Improve test coverage of Kubernetes package

[ebaron]

This PR adds several tests for deployments_kubeclient.go, focusing on the API methods used by "deployments" controller. The new tests use JSON files as input containing mock Kubernetes/OpenShift resources. Likewise, existing communication with the OpenShift API server in deployments_kubeclient.go using YAML has been changed to JSON.

This PR also fixes a bug discovered during testing, where the pod list is incorrect due to using a pointer to a loop iteration variable. This has been changed to point to elements from the slice returned by Kubernetes. This bug was introduced recently when switching from the "apps" to "deployments" API.

One other thing changed by this PR is to return an empty array for pod statuses, when there are no pods in a deployment. In order to return an empty array in the JSON response, I had to specify the "pods" attribute as "Required" in the goa design. Previously, we would return a dummy entry of "0 Running".

[fabric8cd]

@ebaron snapshot fabric8-wit image is available for testing. docker pull docker.io/fabric8/fabric8-wit:SNAPSHOT-PR-1894-1

[codecov-io]

Codecov Report

Merging #1894 into master will increase coverage by 2.39%.
The diff coverage is 31.38%.

@@            Coverage Diff             @@
##           master    #1894      +/-   ##
==========================================
+ Coverage   61.05%   63.44%   +2.39%     
==========================================
  Files         144      144              
  Lines       13366    13392      +26     
==========================================
+ Hits         8161     8497     +336     
+ Misses       4482     4084     -398     
- Partials      723      811      +88

Impacted Files	Coverage Δ
kubernetes/deployments_kubeclient.go	52.07% <31.38%> (+38.2%)	⬆️
remoteworkitem/jira.go	75% <0%> (-25%)	⬇️
remoteworkitem/scheduler.go	53.65% <0%> (-7.32%)	⬇️

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[xcoulon]

this looks good overall, but have you considered using something like go-vcr to handle the HTTP responses ? This would require you to configure/replace the default HTTP client's transport of the Kube/OS client with the one provided by the recorder, but then you may have less boilerplate code in your tests.

[ebaron]

@xcoulon go-vcr sounds promising. Could I consider that as a future enhancement, since it would involve substantial changes?

[fabric8cd]

@ebaron snapshot fabric8-wit image is available for testing. docker pull docker.io/fabric8/fabric8-wit:SNAPSHOT-PR-1894-2

[fabric8cd]

@ebaron snapshot fabric8-wit image is available for testing. docker pull docker.io/fabric8/fabric8-wit:SNAPSHOT-PR-1894-3

[ebaron]

@xcoulon Sorry about the broken rebase, this happened due to moving from the old "apps" API to "deployments" during development. I've squashed the commits and all seems good now.

[xcoulon]

@ebaron ok, I'm fine with using go-vcr later if you prefer... but please give it a try at least on 1 test to see if it helps reducing the amount of .go code.

[xcoulon]

PR approved

[fabric8cd]

@ebaron snapshot fabric8-wit image is available for testing. docker pull docker.io/fabric8/fabric8-wit:SNAPSHOT-PR-1894-4

[ebaron]

@xcoulon I'll try to experiment using go-vcr shortly. I filed an issue here: openshiftio/openshift.io#2355
Thanks for approving in the meantime.

[fabric8cd]

@ebaron snapshot fabric8-wit image is available for testing. docker pull docker.io/fabric8/fabric8-wit:SNAPSHOT-PR-1894-5

[fabric8cd]

@ebaron snapshot fabric8-wit image is available for testing. docker pull docker.io/fabric8/fabric8-wit:SNAPSHOT-PR-1894-6