feat(snmp): Add secret support for auth_password and priv_password

[srebhan]

Summary

Add support for secrets to all SNMP-family plugins.

Checklist

• No AI generated code was used in this PR

Related issues

resolves #14972

[telegraf-tiger]

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DEB	RPM	TAR GZ	ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz

[KoMa1978]

Hi,

it is not really working. This is my telegraf.conf with the secrets config (this one is working fine with "<< token = "@{localsecrets:influxdb_token}" >>"for influx):

[[secretstores.jose]]
  id = "localsecrets"
  path = "/etc/telegraf/secrets"
  password = "xxxx"

$ telegraf secrets list
Known secrets for store "localsecrets":
    influxdb_token                  
    snmpv3_operator_token           
    snmpv3_token              

[[inputs.snmp]]
...
  auth_protocol = "SHA"
  auth_password = "@{localsecrets:snmpv3_token}"
  priv_protocol = "AES"
  priv_password = "@{localsecrets:snmpv3_token}"

$telegraf --test --config /etc/telegraf/telegraf.d/snmp.conf.test 
2024-03-12T12:52:16Z I! Loading config: /etc/telegraf/telegraf.d/snmp.conf.test
2024-03-12T12:52:16Z E! unknown secret-store for "@{localsecrets:snmpv3_token}"

[KoMa1978]

Ignore the above ...

It is working fine, I forgot to add the telegraf config (where the secretstore is defined) in the test
This one is working fine:

$telegraf --test --config /etc/telegraf/telegraf.conf --config /etc/telegraf/telegraf.d/snmp.conf.test

[Hipska]

-				return GosnmpWrapper{}, fmt.Errorf("getting private password failed: %w", err)
+				return GosnmpWrapper{}, fmt.Errorf("getting privacy password failed: %w", err)