Add metrics_prefix to discovery block

[vitkyrka]

What does this PR do?

Adds a metrics_prefix field to the discovery block of auto_conf.yaml for gearmand, krakend, and prefect — the three integrations whose metric prefix diverges from their check name and that currently ship a discovery block.

This allows the core agent to detect conflicts with a generic openmetrics/prometheus config. See https://datadoghq.atlassian.net/wiki/spaces/DSCVR/pages/7031522288/ for more information.

This is an alternative to #24738 which computed the metrics_prefix value automatically at ddev validate config time, by reading each integration's manifest.json or, for integrations without one, the repo's .ddev/config.toml [overrides.metrics-prefix] table (the same source ddev validate metadata already consults). Code owners objected to that approach since it made .ddev/config.toml — a file intended as developer/tooling configuration — production-critical.

This PR instead hand-authors the value directly in each affected integration's spec.yaml, so it's an explicit, reviewable part of the integration's own spec rather than a side effect of unrelated dev tooling. auto_conf.yaml remains a generated file (regenerated here via ddev validate config).

Motivation

https://datadoghq.atlassian.net/browse/DSCVR-640

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Add qa/required if this PR needs QA validation, or qa/skip-qa if it does not. Exactly one of the two is required.
• If you need to backport this PR to another branch, you can add the backport/<branch-name> label to the PR and it will automatically open a backport PR once this one is merged

[cit-pr-commenter-54b7da]

evalya-impact-summary

evalya impact analysis

Impact analysis: 0 selected, 0 skipped (of 0 test tasks)
Publish tasks:   0 (always emitted)
Diff (9 files):
  gearmand/assets/configuration/spec.yaml
  gearmand/changelog.d/24861.added
  gearmand/datadog_checks/gearmand/data/auto_conf.yaml
  krakend/assets/configuration/spec.yaml
  krakend/changelog.d/24861.added
  krakend/datadog_checks/krakend/data/auto_conf.yaml
  prefect/assets/configuration/spec.yaml
  prefect/changelog.d/24861.added
  prefect/datadog_checks/prefect/data/auto_conf.yaml

Debug a specific task: evalya plan impact --path <path> --task <task>

Learn more about CI impact filtering

[datadog-official]

 

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 87.79% (-0.72%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: e35aa9d | Docs | Datadog PR Page | Give us feedback!}

[dd-octo-sts]

Validation Report

All 21 validations passed.

Show details

Validation	Description	Status
agent-reqs	Verify check versions match the Agent requirements file	✅
ci	Validate CI configuration and code coverage settings	✅
codeowners	Validate every integration has a CODEOWNERS entry	✅
config	Validate default configuration files against spec.yaml	✅
dep	Verify dependency pins are consistent and Agent-compatible	✅
http	Validate integrations use the HTTP wrapper correctly	✅
imports	Validate check imports do not use deprecated modules	✅
integration-style	Validate check code style conventions	✅
jmx-metrics	Validate JMX metrics definition files and config	✅
labeler	Validate PR labeler config matches integration directories	✅
legacy-signature	Validate no integration uses the legacy Agent check signature	✅
license-headers	Validate Python files have proper license headers	✅
licenses	Validate third-party license attribution list	✅
metadata	Validate metadata.csv metric definitions	✅
models	Validate configuration data models match spec.yaml	✅
openmetrics	Validate OpenMetrics integrations disable the metric limit	✅
package	Validate Python package metadata and naming	✅
qa-label	Validate the pull request declares whether it needs QA for the next Agent release	✅
readmes	Validate README files have required sections	✅
saved-views	Validate saved view JSON file structure and fields	✅
version	Validate version consistency between package and changelog	✅

View full run