NPE when getting version when there is no build date

[yevgenykuz]

The fetchVersion() method will fail with NPE when the API server doesn't return the build date.

kubernetes-client/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/ClusterOperationsImpl.java

Line 44 in 74cc63d

public VersionInfo fetchVersion() {

It happens because SimpleDateFormat can't parse null values.

A possible fix can be null checking before calling buildWithDate:

kubernetes-client/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/ClusterOperationsImpl.java

Line 66 in 74cc63d

return new VersionInfo.Builder().withBuildDate(responseAsMap.get(VersionInfo.VersionKeys.BUILD_DATE))

Or within the buildWithDate function itself if a default value should be provided:

kubernetes-client/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/VersionInfo.java

Line 104 in 74cc63d

public Builder withBuildDate(String buildDate) throws ParseException {

This can be reproduced if k8s is mocked with the provided server in CRUD mode - https://github.com/fabric8io/kubernetes-client#crud-mode

[rohanKanojia]

@yevgenykuz : Thanks for reporting this! Would appreciate it if you could create a PR. What default value do you think we'll provide?

[yevgenykuz]

NP Ill open a PR later this week.
Not sure about the default value, i'd write "N/A" but it requires changing the type to String. I prefer to change as little as possible since i didn't go over the code to see what else may be affected.