Defining namespace explicitly is required after Spring Boot upgrade for leader election

[johanhaleby]

We're using the leader election library (org.springframework.cloud:spring-cloud-kubernetes-fabric8-leader:3.1.2) but after upgrading from Spring Boot 3.2.6 to 3.3.0 we ran into this issue:

2024-06-12T05:44:19.774Z ERROR 1 --- [my-service] [           main] o.s.boot.SpringApplication               : Application run failed
[my-service-7bd888c6f7-w8js9]
org.springframework.context.ApplicationContextException: Failed to start bean 'leaderInitiator'
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:291)
	at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:471)
	at java.base/java.lang.Iterable.forEach(Unknown Source)
	at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:260)
	at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:205)
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:981)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:627)
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:66)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:335)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1363)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1352)
	at com.mycompany.BootstrapKt.main(Bootstrap.kt:19)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:91)
	at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:53)
	at org.springframework.boot.loader.launch.JarLauncher.main(JarLauncher.java:58)
Caused by: io.fabric8.kubernetes.client.KubernetesClientException: namespace cannot be null
	at io.fabric8.kubernetes.client.dsl.internal.BaseOperation.inNamespace(BaseOperation.java:252)
	at io.fabric8.kubernetes.client.dsl.internal.BaseOperation.inNamespace(BaseOperation.java:97)
	at org.springframework.cloud.kubernetes.fabric8.leader.Fabric8LeaderRecordWatcher.lambda$start$1(Fabric8LeaderRecordWatcher.java:63)
	at org.springframework.cloud.kubernetes.commons.leader.LeaderUtils.guarded(LeaderUtils.java:51)
	at org.springframework.cloud.kubernetes.fabric8.leader.Fabric8LeaderRecordWatcher.start(Fabric8LeaderRecordWatcher.java:59)
	at org.springframework.cloud.kubernetes.commons.leader.LeaderInitiator.start(LeaderInitiator.java:62)
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:288)
	... 18 common frames omitted

What I had to do was to explicitly add the namespace property to the config:

spring:
  cloud:
    kubernetes:
      leader:
        namespace: default
        config-map-name: leader

I.e. it seems like the spring.cloud.kubernetes.leader.namespace property is now also a required property besides spring.cloud.kubernetes.leader.config-map-name. This is not clear in the documentation. I suspect that either this is a bug in the code or that something should be added to the documentation.

[wind57]

Duplicate of : #1661

[johanhaleby]

@wind57 You're right, missed it! Thanks.