Support running the gateway with other reactive containers besides netty

[muzuro]

I am trying to use tomcat instead netty. To achive this i have excluded netty from dependencies and included tomcat, so my build.gradle dependecies:

dependencies {
    compile (group: 'org.springframework.cloud', name: 'spring-cloud-starter-gateway', version: '2.0.0.M4') {
        exclude group: 'org.springframework.boot', module: 'spring-boot-starter-netty'
    }
    compile group: 'org.springframework.boot', name: 'spring-boot-starter-tomcat', version: '2.0.0.M7'
    compile group: 'org.springframework.boot', name: 'spring-boot-starter-webflux'
}

Hower it is not enough, i get ClassCastException:

java.lang.ClassCastException: org.springframework.core.io.buffer.DefaultDataBufferFactory cannot be cast to org.springframework.core.io.buffer.NettyDataBufferFactory
	at org.springframework.cloud.gateway.filter.NettyWriteResponseFilter.lambda$filter$0(NettyWriteResponseFilter.java:61) ~[spring-cloud-gateway-core-2.0.0.M4.jar:2.0.0.M4]
	at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:44) ~[reactor-core-3.1.1.RELEASE.jar:3.1.1.RELEASE]
	at reactor.core.publisher.Mono.subscribe(Mono.java:2913) ~[reactor-core-3.1.1.RELEASE.jar:3.1.1.RELEASE]
	at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:167) ~[reactor-core-3.1.1.RELEASE.jar:3.1.1.RELEASE]

Is it possible to use tomcat with gateway instead netty?
Thanks!

[spencergibb]

Not currently.

[spencergibb]

I already have code for this that just needs to be formalized. The difficulty will be running all the tests with other containers.

[grku2opia]

@spencergibb can u provide code ?

[ghost]

@spencergibb How is the progress now? Thank you

[spencergibb]

None so far

[spencergibb]

@ghoddg this is likely not going to happen in 2.0.0. For now you have to use netty.

[spencergibb]

No

[ghoddg]

@spencergibb Thanks for update.

[ghoddg]

@spencergibb , from above communication, i got understanding that, API Gateway Service with Spring Cloud Gateway will not work with Tomcat as well as Weblogic for now and it will work only with netty.
is my understanding correct?

[dharezlak]

I just noticed that this error occurs only in the testing mode. When run normally the gateway forwarding works fine.

[dharezlak]

Another thing I noticed is that when I use WebClient in tests instead of WebTestClient all is fine. Should using WebTestClient in spring-gateway based applications be prohibited?

[spencergibb]

It's not. It is used to test the gateway

[dharezlak]

@spencergibb It is indeed. The source of my problem was using the @AutoConfigureWebTestClient annotation. Without it my tests are working fine. When I use it I get the ClassCastException mentioned earlier. Do you think this calls for a separate issue?

[drdamour]

are u open to pr's for tomcat support? for 2.0 or 2.1

[spencergibb]

@drdamour I already have code #145 (comment). The trouble is testing everything.

[drdamour]

yeah i assumed you meant unit test and thus PR.

what type of testing are you referring to then?

[spencergibb]

Basically all the integration tests. Anything that spins up a container then makes real network calls thru the gateway.

[drdamour]

k...how are you hoping to structure the tests...duality for every netty test have a tomcat test. or just abstract away the backing implementation in all the tests?

or is there some prior art you are looking to follow?

[spencergibb]

My guess is rerunning all the tests with some system properties. Copied tests is prohibitive. Most have a base class already.

[drdamour]

how will that work with your maven circle build? just 2+ surefire/failsafe executions?

[spencergibb]

jenkins is our canonical build

[spencergibb]

85193a0 may have fixed this functionality. The class cast exceptions mentioned here #145 (comment) are now gone.

Remaining items:

• Daily tests that run all tests against each of the other three containers. Possibly with maven profiles. @marcingrzejszczak thoughts?
• WebSocketClient per container (see here for appropiate class conditions)

// workaround for tomcat
@Bean
@Primary
TomcatWebSocketClient tomcatWebSocketClient() {
	return new TomcatWebSocketClient();
}

• ?

[marcingrzejszczak]

Hmm those would be tests inside the gateway or some separate ones? Cause we could even embed running those tests inside the gateway build.

[spencergibb]

Just all the tests already in gateway

[spencergibb]

See #1544 for progress

[jingbing]

@spencergibb Is it possible to use tomcat with gateway now?

[dlsrb6342]

Hi @spencergibb
I wanna use WebClientHttpRoutingFilter and WebClientWriteResponseFilter with Netty.
Is there any issue with Netty?
And is there any way to disable NettyRoutingFilter?

[spencergibb]

@dlsrb6342 it's unrelated to this issue. There's no way to disable the netty beans at this moment.

[gaurav1264]

Hi @spencergibb Any update when tomcat support will be added to Spring cloud gateway please?

[manisha-shetty]

Adding this to the webflux security config resolved the issue for me

`@Bean
@primary
public RequestUpgradeStrategy requestUpgradeStrategy() {
return new TomcatRequestUpgradeStrategy();
}

@bean
@primary
WebSocketClient tomcatWebSocketClient() {
return new TomcatWebSocketClient();
}`

[klaus-cicd]

New anomalies appear.

java.lang.ClassCastException: org.springframework.http.server.reactive.TomcatHttpHandlerAdapter$TomcatServerHttpRequest cannot be cast to javax.servlet.http.HttpServletRequest
at org.springframework.web.reactive.socket.server.upgrade.TomcatRequestUpgradeStrategy.getNativeRequest(TomcatRequestUpgradeStrategy.java:159)