Triggering VM replacement when user_data changes

[outscale-age]

Current Terraform Version

Terraform v1.3.5

Use-cases

When using bash scripts inside VM user data, those scripts are usually only run at VM startup, and on a clean system, to make run-time tunings to the OS. When updating the user_data field, today the provider tells the user that an in-place update will take place, and implements this via a stop/update/start cycle.

This has the inconvenient of:

• Not triggering any change in the existing VMs (unless specific provision is made) - but still having them powered off/on.
• Not allowing automatic VM replacements when clean-state provisioning scripts are written.

Attempted Solutions

Work-around is manually using terraform apply -replace, and lifecycle ignores.
It seems that TF lifecycle .replace_triggered_by is not applicable to resource own attributes.

Proposal

Provide an optional setting in the resource that would alter the behavior of the user_data triggered change, letting the user choose between in-place updating (stop, start) and VM replacement.