[DPE-5711] Add warnings to destructive actions

[sinclert-canonical]

This PR adds warning level messages when a destructive action is performed. The definition of destructive seems to be associated with data loss, which I think it can only happen, from user action, whenever they force a primary failover without checking considering the health of such instance.

Additional info

• Paulo confirmed that this ticket was created to familiarised myself with the codebases.
• Alex referenced this PostgreSQL operator PR as the reason behind the need for warnings.

[taurus-forever]

Can you please explain the benefits of merging this? Warning for force action?

Can we warn it globally in a moment of setting force=True?

Up 2 Paulo and Carl.

[sinclert-canonical]

Can you please explain the benefits of merging this? Warning for force action?

I think that the upgrade action will not execute the upgrade if the unit is considered unhealthy (whatever that means). This action could be forced by using the --force flag, which, may lead to data-loss.

Can we warn it globally in a moment of setting force=True?

We could put it in the charm's _on_resume_upgrade_action method (only one that calls the Upgrade.reconcile_upgrade method with an event), but we would be raising warnings even if the upgrade is not actually executed. Do we want that?

[paulomach]

My take on this is that, having the differentiation can be useful for a post morten check if things go bad and logs where not in debug level.

[sinclert-canonical]

Added info messages to Workload._diable_router method.

[carlcsaposs-canonical]

Suggested change

	logger.warning(f"Resume upgrade action ran with {force=}")
	logger.warning(f"Resume upgrade action ran with force=True")

nit (#336 (comment))

technically end result is the same, but think we should avoid using repr syntax (e.g. for type str) when the output is intended for the user instead of developer, since repr syntax does not line up with juju cli syntax

[sinclert-canonical]

I see many usages of this syntax throughout the repo (see GitHub search). Keeping it for now.

[carlcsaposs-canonical]

those usages are when the output is intended for developer, and to show the developer what the value of a python variable is

those usages are not for displaying what the user inputs of a juju action were