If workspace base image does not have labels, skip merge of image labels

[osallou]

What does this PR do?

This PR fixes issue #7249. If image does not have labels in config, the merge fails with nullpointerexception. This patch does the merge only if labels!=null

What issues does this PR fix or reference?

With SINGLE_MODE, if image does not have any LABEL, an exception is raised when trying to merge the labels. This PR checks that LABEL is not null before merge, else skip the merge.

Release Notes

N/A

Docs PR

None, bug fix only. No impact on documentation.

[codenvy-ci]

Can one of the admins verify this patch?

[codenvy-ci]

Can one of the admins verify this patch?

[benoitf]

@osallou you'll need to sign ECA before being able to accept a PR
https://www.eclipse.org/legal/ECA.php

[benoitf]

ci-build

[osallou]

I just signed the ECA, but does not seem to be taken into account in checks...
I also updated commit to be gpg signed, but again ip-validation does not take it into account though commit details show code has been signed (by same address

[codenvy-ci]

Build # 4317 - FAILED

Please check console output at https://ci.codenvycorp.com/job/che-pullrequests-build/4317/ to view the results.

[benoitf]

ci-build

[codenvy-ci]

Build # 4318 - FAILED

Please check console output at https://ci.codenvycorp.com/job/che-pullrequests-build/4318/ to view the results.

[benoitf]

@osallou could you please run command

$ mvn com.coveo:fmt-maven-plugin:2.0.0:format

in traefik module to fix the formatting issue, thanks

also if you can add a test in https://github.com/osallou/che/blob/231cd2d44b20d3321b9d13ac9f17cd5aade1cdd7/plugins/plugin-traefik/plugin-traefik-docker/src/test/java/org/eclipse/che/plugin/traefik/TraefikCreateContainerInterceptorTest.java

with

when(imageInfoConfig.getLabels()).thenReturn(null);

[benoitf]

ci-build

[codenvy-ci]

Build success. https://ci.codenvycorp.com/job/che-pullrequests-build/4319/

[benoitf]

thanks @osallou !