SNMPで自宅内ネットワークの監視

Ubuntu Server 24

code:sh

sudo apt install snmp

RTX1200に入れておく。prometheusサーバのIP

code:config

snmpv2c host <server IP>

snmpv2c community read-only public

やってみる

code:sh

snmpwalk -v 2c -c public <RTX1200のIP>

→いっぱい流れてきた。

たとえばホスト名を出してみる

code:txt

prometheus@prometheus:~$ snmpwalk -v 2c -c public 192.168.100.1 .1.3.6.1.2.1.1.5.0

iso.3.6.1.2.1.1.5.0 = STRING: "rtx1200"

標準mibはデフォルトで無効化されてるらしい。

code:diff

# As the snmp packages come without MIB files due to license reasons, loading

# of MIBs is disabled by default. If you added the MIBs you can reenable

# loading them by commenting out the following line.

-# mibs :

+mibs :

# If you want to globally change where snmp libraries, commands and daemons

# look for MIBS, change the line below. Note you can set this for individual

# tools with the -M option or MIBDIRS environment variable.

#

# mibdirs /usr/share/snmp/mibs:/usr/share/snmp/mibs/iana:/usr/share/snmp/mibs/ietf

めちゃくちゃエラーが出る。

https://scrapbox.io/files/6737745318c87a6212419269.png

ここにいろいろ描いてある。

MIBはここから落とせるらしい。

とりあえず入れてみる

code:sh

sudo cp yamaha-private-mib/* /usr/share/snmp/mibs/

→解決しない

https://scrapbox.io/files/6737759eb5fe8575ab858d9d.png

https://scrapbox.io/files/673776000a4cb35e0c378515.png

code:sh

apt -y install snmp snmp-mibs-downloader

で解決。

https://scrapbox.io/files/67377a44356bf845f2c8008b.png

https://scrapbox.io/files/67377aa318c87a621241aa50.png

snmp_exporterを入れる。

generatorする

code:sh

sudo apt-get install unzip build-essential libsnmp-dev

go install github.com/prometheus/snmp_exporter/generator@latest

よくわからん

これでやってみる

code:sh

git clone git@github.com:prometheus/snmp_exporter.git

cd snmp_exporter/generator

make mibs

code:sh

docker run -it -v "${PWD}:/opt/" prom/snmp-generator generate # build

~/snmp_exporter-0.26.0.linux-amd64/snmp_exporter --config.file=./snmp.yml # run

code:sh

~/go/bin/generator generate -m ./mibs -g ./generator.yml -o ./snmp.yml

これでもOK。

エラーが出たので悪いやつを消す。

https://scrapbox.io/files/6737812726c76ede85b7f859.png

code:generator.yml

auths:

auth_name:

version: 2 # SNMP version to use. Defaults to 2.

# 1 will use GETNEXT, 2 and 3 use GETBULK.

# Community string is used with SNMP v1 and v2. Defaults to "public".

community: public

# v3 has different and more complex settings.

# Which are required depends on the security_level.

# The equivalent options on NetSNMP commands like snmpbulkwalk

# and snmpget are also listed. See snmpcmd(1).

username: user # Required, no default. -u option to NetSNMP.

security_level: noAuthNoPriv # Defaults to noAuthNoPriv. -l option to NetSNMP.

# Can be noAuthNoPriv, authNoPriv or authPriv.

password: pass # Has no default. Also known as authKey, -A option to NetSNMP.

# Required if security_level is authNoPriv or authPriv.

auth_protocol: MD5 # MD5, SHA, SHA224, SHA256, SHA384, or SHA512. Defaults to MD5. -a option to NetSNMP.

# Used if security_level is authNoPriv or authPriv.

priv_protocol: DES # DES, AES, AES192, AES256, AES192C, or AES256C. Defaults to DES. -x option to NetSNMP.

# Used if security_level is authPriv.

priv_password: otherPass # Has no default. Also known as privKey, -X option to NetSNMP.

# Required if security_level is authPriv.

context_name: context # Has no default. -n option to NetSNMP.

# Required if context is configured on the device.

modules:

yamaha_rt_v2c: # SNMPv2cでのサンプル

walk:

- sysUpTime

lookups:

lookup: ifAlias

overrides:

ifAlias:

ignore: true # Lookup metric

ifDescr:

ignore: true # Lookup metric

ifName:

ignore: true # Lookup metric

ifType:

type: EnumAsInfo

# version: 2

max_repetitions: 25

retries: 3

timeout: 10s

snmp_exporterを開くとこれ。

https://scrapbox.io/files/6737824f0ee8c3f9dd31fc55.png

https://scrapbox.io/files/6737833a4c276239b301f8d1.png

出ました

運用が面倒なのでMakefileをかいた

code:Makefile

.PHONY: all generate reload

all: generate reload

generate:

/home/prometheus/go/bin/generator generate -m ./mibs -g ./generator.yml -o /etc/snmp_generator.yml

reload:

systemctl restart snmp_exporter

code:sh

sudo make