influxdata/telegraf

Support pod name as additional tag in Prometheus input plugin

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#16192 opened on Nov 14, 2024

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Description

Use Case

We deploy telegraf to scrape istio metrics in the prometheus format and forward them to our internal metric system. The Istio metrics come from multiple istio ingressgateway pods but Istio metrics do not have any existing tag to indicate which source pod they come from. In this case, our internal metric system would automatically aggregate metrics from different pods in a weird way so that the metric become basically unavailable.

I am aware that the Prometheus input plugin supports pod annotation and pod label as extra tag, but not pod name, which seems as useful as labels/annotations to me. Therefore I would like to suggest adding a configuration that injects pod name as an extra metric tag for the prometheus input plugin.

Expected behavior

Have a configuration for the prometheus input plugin called something like pod_name_tag, which takes a boolean value and defaults to false. If it is enabled, pod name is injected to all metrics collected by the prometheus input plugin, for example, source_pod_name: istio-ingressgateway-ase33.

Actual behavior

Pod name cannot be configured to be an extra tag on metrics collected by the prometheus plugin.

Additional info

I am glad to contribute if the community finds this feature request useful and would like to move forward with it. Thanks!

Contributor guide

Tech stack
go
Domain
backendobservabilitydata
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Go programmingUnderstanding of Telegraf plugin system
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Look into the Telegraf Prometheus input plugin, likely in 'plugins/inputs/prometheus/'. The request asks for a new config option `pod name tag` that, when true, adds the Kubernetes pod name as a metric tag. Implementing this would require understanding how the plugin currently handles pod annotations/labels and the config structure. Check if there are any existing discussions or PRs related to this feature. The issue is open and no maintainer response yet, so you may need to clarify the config field naming or explore how to reliably get the pod name.