Fix CdnSampleTests.testManageCdnProfileWithCustomDomain

[alzimmermsft]

In Linux environments this test is throwing an UnknownHostException when this line of code is called. The resulting stack trace is

reactor.core.Exceptions$ReactiveException: java.net.UnknownHostException: 0e734f9fc000001: 0e734f9fc000001: Name or service not known
	at reactor.core.Exceptions.propagate(Exceptions.java:392)
	at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:97)
	at reactor.core.publisher.Mono.block(Mono.java:1707)
	at com.azure.resourcemanager.resources.fluentcore.model.implementation.CreatableUpdatableImpl.create(CreatableUpdatableImpl.java:255)
	at com.azure.resourcemanager.resources.fluentcore.model.implementation.CreatableUpdatableImpl.create(CreatableUpdatableImpl.java:29)
	at com.azure.resourcemanager.cdn.samples.ManageCdnWithCustomDomain.runSample(ManageCdnWithCustomDomain.java:72)
	at com.azure.resourcemanager.samples.CdnSampleTests.testManageCdnProfileWithCustomDomain(CdnSampleTests.java:14)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)
	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
	at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
	at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:214)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:210)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:66)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
	at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService$ExclusiveTask.compute(ForkJoinPoolHierarchicalTestExecutorService.java:185)
	at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService.invokeAll(ForkJoinPoolHierarchicalTestExecutorService.java:129)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
	at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService$ExclusiveTask.compute(ForkJoinPoolHierarchicalTestExecutorService.java:185)
	at java.base/java.util.concurrent.RecursiveAction.exec(RecursiveAction.java:194)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)
	Suppressed: java.lang.Exception: #block terminated with an error
		at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:99)
		... 53 more
Caused by: java.net.UnknownHostException: 0e734f9fc000001: 0e734f9fc000001: Name or service not known
	at java.base/java.net.InetAddress.getLocalHost(InetAddress.java:1647)
	at com.azure.resourcemanager.appservice.implementation.AppServiceDomainImpl.lambda$createResourceAsync$0(AppServiceDomainImpl.java:87)
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:125)
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1816)
	at reactor.core.publisher.MonoCollectList$MonoCollectListSubscriber.onComplete(MonoCollectList.java:129)
	at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:144)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.checkTerminated(FluxFlatMap.java:846)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.drainLoop(FluxFlatMap.java:608)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.drain(FluxFlatMap.java:588)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.onComplete(FluxFlatMap.java:465)
	at reactor.core.publisher.FluxExpand$ExpandBreathSubscriber.drainQueue(FluxExpand.java:168)
	at reactor.core.publisher.FluxExpand.subscribeOrReturn(FluxExpand.java:71)
	at reactor.core.publisher.InternalFluxOperator.subscribe(InternalFluxOperator.java:55)
	at reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:54)
	at reactor.core.publisher.InternalFluxOperator.subscribe(InternalFluxOperator.java:62)
	at com.azure.core.util.paging.ContinuablePagedFluxCore.subscribe(ContinuablePagedFluxCore.java:244)
	at com.azure.core.http.rest.PagedFluxBase.subscribe(PagedFluxBase.java:220)
	at reactor.core.publisher.Mono.subscribe(Mono.java:4397)
	at reactor.core.publisher.MonoSubscribeOn$SubscribeOnSubscriber.run(MonoSubscribeOn.java:126)
	at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:84)
	at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:37)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.net.UnknownHostException: 0e734f9fc000001: Name or service not known
	at java.base/java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
	at java.base/java.net.InetAddress$PlatformNameService.lookupAllHostAddr(InetAddress.java:933)
	at java.base/java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1519)
	at java.base/java.net.InetAddress$NameServiceAddresses.get(InetAddress.java:852)
	at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1509)
	at java.base/java.net.InetAddress.getLocalHost(InetAddress.java:1642)
	... 25 more

This appears to be due to a change in the DevOps Linux environment as this code has been unmodified for a while and only happens while in a Linux environment, not macOS or Windows.

[weidongxu-microsoft]

1. we can wait a while for response from EngSys.
2. then we can see if we use a static hostname, or a default one if Java call does not work.
3. if above not work, we can keep it as it is. tests on Windows should be good enough for our case.

[mikeharder]

I created a minimal app and pipeline to repro this, but I don't see the API failing. Can you try again?

Repo: https://github.com/mikeharder/AzurePipelineTests/tree/java-hostname

Run: https://dev.azure.com/azure-sdk/playground/_build/results?buildId=1754451&view=logs&j=774eaf24-5336-55da-d764-6724e371398c

[weidongxu-microsoft]

@XiaofeiCao Do you have change to check?

[XiaofeiCao]

@weidongxu-microsoft OK, I'll start investigate.

[XiaofeiCao]

I enabled the test on linux in my personal repo and it passed ci.

change: https://github.com/Azure/azure-sdk-for-java/commit/51ab1463af5f11b83bac3274da5c589b20d3fff7

run: https://dev.azure.com/azure-sdk/playground/_build/results?buildId=1780395&view=logs&j=6438ed74-af23-540e-94f3-38d1eefc9e9b&t=2d3af076-e540-5b98-fba0-cc7b8b21203d&l=908

Maybe I create a PR to re-enable it on linux and see if it works?

[XiaofeiCao]

PR: https://github.com/Azure/azure-sdk-for-java/pull/30460

ci passed, seems no issue now

[weidongxu-microsoft]

Should we double check the place we call Inet4Address.getLocalHost() and check whether we can safely assume user machine can get its IP address? If not, when machine cannot get IP address, should we fail or fallback?