Translate snmp field values

[LeadingMoominExpert]

Required for all PRs:

• Signed CLA.
• Associated README.md updated.
• Has appropriate unit tests.

Fixes #8458

[srebhan]

@LeadingMoominExpert you need to add the description of the new option also to the sampleConfig variable.
Furthermore, I'm not sure if your testcase actually is suited to test the translate functionality as you specify the name in the tbl. How can you see if it is actually overwritten using the translation?

[LeadingMoominExpert]

@srebhan I modified the tests so that a field returns an OID value with cases of this value being translated and not translated with mocked snmptranslate command.

[LeadingMoominExpert]

I also did not include the translate functionality in sampleConfig as it seems to only have descriptions of the plugin definitions and not table or field definitions.

telegraf/plugins/inputs/snmp/snmp.go

Lines 25 to 69 in a51a9a8

	const sampleConfig = `
	## Agent addresses to retrieve values from.
	## example: agents = ["udp://127.0.0.1:161"]
	## agents = ["tcp://127.0.0.1:161"]
	agents = ["udp://127.0.0.1:161"]
	## Timeout for each request.
	# timeout = "5s"
	## SNMP version; can be 1, 2, or 3.
	# version = 2
	## Agent host tag; the tag used to reference the source host
	# agent_host_tag = "agent_host"
	## SNMP community string.
	# community = "public"
	## Number of retries to attempt.
	# retries = 3
	## The GETBULK max-repetitions parameter.
	# max_repetitions = 10
	## SNMPv3 authentication and encryption options.
	##
	## Security Name.
	# sec_name = "myuser"
	## Authentication protocol; one of "MD5", "SHA", or "".
	# auth_protocol = "MD5"
	## Authentication password.
	# auth_password = "pass"
	## Security Level; one of "noAuthNoPriv", "authNoPriv", or "authPriv".
	# sec_level = "authNoPriv"
	## Context Name.
	# context_name = ""
	## Privacy protocol used for encrypted messages; one of "DES", "AES" or "".
	# priv_protocol = ""
	## Privacy password used for encrypted messages.
	# priv_password = ""
	## Add fields and tables defining the variables you wish to collect. This
	## example collects the system uptime and interface variables. Reference the
	## full plugin documentation for configuration details.
	`

[srebhan]

Fair enough. :-) Looks good.

[Hipska]

Does this also solve #6330? And could you give an example output with the function enabled? Thanks.

[ssoroka]

Looks like it doesn't solve it for integer fields.