The Plan Wants to Create an Instance That Should Already Exist
The report, in their words
A routine terraform plan on the platform repository — no code change, just a rebase before some unrelated work — reports Plan: 1 to add, 0 to change, 0 to destroy. The module declares three application instances. The console shows two. Nobody remembers deleting anything and the service has been serving traffic normally all week.
Pull evidence
One item at a time, and nothing here tells you which one matters. Deciding what is worth looking at is most of the diagnosis.
The plan output
What the refresh phase did
The audit trail for that instance
Load balancer target health over the week
What the plan would actually create
The state file
The module's git history
Provider and module versions
The same module in staging
0 of 9 inspected. You are not required to open all of them — a real investigation is judged on how few you needed.
What is your diagnosis?
Commit to one. Nothing below is shown until you do.
Guessing wrong and being told exactly why is the point of this page. Reading the answer first is not practice.