Make it hard to accidentally enable an experimental feature flag

[mkuratczyk]

Currently it's easy to enable an experimental feature flag like khepri_db by accident. Given the operation is irreversible, this leads to serious consequences when done in a production environment.

This PR implements the following changes:

• Management UI
  • Split the feature flags page into two tables - first with all but experimental feature flags, the second with only the experimental flags (and a warning)
  • To enable an experimental feature flag, a checkbox needs to be toggled first
• CLI
  • rabbitmqctl enable_feature_flag khepri_db won't work unless a new flag --experimental is provided

[dumbbell]

What about naming the CLI flag --experimental to make sure the user knows it’s an experimental feature flag?

Also, I feel that --force is too generic and could mean many things. I could interpret it as "I want this feature flag to be enabled even if some nodes are not running in the cluster" (which is denied today for instance).

[michaelklishin]

I agree with @dumbbell and would use --experimental instead of --force.

[michaelklishin]

The forced push was a rebase.

[mkuratczyk]

I've renamed the flag and slightly changed the error message (+rebase)

[mkuratczyk]

Thanks for the feedback, I've pushed another commit fixing all the issues you pointed out. One question that came to mind is what should happen when rabbitmqctl enable_feature_flag --experimental all is invoked. Currently it still won't enable experimental flags and while intuitively, it should, given the goal of this PR is to prevent accidental enablement of experimental features, I feel like ignoring --experimental when all is used is fine. I can easily be persuaded though. Thoughts?

[dumbbell]

Instead of ignoring, I think we should either do what it says (enable everithing including experimental feature flags), or reject the command with an error.

As you said, given the goal, I would problably reject the command because the risks will be very specific to each experimental feature flag.

[mkuratczyk]

--experimental is now rejected when all flags are to be enabled. Commit message improved

[michaelklishin]

The forced push was a rebase.

[michaelklishin]

AWS peer discovery tests occasionally fail for branches and then succeed once merged :(