azure-eventhub-demo

This is a working spring boot application which sends and receives messages to and from Azure Event Hub using spring-cloud-azure-eventhubs-stream-binder.

There is a spring boot test which accesses an event hub inside the azure cloud. This is, because there is no local replacement like testcontainers or a docker image for Event Hubs.

Conflicting dependency versions from azure sdk for java

This project also demonstrates, that the following azure dependency versions are incompatible:

• com.microsoft.azure:spring-cloud-azure-appconfiguration-config-web:1.2.7
• com.microsoft.azure:spring-cloud-azure-feature-management-web:1.2.7
• com.microsoft.azure:spring-cloud-azure-eventhubs-stream-binder:1.2.8

If all three depencencies are used with the same version 1.2.7, all works fine. If the eventhub dependency is upgraded to 1.2.8, this leads to the following exception during exception:

Caused by: java.lang.NoSuchMethodError: 'void com.azure.core.util.logging.ClientLogger.warning(java.lang.String)'
   at com.azure.core.amqp.implementation.AmqpChannelProcessor.onSubscribe(AmqpChannelProcessor.java:69) ~[azure-core-amqp-1.3.0.jar:na]
   at reactor.core.publisher.Operators.reportThrowInSubscribe(Operators.java:224) ~[reactor-core-3.3.12.RELEASE.jar:3.3.12.RELEASE]
   at reactor.core.publisher.Flux.subscribe(Flux.java:8360) ~[reactor-core-3.3.12.RELEASE.jar:3.3.12.RELEASE]

The updated eventhub library uses the ClientLogger.warning(String) method without varargs introduced in com.azure:azure-core:1.4.0 with this commit: https://github.com/Azure/azure-sdk-for-java/commit/8e59d0aada39a3e6d166f367ca53e0de03ef91d4

The question is: how should dependencies be declared to get consistent versions. Just using the same release for all dependencies does not work, if in this case the spring-cloud-azure-eventhubs-stream-binder:1.2.8 is needed, because there is no 1.2.8 release e.g. for com.microsoft.azure:spring-cloud-azure-feature-management-web.

Needed cloud resources to get a working setup.

The test class EventHubTest needs the following Azure cloud resources, which are available within a free subscription:

• Event Hub Namespace
• Event Hub Instance
• Storage Account
• empty App Configuration

The setup process is described in this article: https://docs.microsoft.com/de-de/azure/developer/java/spring-framework/configure-spring-cloud-stream-binder-java-app-azure-event-hub

Depending on the properties of the cloud resources, the entries in application.properties and bootstrap.properties need to be updated. The files commited here do NOT contain the original connection strings.

Analyze dependency changes

The complete list of all azure dependencies which get into the service can be displayed using the following command:

mvn dependency:list | grep " -- " | cut -c 11- | sort -u | grep azure

Changing the dependency version of spring-cloud-azure-eventhubs-stream-binder from 1.2.7 to 1.2.8 results in several changed transitive dependencies as seen in the files dependencies.ok and dependencies.conflict