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Support OpenMetrics 2.0 exposition format

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
45/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Active
Tech stack
prometheus, python

Research direction

Review the linked PRs (#1104, #1087) and issue #1122 to understand the current OpenMetrics support. Examine the client_golang PR #2132 for the implementation approach. The work involves modifying the exposition logic, likely in the core metrics generation and HTTP handler code, to negotiate and produce OpenMetrics 2.0 format. Testing will require verifying the output against the OpenMetrics 2.0 specification.

Written by the indexing model from the issue text.

Description

OpenMetrics 2.0 is now available (experimental): https://prometheus.io/docs/specs/om/open_metrics_spec_2_0/

Prometheus common have it implemented https://github.com/prometheus/common/issues/893
A PR is on the way for client_golang https://github.com/prometheus/client_golang/pull/2132

It would be nice for client_python to support exposing OpenMetrics 2.0 as well.

Proposed approach, mirroring what client_golang:

  • Keep a single existing opt-in switch for OpenMetrics exposition rather than adding a second flag specifically for 2.0.
  • Once OpenMetrics exposition is opted into, rely purely on content neciation.

Related work:

Dominant language
Python
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Forks
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Avg merge
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Merged PRs (30d)
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