Expected a single document in the stream

[ParriePierre]

Describe the bug

Hello,

Kubernetes-client cannot read documents that contains one ressource and end with "---", snakeyaml throws exception "expected a single document in the stream".
It used to work with kubernetes-client 4.13.3.

Using Kubernetes-client:4.13.0, this used to work.

Fabric8 Kubernetes Client version

5.10.1@latest

Steps to reproduce

Using example LoadMultipleDocumentsFromFileExample, modify the file multiple-document-template.yml to keep only one resource and ending the file with "---" :

apiVersion: v1
kind: Service
metadata:
  name: redis-master
  labels:
    app: redis
    tier: backend
    role: master
spec:
  ports:
  - port: 6379
    targetPort: 6379
  selector:
    app: redis
    tier: backend
    role: master
---

snakeyaml throws exception

expected a single document in the stream
 in 'reader', line 17, column 1:
    apiVersion: v1
    ^
but found another document
 in 'reader', line 33, column 1:
    ---
    ^

	at org.yaml.snakeyaml.composer.Composer.getSingleNode(Composer.java:114)
	at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:139)
	at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:524)
	at org.yaml.snakeyaml.Yaml.load(Yaml.java:452)
	at io.fabric8.kubernetes.client.utils.Serialization.unmarshalYaml(Serialization.java:369)
	at io.fabric8.kubernetes.client.utils.Serialization.unmarshal(Serialization.java:191)
	at io.fabric8.kubernetes.client.utils.Serialization.unmarshal(Serialization.java:156)
	at io.fabric8.kubernetes.client.dsl.internal.NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.getItems(NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.java:81)
	at io.fabric8.kubernetes.client.dsl.internal.NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.getOperations(NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.java:92)
	at io.fabric8.kubernetes.client.dsl.internal.NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.accept(NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.java:215)
	at io.fabric8.kubernetes.client.dsl.internal.NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.accept(NamespaceVisitFromServerGetWatchDeleteRecreateWaitApplicableListImpl.java:53)
	at com.dassault_systemes.infra.cloud.kubernetes.driver.action.LoadMultipleDocumentsFromFileExampleTest.test(LoadMultipleDocumentsFromFileExampleTest.java:49)

Expected behavior

Kubernetes-client should be able to serialize YAML files that have only one resource and ends with "---".

Runtime

other (please specify in additional context)

Kubernetes API Server version

other (please specify in additional context)

Environment

Linux

Fabric8 Kubernetes Client Logs

No response

Additional context

Issue is not related to K8S API.

[rohanKanojia]

I can reproduce this issue. While processing YAML document, I can see YAML document is parsed correctly; however, since it's just one document this condition is not satisfied:

kubernetes-client/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/utils/Serialization.java

Lines 325 to 329 in ef50b90

	static boolean containsMultipleDocuments(String specFile) {
	final long validDocumentCount = splitSpecFile(specFile).stream().filter(Serialization::validate)
	.count();
	return validDocumentCount > 1;
	}

This behavior seems to be correct. Since it's only a single document control goes to Single document unmarshal method. But at this point there is still --- present in YAML document which causes the error.

kubernetes-client/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/utils/Serialization.java

Lines 153 to 156 in ef50b90

	if (containsMultipleDocuments(specFile)) {
	return (T) getKubernetesResourceList(parameters, specFile);
	}
	return unmarshal(new ByteArrayInputStream(specFile.getBytes()), JSON_MAPPER, parameters);

Removing leading/trailing Document delimiters --- should fix this issue.

[ParriePierre]

Thank you very much @rohanKanojia !

[rohanKanojia]

@ParriePierre : Np, Would appreciate if you could also review my PR :-)