RFR: 8374364: TestCgroupMetrics.java fails when docker service unavailable

[SendaoYan]

On Fri, 26 Dec 2025 03:02:56 GMT, Jie Fu <jiefu at openjdk.org> wrote:

> So `MetricsTester.main(args)` requires the docker service, right?
> 
> Maybe it would be better to add this check in a place like`MetricsTester`, where it requires docker service directly.

Only jdk/internal/platform/cgroup/TestCgroupMetrics.java observed fails when docker service unavailable. There are total two tests invoke MetricsTester. The other test jdk/internal/platform/docker/TestSystemMetrics.java already call `DockerTestUtils.checkCanTestDocker()` [before start test](https://github.com/openjdk/jdk/tree/master/test/jdk/jdk/internal/platform/docker/TestSystemMetrics.java#L45). So i think it's better to leave this check inside test, same like to jdk/internal/platform/docker/TestSystemMetrics.java.

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PR Comment: https://git.openjdk.org/jdk/pull/28996#issuecomment-3692198076