configMapGenerator should accept existing ConfigMap as input

[siom79]

Eschewed features

• [X] This issue is not requesting templating, unstuctured edits, build-time side-effects from args or env vars, or any other eschewed feature.

What would you like to have added?

The configMapGenerator appends to the name of the generated ConfigMap a hash value that allows restarting the containers that actually use this ConfigMap when used together with GitOps tools like ArgoCD.

Why is this needed?

Enhance the existing functionality of the configMapGenerator such that it additionally accepts an existing ConfigMap.``

Can you accomplish the motivating task without this feature, and if so, how?

Currently properties files and env files are supported but not existing ConfigMaps.

In my setup I have a large existing ConfigMap that I do not want to convert into a properties or env file, but I want that the configMapGenerator appends the hash.

What other solutions have you considered?

Converting the large ConfigMap into properties files. :wea

Anything else we should know?

No response

Feature ownership

• [ ] I am interested in contributing this feature myself! 🎉

[k8s-ci-robot]

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