Add option to reload kubeconfig

[maboehm]

In our project we use gardener, which has a CLI gardenctl that allows targeting different clusters. Under the hood, this updates the $KUBECONFIG and replaces it with a config for the newly targeted cluster. I would love to author a plugin, that easily allows switching clusters with this from within sofka.

However, currently, this is a bit clunky. The plugin can change the kubeconfig, but at first, nothing happens. Users need to open the :ctx view (which apparently refreshes the loaded kubeconfig) and then can select the updated context. I can think of two options to improve this:

1. (optionally) detect KUBECONFIG changes automatically - this can be dangerous, so it should probably be off by default. Even when a change is detected, the user should probably be prompted if they want to actually reload (could be incoporated to the context switcher dialog (:ctx). OR
2. Allow plugins to signal that the kubeconfig should be reloaded (or that the context switcher dialog should be opened).

[nklmilojevic]

Agreed. We will add general support in sofka for a plugin to request a kubeconfig reload and open the context selector after a successful run. The user will select the context; sofka will not switch clusters automatically.

The gardenctl integration belongs in sofka-plugins. You can start creating that plugin as soon as this core support is ready. I will create a linked issue and start work on it.

[nklmilojevic]

Tracked in #669. Work has started. The planned interface is an optional action in a successful plugin report: "action": "reload-kubeconfig". I will confirm the release version when the support is ready.

[nklmilojevic]

@maboehm out in 0.28.4, so you can start submitting the PR to sofka-plugins :)