Unable to Generate List Class for CRD using java-generator-maven-plugin

[fengyinqiao]

Describe the bug

Hello,

I'm using the Fabric8 Kubernetes Client (version 6.12.0) to automatically generate Java classes from a CRD. The generation process successfully creates the individual resource class (ElasticSearch.class), but it does not generate the corresponding list class (ElasticSearchList.class).

Environment

• MacOS 13.5
• Java Version: 17
• Kubernetes Version: 1.20
• Fabric8 Kubernetes Client Version: 6.12.0

Issue Description

When I run the Maven generation plugin (java-generator-maven-plugin), it only generates the ElasticSearch.class and not the ElasticSearchList.class. My Maven plugin configuration is as follows:

<!-- Maven plugin configuration here -->
<plugin>
      <groupId>io.fabric8</groupId>
      <artifactId>java-generator-maven-plugin</artifactId>
      <version>6.12.0</version>
      <executions>
	      <execution>
		      <goals>
			      <goal>generate</goal>
		      </goals>
		      <configuration>
			      <source>src/main/resources/kubernetes</source>
			      <alwaysPreserveUnknown>true</alwaysPreserveUnknown>
		      </configuration>
	      </execution>
      </executions>
</plugin>

Fabric8 Kubernetes Client version

6.12.1

Steps to reproduce

1. Configure the Maven plugin as shown above.
2. Run the Maven generation command.
3. Observe that only ElasticSearch.class is generated, not ElasticSearchList.class.

Expected behavior

generates both the ElasticSearch.class and the ElasticSearchList.class

Runtime

Kubernetes (vanilla)

Kubernetes API Server version

other (please specify in additional context)

Environment

macOS

Fabric8 Kubernetes Client Logs

No response

Additional context

No response

[manusa]

AFAIR we no longer generate Kubernetes Resource List objects.

You should reuse DefaultKubernetesResourceList-> io.fabric8.kubernetes.api.model.KubernetesList and the associated builder if needed.

/cc @shawkins @andreaTP

[fengyinqiao]

Can you give an example? @manusa thanks!

[rohanKanojia]

@fengyinqiao : Could you please check if this helps?

kubernetes-client/kubernetes-tests/src/test/java/io/fabric8/kubernetes/client/mock/CustomResourceCrudTest.java

Lines 101 to 110 in eaf7cff

	MixedOperation<CronTab, KubernetesResourceList<CronTab>, Resource<CronTab>> cronTabClient = client
	.resources(CronTab.class);
	cronTabClient.inNamespace("test-ns").create(cronTab1);
	cronTabClient.inNamespace("test-ns").create(cronTab2);
	cronTabClient.inNamespace("test-ns").create(cronTab3);
	KubernetesResourceList<CronTab> cronTabList = cronTabClient.inNamespace("test-ns").list();
	assertNotNull(cronTabList);
	assertEquals(3, cronTabList.getItems().size());

[manusa]

new KubernetesListBuilder()
  .addToItems(new ElasticSearchBuilder()
    // ....
    .build())
  .build()

KubernetesResourceList<ElasticSearch> res = client.resources(ElasticSearch.class).list();

[fengyinqiao]

@fengyinqiao : Could you please check if this helps?

kubernetes-client/kubernetes-tests/src/test/java/io/fabric8/kubernetes/client/mock/CustomResourceCrudTest.java

Lines 101 to 110 in eaf7cff

	MixedOperation<CronTab, KubernetesResourceList<CronTab>, Resource<CronTab>> cronTabClient = client
	.resources(CronTab.class);
	cronTabClient.inNamespace("test-ns").create(cronTab1);
	cronTabClient.inNamespace("test-ns").create(cronTab2);
	cronTabClient.inNamespace("test-ns").create(cronTab3);
	KubernetesResourceList<CronTab> cronTabList = cronTabClient.inNamespace("test-ns").list();
	assertNotNull(cronTabList);
	assertEquals(3, cronTabList.getItems().size());

It does help, but is cronTabClient singleton? Whether I can use it globally after initialization, whether it has a race mode that can be used concurrently? @rohanKanojia thanks!

[andreaTP]

From the java-generator I think we never generated the "Kubernetes Resource List".

This should be sufficient for all the use-cases I'm aware of: client.resources(ElasticSearch.class)

@fengyinqiao what are you trying to achieve?

[fengyinqiao]

From the java-generator I think we never generated the "Kubernetes Resource List".

This should be sufficient for all the use-cases I'm aware of: client.resources(ElasticSearch.class)

@fengyinqiao what are you trying to achieve?

I am new to fabric8-k8s-client and use client-go/controller-runtime before.

//      List<ElasticSearch> ElasticSearchs = client.resources(ElasticSearch.class, ElasticSearch List.class).inNamespace(namespace).list().getItems();
        List<ElasticSearch> ElasticSearchs = client.resources(ElasticSearch.class).inNamespace(namespace).list().getItems();

I thought there was only the first way to list CR, what‘s the difference between them? @andreaTP

[manusa]

There's no difference, the latter calls the former with a null parameter.

kubernetes-client/kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/KubernetesClient.java

Line 142 in 25ecf84

return resources(resourceType, null);

This means that the client will query the cluster to retrieve the required information such as the plural, and so on.

I'm closing this issue, since the main topic was already covered.