Feature Request

Proposal:

Add a new option value_field = "whatever" that will set the field key used by the parser

Current behavior:

Parser always uses value as the field key.

Desired behavior:

Parse should allow user to provide an appropriately descriptive field key.

Use case:

We have experienced the same behavior with exec input plugin and data format:

[[inputs.exec]]
  commands = ["/bin/bash -c \"curl -s http://127.0.0.1:8080/tunnelcount | grep -Eo '[0-9]+'\""]
  data_format = "value"
  name_override = "tunnels_total"

# OUTPUTS

[[outputs.prometheus_client]]
  listen = ":9126"
  expiration_interval = "120s"
  collectors_exclude = ["gocollector", "process"]
  metric_version = 2

# It shows tunnels_total as metric name
telegraf --test --input-filter exec

However, the metric name in the endpoint is tunnels_total_value

Thank you

Originally posted by @AntonioAlfrz in #7171 (comment)