshot%20from%202019-07-17%2014-19-10.png -- You received this bug notification because you are a member of AIMS, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1516451 Title: check_disk plugin broken after upgrade to 15.10 Status in nagios-plugins package in Ubuntu: Incomplete Bug description: I didn't touch my Nagios config, just update my system from 15.04 to 15.10. Suddenly the default localhost/Disk Space check fails with the following output: DISK CRITICAL - /sys/kernel/debug/tracing is not accessible: Permission denied This can be reproduced when manually running the underlying command as user "nagios": $ /usr/lib/nagios/plugins/check_disk -w '20%' -c '10%' -e DISK CRITICAL - /sys/kernel/debug/tracing is not accessible: Permission denied When I run it as root it works: # /usr/lib/nagios/plugins/check_disk -w '20%' -c '10%' -e DISK OK| /dev=0MB;1186;1334;0;1483 /run=8MB;239;269;0;299 /=17157MB;57386;64559;0;71733 /dev/shm=0MB;1199;1349;0;1499 /run/lock=0MB;4;4;0;5 /sys/fs/cgroup=0MB;1199;1349;0;1499 /boot=48MB;181;204;0;227 /run/user/0=0MB;239;269;0;299 Seems "nagios" user can't access the dir it tries to access: # ls -la /sys/kernel/debug/tracing drwx------ 7 root root 0 Nov 15 19:40 . # lsb_release -rd Description: Ubuntu 15.10 Release: 15.10 # apt-cache policy nagios-plugins-basic nagios-plugins-basic: Installed: 1.5-3ubuntu1 Candidate: 1.5-3ubuntu1 Version table: *** 1.5-3ubuntu1 0 500 http://de.archive.ubuntu.com/ubuntu/ wily/main amd64 Packages 100 /var/lib/dpkg/status To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nagios-plugins/+bug/1516451/+subscriptions -- Mailing list: https://launchpad.net/~aims Post to : aims@lists.launchpad.net Unsubscribe : https://launchpad.net/~aims More help : https://help.launchpad.net/ListHelp