--- name: alibabacloud-executing-plans description: "Execute validated Terraform plans via Alibaba Cloud IaC Service. Requires explicit user confirmation before any apply operation. WHEN: execute terraform, apply infrastructure, run terraform apply, deploy infrastructure, create cloud resources, execute plan." license: MIT metadata: author: Alibaba Cloud version: "0.7.0" --- # Alibaba Cloud Executing Plans > **AUTHORITATIVE GUIDANCE — MANDATORY COMPLIANCE** > > This skill executes validated Terraform code via Alibaba Cloud IaC Service (remote execution). > It creates **real cloud resources** that cost money. Safety gates are non-negotiable. > > **ALL CLI operations MUST use MCP tool `AlibabaCloud___CallCLI`** — never use Bash to run `aliyun` commands directly. --- > **PREREQUISITE CHECK — MANDATORY** > > Before proceeding, verify BOTH prerequisites: > > 1. **Validation passed** — check `tasks/status.json` has `status: "validated"` (internal check, don't expose to user) > 2. **User explicitly confirmed** they want to execute > > If EITHER is missing, **STOP IMMEDIATELY**: > > - Not validated? → Invoke **alibabacloud:validate** first > - No user confirmation? → Ask user before proceeding --- ## Triggers Activate when: - User explicitly asks to execute/apply the Terraform plan - User confirms they want to proceed after validation passes **NEVER activate automatically.** This skill requires explicit user intent. ## Rules 1. **Single deploy approval, granted upstream** — The user authorizes deployment ONCE in `alibabacloud-validate`'s gate. Inside this skill the entire `plan → apply` chain runs automatically. Never add a second confirmation between plan and apply. 2. **Plan before apply, results always shown** — Always run terraform plan first AND surface its output to the user before apply. The user can interrupt mid-stream if the plan reveals something unexpected, but the default flow does not stop to ask. 3. **MCP only** — ALL `aliyun` CLI commands MUST go through `AlibabaCloud___CallCLI`, never through Bash 4. **Inline content** — Read .tf files locally, then pass content as string to `--code` (MCP cannot access local files) 5. **Record everything** — All outputs recorded to tasks/ 6. **Support rollback** — Provide destroy option if apply fails 7. **Poll for completion** — IaC Service is async; use sequential MCP calls to poll 8. ⚠️ **Destructive operations (destroy) require double confirmation** 9. **Persist `state_id`** — IaC Service keeps the Terraform state remotely keyed by `state_id`. This skill MUST write it back to `tasks/status.json` (under `state.state_id`) on every Plan / Apply / Destroy and MUST pass the saved value on every subsequent Day-2 call. Losing the `state_id` orphans the remote state and forces a fresh deploy (potential duplicate resources). 10. **Source-of-truth integrity** — Some failures are only discoverable at apply time (SKU offline in target AZ, zone out-of-capacity, etc.). Any spec change forced by such a failure MUST be written back to BOTH `designs/design.md` (with a Decisions Log entry) AND `designs/terraform/*.tf` BEFORE re-running plan/apply. **Never hot-patch the in-flight apply** — Day-2 iterations re-read these files and will redeploy the broken spec if it isn't fixed at the source. --- ## State Persistence (CRITICAL for Day-2) IaC Service stores each deployment's Terraform state remotely, indexed by `state_id`. This handle is the contract that lets you iterate on the same infrastructure across multiple `executing-plans` invocations: | When | Read | Write | | --- | --- | --- | | Step 1 (start) | `tasks/status.json` → `state.state_id` (may be empty on first run) | — | | Step 3 (after plan response) | — | `state.state_id`, `state.last_plan_at` | | Step 5/6 (after apply succeeds) | — | `state.state_id` (re-confirm), `state.last_apply_at` | | Destroy (after success) | — | `state.last_destroy_at`; keep `state_id` as historical record | **Branching by Day-1 vs Day-2:** | Scenario | Saved `state_id` | Plan CLI | | --- | --- | --- | | Day-1 (first run) | absent / empty | `--code '{CODE}' --client-token ` | | Day-2 (iteration) | present | `--code '{CODE}' --state-id {STATE_ID} --client-token ` | Apply always passes `--state-id`; pass `--code` too only when the HCL changed between plan and apply (rare — usually code is already final at plan time). **Legacy / migration edge case.