How to intercept message republished to DLQ in Spring Cloud RabbitMQ? - spring-boot

Question

I want to intercept messages that are republished to DLQ after retry limit is exhausted, and my ultimate goal is to eliminate x-exception-stacktrace header from those messages.
Config:
spring:
application:
name: sandbox
cloud:
function:
definition: rabbitTest1Input
stream:
binders:
rabbitTestBinder1:
type: rabbit
environment:
spring:
rabbitmq:
addresses: localhost:55015
username: guest
password: guest
virtual-host: test
bindings:
rabbitTest1Input-in-0:
binder: rabbitTestBinder1
consumer:
max-attempts: 3
destination: ex1
group: q1
rabbit:
bindings:
rabbitTest1Input-in-0:
consumer:
autoBindDlq: true
bind-queue: true
binding-routing-key: q1key
deadLetterExchange: ex1-DLX
dlqDeadLetterExchange: ex1
dlqDeadLetterRoutingKey: q1key_dlq
dlqTtl: 180000
prefetch: 5
queue-name-group-only: true
republishToDlq: true
requeueRejected: false
ttl: 86400000
#Configuration
class ConsumerConfig {
companion object : KLogging()
#Bean
fun rabbitTest1Input(): Consumer<Message<String>> {
return Consumer {
logger.info("Received from test1 queue: ${it.payload}")
throw AmqpRejectAndDontRequeueException("FAILED") // force republishing to DLQ after N retries
}
}
}
First I tried to register #GlobalChannelInterceptor (like here), but since RabbitMessageChannelBinder uses its own private RabbitTemplate instance (not autowired) for republishing (see #getErrorMessageHandler) it doesn't get intercepted.
Then I tried to extend RabbitMessageChannelBinder class by throwing away the code related to x-exception-stacktrace and then declare this extension as a bean:
/**
* Forked from {#link org.springframework.cloud.stream.binder.rabbit.RabbitMessageChannelBinder} with the goal
* to eliminate {#link RepublishMessageRecoverer.X_EXCEPTION_STACKTRACE} header from messages republished to DLQ
*/
class RabbitMessageChannelBinderWithNoStacktraceRepublished
: RabbitMessageChannelBinder(...)
// and then
#Configuration
#Import(
RabbitAutoConfiguration::class,
RabbitServiceAutoConfiguration::class,
RabbitMessageChannelBinderConfiguration::class,
PropertyPlaceholderAutoConfiguration::class,
)
#EnableConfigurationProperties(
RabbitProperties::class,
RabbitBinderConfigurationProperties::class,
RabbitExtendedBindingProperties::class
)
class RabbitConfig {
#Bean
#Primary
#Role(BeanDefinition.ROLE_INFRASTRUCTURE)
#Order(Ordered.HIGHEST_PRECEDENCE)
fun customRabbitMessageChannelBinder(
appCtx: ConfigurableApplicationContext,
... // required injections
): RabbitMessageChannelBinder {
// remove the original (auto-configured) bean. Explanation is after the code snippet
val registry = appCtx.autowireCapableBeanFactory as BeanDefinitionRegistry
registry.removeBeanDefinition("rabbitMessageChannelBinder")
// ... and replace it with custom binder. It's initialized absolutely the same way as original bean, but is of forked class
return RabbitMessageChannelBinderWithNoStacktraceRepublished(...)
}
}
But in this case my channel binder doesn't respect the YAML properties (e.g. addresses: localhost:55015) and uses default values (e.g. localhost:5672)
INFO o.s.a.r.c.CachingConnectionFactory - Attempting to connect to: [localhost:5672]
INFO o.s.a.r.l.SimpleMessageListenerContainer - Broker not available; cannot force queue declarations during start: java.net.ConnectException: Connection refused
On the other hand if I don't remove original binder from Spring context I get following error:
Caused by: java.lang.IllegalStateException: Multiple binders are available, however neither default nor per-destination binder name is provided. Available binders are [rabbitMessageChannelBinder, customRabbitMessageChannelBinder]
at org.springframework.cloud.stream.binder.DefaultBinderFactory.getBinder(DefaultBinderFactory.java:145)
Could anyone give me a hint how to solve this problem?
P.S. I use Spring Cloud Stream 3.1.6 and Spring Boot 2.6.6

Answer 1

Disable the binder retry/DLQ configuration (maxAttempts=1, republishToDlq=false, and other dlq related properties).
Add a ListenerContainerCustomizer to add a custom retry advice to the advice chain, with a customized dead letter publishing recoverer.
Manually provision the DLQ using a Queue #Bean.
#SpringBootApplication
public class So72871662Application {
public static void main(String[] args) {
SpringApplication.run(So72871662Application.class, args);
}
#Bean
public Consumer<String> input() {
return str -> {
System.out.println();
throw new RuntimeException("test");
};
}
#Bean
ListenerContainerCustomizer<MessageListenerContainer> customizer(RetryOperationsInterceptor retry) {
return (cont, dest, grp) -> {
((AbstractMessageListenerContainer) cont).setAdviceChain(retry);
};
}
#Bean
RetryOperationsInterceptor interceptor(MessageRecoverer recoverer) {
return RetryInterceptorBuilder.stateless()
.maxAttempts(3)
.backOffOptions(3_000L, 2.0, 10_000L)
.recoverer(recoverer)
.build();
}
#Bean
MessageRecoverer recoverer(RabbitTemplate template) {
return new RepublishMessageRecoverer(template, "DLX", "errors") {
#Override
protected void doSend(#Nullable
String exchange, String routingKey, Message message) {
message.getMessageProperties().getHeaders().remove(RepublishMessageRecoverer.X_EXCEPTION_STACKTRACE);
super.doSend(exchange, routingKey, message);
}
};
}
#Bean
FanoutExchange dlx() {
return new FanoutExchange("DLX");
}
#Bean
Queue dlq() {
return new Queue("errors");
}
#Bean
Binding dlqb() {
return BindingBuilder.bind(dlq()).to(dlx());
}
}