fix httpclient5.x connection leak

[JoeCqupt]

#3696

[spencergibb]

So this change breaks the build in the retry tests.

Error:    RetryFilterFunctionTests.retryBodyWorks:91 Status expected:<200 OK> but was:<500 INTERNAL_SERVER_ERROR>
Error:    RetryFilterFunctionTests.retryWorks:72 Status expected:<200 OK> but was:<500 INTERNAL_SERVER_ERROR>

[spencergibb]

Hmm, locally they pass. Rerunning build.

[spencergibb]

Any idea how to test this? The test in the reproducer in #3696 doesn't pass with this fix.

[JoeCqupt]

Any idea how to test this? The test in the reproducer in #3696 doesn't pass with this fix.

the reproducer code with some error config . the route uri not match mock server .

[JoeCqupt]

@spencergibb @ryanjbaxter PTAL

[ryanjbaxter]

Could we use the reproducer as a basis for a test?

[JoeCqupt]

Could we use the reproducer as a basis for a test?

i have use the reproducer code as a basis add a unit test .

Let me explain the code which i modified:

first i add httpclient5 maven dependency for test

<dependency>
    <groupId>org.apache.httpcomponents.client5</groupId>
    <artifactId>httpclient5</artifactId>
    <scope>test</scope>
</dependency>

but this changed the underlying implementation of ProxyExchange : change from REACTOR to HTTP_COMPONENTS . refer to ClientHttpRequestFactoryBuilder

so i add config to application.yml ：

spring:
  http:
    client:
      factory: REACTOR

After modifying the config , I modified two associated unit tests：
GatewayServerMvcAutoConfigurationTests#gatewayHttpClientPropertiesWork
GatewayServerMvcAutoConfigurationTests#settingHttpClientFactoryWorks

Finally i add a unit test to test httpcommonts as the underlying implementation of ProxyExchange

@ryanjbaxter @spencergibb PTAL

[ryanjbaxter]

Can you elaborate on why you needed to add httpclient5?

[JoeCqupt]

Can you elaborate on why you needed to add httpclient5?

because the reproducer code use httpclient5 as the underlying implementation of ProxyExchange

issue : #3696
reproducer code: https://github.com/johan1a/spring-cloud-gateway-mvc-connection-test/blob/master/src/main/java/com/example/demo/HttpComponentsConfig.java#L14-L20

[spencergibb]

@JoeCqupt unfortunately, adding the Apache httpclient 5 dependency will change the underlying http client for all the tests. You would need to add a new integration test module to not pollute the classpath here https://github.com/spring-cloud/spring-cloud-gateway/tree/main/spring-cloud-gateway-integration-tests

[JoeCqupt]

@JoeCqupt unfortunately, adding the Apache httpclient 5 dependency will change the underlying http client for all the tests. You would need to add a new integration test module to not pollute the classpath here https://github.com/spring-cloud/spring-cloud-gateway/tree/main/spring-cloud-gateway-integration-tests

OK i will add a new integration test

[ryanjbaxter]

Can you submit this against the 4.1.x branch?

[JoeCqupt]

Can you submit this against the 4.1.x branch?

i have changed the base branch to 4.1.x