check_linux_net_dev
Check Linux network interfaces without SNMP.
I was looking for a check plugin that...
- does not use SNMP
- provides all available interface metrics (incl. warn and crit thresholds if applicable) as performance data
- allows alarming on rx / tx bytes, rx / tx drops and rx / tx errors
So I came up with this little Python3 script.
Required modules:
- argparse
- json
- os
- sys
- time
Dependencies and prerequisites
This script was tested on Ubuntu 16.04 & 18.04 and RedHat / Centos 6 & 7. There are no root privileges required to read from /proc/net/dev.
This script needs a temp file to store the metrics from the last check and compare the delta. Per default, it will use /tmp/' + args.device + '_check_linux_net_dev.tmp. You can override this by specifying another file by using --temp-file you want to use another location due to any restrictions in your environment.
Usage
Run ./check_linux_net_dev -h for a detailed help message and overview of all supported parameters.
Examples
Without thresholds
./check_linux_net_dev -d wlan0 --svc-chk-interval 60 - network device statistics for wlan0
./check_linux_net_dev -d tun0 --svc-chk-interval 300 - network device statistics for tun0 with a service check interval of 300 seconds
With thresholds
./check_linux_net_dev -d wlan0 --svc-chk-interval 60 --tx-bytes-warn 300 - network device statistics for tun0 with a warning threshold for transmitted bytes of 300
./check_linux_net_dev -d wlan0 --svc-chk-interval 60 --tx-bytes-wanr 300 --rx-bytes-crit 3000 --tx-drops-crit 1000 --tx-errors-warn 100 same as above + additional thresholds
Roadmap for the next version:
- generic handling of thresholds for any value
- be more user-friendly (i.e. input validation and sanity checks & a warning if warn > crit)
- additional testing in container
- review for more robust error and exception handling
