Documentation for Installation und Maintenance of Testkube via GitOps and ArgoCD

[frederikb]

Describe the enhancement you'd like to see
I would like to see a definitive guide or at least a set of recommendations on how to install and maintain a Testkube installation via Gitops using ArgoCD.

Specifically,

• what to configure on initial installation
• what to take into consideration when performing upgrades (as in, committing the updated charts and value files in the GitOps repositories used by ArgoCD).

Additional context
The only ArgoCD specific guides are only related to automatically creating test CR . The installation guide itself only demonstrates a normal installation via Helm (imperatively via CLI).

Based on some snippets of documentation as well as various GitHub issues I presume that some specific configuration is recommended and/or some issues may have to be mitigated:

• setting useArgoCDSync to true (does this handle all cronjobs created by the operator?)
• Make it possible to pass in labels and annotations that the operator will apply to all dynamically created objects (via the Go templates). #695 suggests that we would need to configure a custom job template for each test CR
• Wrong placement of the CRDs in the operator chart #627 hints at issues on upgrades of CRDs when using ArgoCD
• The helm charts uses Helm hooks which are partly supported/translated by the Helm support of ArgoCD - is the Testkube usage fully covered?

[vsukhin]

thank you @frederikb we will think about it. for @TheBrunoLopes to review