Saga example

[zhfeng]

I'm working on the camel-saga-quickstart to run with the camel-k.

At first, I added the detection to check "*\.saga\(\).*" and add camel-lra dependency. It works fine and I get the example running but throws exception

Exception in thread "main" org.apache.camel.FailedToCreateRouteException: Failed to create route route1 at: >>> Saga -> [[SetHeader[id, header(CamelTimerCounter)], SetHeader[CamelHttpMethod, POST], Log[Executing saga #${header.id}], To[http://camel-saga-train-service:8080/api/train/buy/seat], To[http://camel-saga-flight-service:8080/api/flight/buy]]] <<< in route: Route(route1)[From[timer:clock?period=5s] -> [Saga -> [[SetH... because of Cannot find a CamelSagaService
	at org.apache.camel.reifier.RouteReifier.doCreateRoute(RouteReifier.java:379)
	at org.apache.camel.reifier.RouteReifier.createRoute(RouteReifier.java:108)
	at org.apache.camel.impl.DefaultModel.start(DefaultModel.java:326)
	at org.apache.camel.impl.DefaultModel.startRoute(DefaultModel.java:300)
	at org.apache.camel.impl.DefaultModel.startRouteDefinitions(DefaultModel.java:293)
	at org.apache.camel.impl.DefaultModel.startRouteDefinitions(DefaultModel.java:272)
	at org.apache.camel.impl.AbstractModelCamelContext.startRouteDefinitions(AbstractModelCamelContext.java:322)
	at org.apache.camel.impl.engine.AbstractCamelContext.doStartCamel(AbstractCamelContext.java:2590)
	at org.apache.camel.impl.engine.AbstractCamelContext.lambda$doStart$2(AbstractCamelContext.java:2438)
	at org.apache.camel.impl.engine.AbstractCamelContext.doWithDefinedClassLoader(AbstractCamelContext.java:2455)
	at org.apache.camel.impl.engine.AbstractCamelContext.doStart(AbstractCamelContext.java:2436)
	at org.apache.camel.support.service.ServiceSupport.start(ServiceSupport.java:99)
	at org.apache.camel.impl.engine.AbstractCamelContext.start(AbstractCamelContext.java:2345)
	at org.apache.camel.k.main.ApplicationRuntime$MainAdapter.doStart(ApplicationRuntime.java:177)
	at org.apache.camel.support.service.ServiceSupport.start(ServiceSupport.java:99)
	at org.apache.camel.main.MainSupport.run(MainSupport.java:77)
	at org.apache.camel.k.main.ApplicationRuntime.run(ApplicationRuntime.java:70)
	at org.apache.camel.k.main.Application.main(Application.java:42)
Caused by: org.apache.camel.RuntimeCamelException: Cannot find a CamelSagaService
	at org.apache.camel.reifier.SagaReifier.findSagaService(SagaReifier.java:108)
	at org.apache.camel.reifier.SagaReifier.createProcessor(SagaReifier.java:76)
	at org.apache.camel.reifier.ProcessorReifier.makeProcessorImpl(ProcessorReifier.java:574)
	at org.apache.camel.reifier.ProcessorReifier.makeProcessor(ProcessorReifier.java:540)
	at org.apache.camel.reifier.ProcessorReifier.addRoutes(ProcessorReifier.java:250)
	at org.apache.camel.reifier.RouteReifier.doCreateRoute(RouteReifier.java:377)

It looks like there is no CamelSagaService. I checked the camel-lra-starter which invokes the following

       LRASagaService service = new LRASagaService();

        Map<String, Object> parameters = new HashMap<>();
        IntrospectionSupport.getProperties(configuration, parameters, null, false);
        CamelPropertiesHelper.setCamelProperties(camelContext, service, parameters, false);

        camelContext.addService(service);

So I wonder how we can add a CamelSagaService in camel-k similarly ?

[nicolaferraro]

We should leverage the service loader mechanism available in Camel for such kind of things, I was expecting the service to be recognized automatically.

Also properties should be recognized by Camel main in order to be used in Camel K.

[zhfeng]

Thanks @nicolaferraro , so the feature has not been supported in the camel-k currently ?

[nicolaferraro]

I meant that if we fix it in Camel, we can avoid adding boilerplate in Camel K, but it should be supported.

You can bind a LRASagaService using bean binding also in Camel K.

[zhfeng]

sure, I get it.

[zhfeng]

@nicolaferraro can you review #1109 please ?

[zhfeng]

I just add the LRASagaService in the router configuration.

[lburgazzoli]

@zhfeng @apache/camel-committers should we add a saga customizer in camel-k-runtime ? or will this issue be fixed on camel side ?

[zhfeng]

@lburgazzoli I think it could be better to be fixed on the camel side if possible.

[lburgazzoli]

@zhfeng o can you open an issue on camel side and close this one ?

[zhfeng]

yeah, I will

[zhfeng]

I raise CAMEL-15164 for services recognize automatically and since the Saga examples have been merged. So I close this issue now and if the CAMEL-15164 is resolved in the future camel releases, I would like to investigate to see how we can leverage it to improve this example.