Example: http://junglebp.atticlab.net/ATTICLAB.NET/JUNGLEBP.ATTICLAB.NET/index.html#eos
eos_balance, eos_chain, eos_net, eos_cpu, eos_quota - account related plugins...
eos_mem - EOS node memory consumption plugin
echo "[eos_*]
env.ACCOUNT eosaccount
env.DATADIR /opt/EOSmainNet
" >> /etc/munin/plugin-conf.d/eos
... where DATADIR path to your nodeos catalog with blocks and state catlogs
just place plugin in /usr/share/munin/plugins
$ sudo chmod 755 /usr/share/munin/plugins/eos*
$ sudo ln -s /usr/share/munin/plugins/eos* /etc/munin/plugins/
$ sudo service munin-node restart