All scripts are written in standard shell language, and /bin/sh would be sufficient. They are tailored and will run on FreeBSD. You need to install lang/gawk in order to run intr_ plugin.

Setup

Make sure sysutils/munin-node is installed
Enable munin-node to run at startup: sysrc munin_node_enable YES
Clone this repo and copy all scripts to /usr/local/share/munin/plugins
run munin-node-configure --suggest and see if the plugins are detected.
run munin-node-configure --shell | sh -x to make appropriate symlinks
restart munin-node if running: service munin-node restart

Plugins

intr_ graphs IRQ and CPU timers, taken from vmstat -i output
netisr_ graphs per-thread/per-protocol netisr(9) statistics, taken from netstat -Q
netmem_ graphs mbuf(9) statistics, taken from netstat -m
pf_ graphs pf(4) firewall statistics, taken from pfctl -vsi
udp_ graphs UDP protocol traffic and error statistcs, taken from netstat -s