doc: add Kubernetes compatibility table

[agaudreault]

Description

With the changes made in #2281, It breaks the backward compatibility to k8s 1.18. I think this field could be used to indicates that the chart now with default appVersion: 0.10.0 only works with k8s version >= 1.19.0.

Fixes #ISSUE

Checklist

• Unit tests updated
• End user documentation updated

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[agaudreault]

I signed it

[agaudreault]

/assign @Raffo

[Raffo]

/assign @stevehipwell

[stevehipwell]

@agaudreault-jive thanks for the PR and the thought you've given but the kubeVersion field in a chart is a hard limit and should only be set if the chart resources aren't compatible with older Kubernetes versions. AFAIK this chart will work fine with older Kubernetes versions assuming that the image tag is changed to use a suitable image version. My suggestion would be to update the project README with a compatibility table and then reference that from the chart README and maybe call out on the chart README the current limit and how to install on an older K8s version.

FYI the correct pattern for a release line constraint is >=x.y-0 (so for v1.19 it would be >= 1.19-0), this will work for all actual pre-releases and more importantly it will also work for distros such as EKS where suffixes like -eks-1234 are added to the versions which appear to the constraints as pre-releases.

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ Alexandre Gaudreault (da98ef8, e917ead, 18b0c46)

[stevehipwell]

@Raffo this is no longer a chart PR, so back to you. FWIW I think this change would be useful.

[Raffo]

Thank you so much, this makes totally sense.

[Raffo]

/approve
/lgtm

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[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: agaudreault-jive, Raffo

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