SNMP: Linux software RAID state

Compile snmp-swraid
apt-get install -y git make build-essential libsnmp-dev
export GIT_SSL_NO_VERIFY=true
git clone https://github.com/jrossi/snmp-swraid.git /tmp/snmp-swraid
cd /tmp/snmp-swraid
make

tar cjf snmp-swraid.ubuntu-$(lsb_release -sr).tar.bz2 SWRAID-MIB.txt swRaidPlugin.so

# install
apt-get install -y snmpd snmp-mibs-downloader
wget -q http://dl.panticz.de/snmp-swraid/snmp-swraid.ubuntu-$(lsb_release -sr).tar.bz2 -O /tmp/snmp-swraid.ubuntu.tar.bz2
tar xjf /tmp/snmp-swraid.ubuntu.tar.bz2 -C /tmp
cp /tmp/SWRAID-MIB.txt $(find /var/lib -name ietf)
cp /tmp/swRaidPlugin.so /usr/lib
echo "dlmod swRaidMIB /usr/lib/swRaidPlugin.so" >> /etc/snmp/snmpd.conf
service snmpd restart

# snmpwalk -v1 -c public -m+SWRAID-MIB localhost swRaidMIB
SWRAID-MIB::swRaidIndex.1 = INTEGER: 1
SWRAID-MIB::swRaidDevice.1 = STRING: md0
SWRAID-MIB::swRaidPersonality.1 = STRING: raid1
SWRAID-MIB::swRaidUnits.1 = STRING: sdb1[1] sda1[0]
SWRAID-MIB::swRaidUnitCount.1 = INTEGER: 2
SWRAID-MIB::swRaidStatus.1 = INTEGER: active(2)
SWRAID-MIB::swRaidErrorFlag.0 = INTEGER: 0
SWRAID-MIB::swRaidErrMessage.0 = STRING:

# snmpwalk -v2c -c public backup.example.com .1.3.6.1.4.1.2021.13.18
iso.3.6.1.4.1.2021.13.18.1.1.1.1 = INTEGER: 1
iso.3.6.1.4.1.2021.13.18.1.1.2.1 = STRING: "md127"
iso.3.6.1.4.1.2021.13.18.1.1.3.1 = STRING: "raid1"
iso.3.6.1.4.1.2021.13.18.1.1.4.1 = STRING: "sda1[0] sdb1[1](F)"
iso.3.6.1.4.1.2021.13.18.1.1.5.1 = INTEGER: 2
iso.3.6.1.4.1.2021.13.18.1.1.6.1 = INTEGER: 3
iso.3.6.1.4.1.2021.13.18.100.0 = INTEGER: 1
iso.3.6.1.4.1.2021.13.18.101.0 = STRING: "Failed RAID devices: md127 "

# enable remote access
sed -i 's|127.0.0.1||g' /etc/snmp/snmpd.conf
sed -i 's|default.*-V.*systemonly||g' /etc/snmp/snmpd.conf
service snmpd restart

Links
https://wiki.opennms.org/wiki/Linux_Mdadm_monitoring_thru_snmp
https://github.com/jrossi/snmp-swraid