HDDS-15827. Wait for SCM pipelines in TestDnRatisLogParser

[jojochuang]

Summary

• Wait for SCM to report at least one pipeline before TestDnRatisLogParser reads getPipelines().get(0).

• Avoids intermittent IndexOutOfBoundsException: Index 0 out of bounds for length 0 when pipeline creation lags behind waitForClusterToBeReady().

• Flaky test failure seen in https://github.com/jojochuang/ozone/actions/runs/29121968977/job/86461225819

Jira

https://issues.apache.org/jira/browse/HDDS-15827

Problem

testRatisLogParsing uses a single-datanode mini-cluster and immediately indexes the first SCM pipeline. In CI, the pipeline list can still be empty when the test runs, even though the cluster is marked ready.

Test plan

• checkstyle on ozone-integration-test module
• mvn -pl :ozone-integration-test test -Dtest=TestDnRatisLogParser -DskipShade -DskipRecon -DskipDocs

Made with Cursor

[Copilot]

Pull request overview

This PR fixes an intermittent failure in the TestDnRatisLogParser integration test by waiting for SCM to report at least one pipeline before indexing getPipelines().get(0), preventing IndexOutOfBoundsException when pipeline creation lags behind cluster readiness.

Changes:

• Add a GenericTestUtils.waitFor(...) guard to ensure the SCM pipeline list is non-empty before accessing the first pipeline ID.

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[smengcl]

Thanks @jojochuang for the fix.