check_lxc
Monitoring plugin to check LXC (Linux Container)
Full documentation: https://www.claudiokuenzler.com/monitoring-plugins/check_lxc.php
Usage
sudo ./check_lxc.sh -n container -t type [-u unit] [-w warning] [-c critical]
sudo needed
check_lxc.sh requires to be run with root privileges because certain commands within the plugin require elevated permissions. Therefore create an entry in /etc/sudoers similar to this (adapt to your own environment):
nagios ALL = NOPASSWD: /usr/lib/nagios/plugins/check_lxc.sh
If you use NRPE, the corresponding command definition could look like this:
command[check_lxc]=sudo /usr/lib/nagios/plugins/check_lxc.sh -n $ARG1$ -t $ARG2$
Options and check types explained
Options:
-n name of container (or ALL for some types)
-t type to check (see list below)
[-u unit of output values (k|m|g)]
[-w warning threshold] (makes only sense if limit is set in lxc config)
[-c critical threshold] (makes only sense if limit is set in lxc config)
[-s sleep in seconds between cpu checks]
Types:
mem -> Check the memory usage of the given container (thresholds in percent)
swap -> Check the swap usage (thresholds in MB)
cpu -> Check cpu usage (percentage) of a container (thresholds in percent)
auto -> Check autostart of container (-n ALL possible)
Examples (container name: lxctest01)
./check_lxc.sh -n lxctest01 -t mem
LXC lxctest01 OK - Used Memory: 96 MB|mem_used=100941824B;0;0;0;
./check_lxc.sh -n lxctest01 -t mem -w 2 -c 54
LXC lxctest01 WARNING - Used Memory: 2% (97 MB)|mem_used=101982208B;0;0;0;4294967296
./check_lxc.sh -n lxctest01 -t mem -w 85 -c 95 -u k
LXC lxctest01 OK - Used Memory: 2% (98600 KB)|mem_used=100966400B;0;0;0;4294967296
./check_lxc.sh -n ALL -t auto
LXC AUTOSTART CRITICAL: lxctest01
./check_lxc.sh -n lxctest01 -t swap -w 50 -c 70
LXC lxctest01 CRITICAL - Used Swap: 81 MB|swap=85680128B;52428800;73400320;0;0
./check_lxc.sh -n lxctest01 -t cpu -w 80 -c 90
LXC lxctest01 OK - CPU Usage: 27%|cpu=27%;80;90;0;0
Enable cgroup memory for memory check
To be able to run the memory check (-t mem), the cgroup subsys "memory" must be enabled. You can verify this manually by running:
cat /proc/cgroups | grep memory
If the first value is not enabled (0), then add the following options as your kernel boot parameter: "cgroup_enable=memory" and "swapaccount=1". In Debian this can be done by modifying /etc/default/grub2 followed by a update of the grub2 and reboot:
# cat /etc/default/grub | grep CMDLINE_LINUX_DEFAULT
GRUB_CMDLINE_LINUX_DEFAULT="quiet cgroup_enable=memory swapaccount=1"
update-grub2
reboot
Then verify if you can get the memory statistics of a container:
lxc-cgroup -n lxctest01 memory.stat