Retry when Spring tests fails to start a Server with a random port obtained in advance

[ikhoon]

Motivation:

If a random port (0) for internal services or managed services is
specified in Spring configuration, the Spring integration module
allocate available ports early and use them to configure additional
service later.

armeria/spring/boot2-actuator-autoconfigure/src/main/java/com/linecorp/armeria/spring/actuate/ArmeriaSpringActuatorAutoConfiguration.java

Lines 258 to 260 in 948763a

	if (port == 0) {
	port = SocketUtils.findAvailableTcpPort();
	}

This is not a problem in production mode.
However, in testing situations, many test servers are started simultaneously
with a random port and the available ports can be acquired by them. #4391 #4329

Modifications:

• Add RetryableArmeriaServerGracefulShutdownLifecycle to retry a
  server with a backoff at most N times.

Result:

• This is not a perfect answer for the failure but it might reduce the
  number of failures.
• Fixes Test failure: com.linecorp.armeria.spring.actuate.ArmeriaSpringActuatorAutoConfigurationSecureTest.normal() #4391 Test failure: LocalArmeriaPortHttpsTest.testPortConfiguration #4329

[codecov]

Codecov Report

Merging #4395 (9c38f92) into master (de36a8b) will decrease coverage by 0.03%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #4395      +/-   ##
============================================
- Coverage     73.84%   73.81%   -0.04%     
- Complexity    17702    17718      +16     
============================================
  Files          1505     1509       +4     
  Lines         66105    66198      +93     
  Branches       8309     8313       +4     
============================================
+ Hits          48815    48862      +47     
- Misses        13296    13330      +34     
- Partials       3994     4006      +12     

Impacted Files	Coverage Δ
...meria/spring/AbstractArmeriaAutoConfiguration.java	71.42% <ø> (ø)
...ecorp/armeria/server/LengthBasedServiceNaming.java	75.00% <0.00%> (-16.67%)	⬇️
...armeria/internal/common/stream/SubscriberUtil.java	72.22% <0.00%> (-11.12%)	⬇️
...m/linecorp/armeria/client/DecodedHttpResponse.java	85.00% <0.00%> (-5.00%)	⬇️
...meria/client/DefaultDnsQueryLifecycleObserver.java	76.81% <0.00%> (-2.90%)	⬇️
...rmeria/common/stream/ConcatArrayStreamMessage.java	83.14% <0.00%> (-2.25%)	⬇️
.../linecorp/armeria/client/Http2ResponseDecoder.java	70.62% <0.00%> (-2.10%)	⬇️
...ecorp/armeria/server/ParameterizedPathMapping.java	91.76% <0.00%> (-1.18%)	⬇️
...eria/internal/common/AbstractKeepAliveHandler.java	81.42% <0.00%> (-1.10%)	⬇️
...rp/armeria/common/stream/DefaultStreamMessage.java	89.47% <0.00%> (-1.06%)	⬇️
... and 22 more

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[jrhee17]

Question) Would it be possible to just pass 0 for the internal/management port? (The same as we do when we create a ServerExtension).
Asking because it seems like SocketUtils will be deprecated (and has been removed).

ref: spring-projects/spring-framework#28052

[minwoox]

Would it be possible to just pass 0 for the internal/management port? (The same as we do when we create a ServerExtension).

That's a good idea. 👍 We could probably pass 0 and let Armeria find the available port.

[ikhoon]

Asking because it seems like SocketUtils will be deprecated (and has been removed).

We can easily migrate SocketUtils.findAvailableTcpPort() with our own code like we did in

armeria/zookeeper3/src/test/java/com/linecorp/armeria/common/zookeeper/ZooKeeperTestUtil.java

Lines 49 to 67 in 1b4cd2a

	private static int[] unusedPorts(int numPorts) {
	final int[] ports = new int[numPorts];
	final Random random = ThreadLocalRandom.current();
	for (int i = 0; i < numPorts; i++) {
	for (;;) {
	final int candidatePort = random.nextInt(64512) + 1024;
	try (ServerSocket ss = new ServerSocket()) {
	ss.bind(new InetSocketAddress("127.0.0.1", candidatePort));
	ports[i] = candidatePort;
	break;
	} catch (IOException e) {
	// Port in use or unable to bind.
	continue;
	}
	}
	}
	return ports;
	}

Would it be possible to just pass 0 for the internal/management port?

But it is a different issue. Internal services use port-based virtual hosting that needs a pre-known port number.

armeria/core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java

Lines 1446 to 1447 in 91c787f

	public VirtualHostBuilder virtualHost(int port) {
	checkArgument(port >= 1 && port <= 65535, "port: %s (expected: 1-65535)", port);

So I'd like to leave it as a known issue.

[minwoox]

👍 👍 👍

[ikhoon]

This PR has been reverted because the changes cause build failures with Spring Boot 2.7.3
https://github.com/line/armeria/runs/8243288221?check_suite_focus=true