Add ReadOnly option to volumeMount in Pods

[irumaru]

Added ReadOnly to the volumeMount option in Pods to support mounting of ReadOnlyMany(ROX) PVC.
#279

The default is ReadOnly: false.
The reason was to avoid destructive changes, considering the possibility that some users may already be writing to the volume in the init container.

Here are the results of a simple test.
files.zip

Test Contents

• kubectl apply -f pvc.yaml to create pods to add pods and scenarios
• kubectl exec -it vp -- /bin/bash to add main.js to /mnt/vp in pods
• Create TestRun with kubectl apply -f main.yaml

result
describe-log.txt and get-log.txt are the execution results.
You can confirm that ReadOnly for k6-test-volume is true.

[yorugac]

@irumaru, sorry for the delay!
Thanks for working on this 🙌 PR LGTM: there's just a minor suggestion to improve comments. And one more thing: could you please create a folder in config/samples with code files from your archive?

[irumaru]

@yorugac , Thanks for the review.

We have made the following two corrections.

• Added config/samples/k6_v1alpha1_k6_with_readOnlyVolumeClaim.yaml.
• Added comment to pkg/types/script.go as suggested.

Please review.

[yorugac]

Thank you for the update @irumaru! 🙌

[yorugac]

For info, failing CI for Helm on PRs is a known current issue: #419