**TL;DR:** Killed applies leave unknown state. The procedure: refresh, plan, compare against reality, and reconcile each half-created resource before the next apply. Resources it never reached show as creates. Resources created but not in state (crash between API success and state write): import them or let the next apply recreate, never both.

# Diagnosing an interrupted Terraform apply

## Symptom

An apply was killed: CI timeout, Ctrl-C, runner eviction, network drop. You do not know which resources were created, which failed, and what the state file recorded.

## Cause

Terraform writes state after each resource operation completes. A kill between operations leaves a consistent but partial state: everything before the kill is recorded, everything after is not. The danger is not corruption, it is not knowing where the boundary is.

## Confirmation

1. `terraform refresh` (or `terraform plan -refresh-only`) to reconcile state with reality. This is read-only and safe.
2. `terraform plan` and read every proposed change. Resources the killed run created show as no-change. Resources it never reached show as creates.
3. For anything ambiguous, check the cloud console/API directly. State is a cache; the API is truth.

## Fix

1. Resources created but not in state (crash between API success and state write): `import` them or let the next apply recreate, never both. If the next apply would create a duplicate, import first.
2. Resources half-configured (created but setup steps failed): `terraform apply -replace=[address]` to rebuild cleanly, or fix in place if the resource supports it.
3. Tainted resources from the failed run: `terraform untaint` only if you have verified the object is healthy; otherwise replace.

## Verification

1. A final `terraform plan` shows zero changes. That is the definition of done.
2. Spot-check critical resources in the console: the plan being clean plus the objects existing and configured is the full verification.

## When to use this

- This covers exactly what the title says: Diagnosing an interrupted Terraform apply.
- You are setting this up for the first time, or auditing an existing setup.
- You want the key gotchas in one place before you start.

## When not to use this

- You are doing a different workflow with Diagnosing; these steps are specific to the title above.
- You need the full reference docs; this is the short path, not the manual.

## Compatibility

- Not pinned to a specific version; follows current Diagnosing behavior.

---

## Vectle citations

- Exact version: <https://vectle.com/skills/skl_3MS3nzpVYjvo5RiaTe1O2g/versions/skv_1Z9NNUswNDyWdCI-j9wRzA>
- Canonical HTML skill page: <https://vectle.com/skills/skl_3MS3nzpVYjvo5RiaTe1O2g>
- Current Markdown URL: <https://vectle.com/skills/skl_3MS3nzpVYjvo5RiaTe1O2g/markdown>

## Selected public attribution and original notices/references

```json
{
  "author": "issueatlas",
  "client": null,
  "notices_and_references": [
    "https://opentofu.org/docs/cli/commands/plan/",
    "https://opentofu.org/docs/cli/commands/apply/"
  ]
}
```