** If status is `executed` but `state.state_id` is absent (status.json predates this schema), STOP before touching the remote — ask the user whether to: - (a) treat this as Day-1 and create a fresh state (risks duplicate resources alongside the legacy deployment), or - (b) abort and let the user supply the missing `state_id` manually (recommended if they know it). Never silently start fresh — the user paid for those resources. --- ## MCP Execution Model **CRITICAL: The `AlibabaCloud___CallCLI` MCP tool runs on a REMOTE server. It CANNOT:** - Access local files (no `file://`, no `$(cat ...)`, no local paths) - Use shell operators (`|`, `>`, `&&`, `$()`) - Use shell variables or environment variables **Therefore, you MUST:** 1. Use the `Read` tool to read `.tf` file contents into your context 2. Concatenate all `.tf` files into a single string and pass it inline via `--code` 3. Escape single quotes in HCL content (replace `'` with `'\''` if needed) 4. Generate a fresh UUID for `--client-token` on every Plan / Apply / Destroy call (idempotency key, format `[0-9a-zA-Z-]{1,64}`) --- ## Process ### Step 1: Verify Prerequisites 1. Read `tasks/status.json`: - `status` must be `"validated"` (Day-1) OR `"executed"` (Day-2 re-iteration after planning produced new code) - Capture `state.state_id` into `{STATE_ID}` (may be empty on first run — that signals Day-1) - If `status == "executed"` but `state.state_id` is missing, see the legacy edge case in [State Persistence](#state-persistence-critical-for-day-2) before proceeding 2. Read `tasks/validation-report.md` — must show all reviews PASS 3. Confirm user intent one more time, and surface whether this is Day-1 or Day-2: > "Ready to execute Terraform. > > {Day-1: This will create real cloud resources on Alibaba Cloud and incur costs.} > {Day-2: This will update the existing deployment (state `{STATE_ID}`); changes > shown in the next plan output will be applied to the live resources.} > > Proceed with `terraform plan`?" ### Step 2: Prepare Template Content **Read all `.tf` files** from the design directory and concatenate them into a single string: ``` # Use Read tool to get content of each .tf file: Read: .aliyun-ai-ops-spec/{name}/designs/terraform/main.tf Read: .aliyun-ai-ops-spec/{name}/designs/terraform/variables.tf Read: .aliyun-ai-ops-spec/{name}/designs/terraform/outputs.tf # ... any other .tf files ``` Concatenate all content into one `CODE` string. This will be passed inline via `--code` to MCP commands. ### Step 3: Execute Terraform Plan **Branch by whether `{STATE_ID}` was loaded in Step 1.** **Day-1 (no prior `state_id`):** ``` AlibabaCloud___CallCLI: command: "aliyun iacservice execute-terraform-plan --code '{CODE}' --client-token {CLIENT_TOKEN}" ``` **Day-2 (continuing on saved `state_id`):** ``` AlibabaCloud___CallCLI: command: "aliyun iacservice execute-terraform-plan --code '{CODE}' --state-id {STATE_ID} --client-token {CLIENT_TOKEN}" ``` Where: - `{CODE}` = concatenated .tf content (single quotes properly escaped) - `{CLIENT_TOKEN}` = fresh UUID (format `[0-9a-zA-Z-]{1,64}`) — required for idempotency - `{STATE_ID}` = value from `tasks/status.json` → `state.state_id` (Day-2 only) **Response contains a state file ID (typically `StateId`)** — capture it as `{STATE_ID}`. On Day-2 it will match the value passed in; on Day-1 this is the freshly minted one. **PERSIST IMMEDIATELY** — before polling, before showing the plan output to the user, silently update `tasks/status.json`: ```json { ..., "state": { "state_id": "{STATE_ID}", "last_plan_at": "{ISO timestamp}", ... } } ``` Rationale: if the user aborts at the Step 4 confirmation, the next invocation must still be able to continue on this state. **Never poll or proceed before this write completes.** **Poll for completion** (see Polling Strategy below): ``` AlibabaCloud___CallCLI: command: "aliyun iacservice get-execute-state --state-id {STATE_ID}" ``` ### Step 4: Present Plan Results (no second confirmation) Show the plan output to user, then **proceed directly to Step 5** — do NOT stop to ask "Confirm apply?". The user already authorized deployment at the validate-stage gate; a second confirmation here is friction that this skill explicitly removes. Write plan results to `tasks/tf-plan-result.md`. Display: > "Terraform plan results: > > - {N} resources to create > ~ {N} resources to modify > > - {N} resources to destroy > > {Summary of key resources} > > 即将自动进入 apply 阶段。如发现 plan 不符合预期,请立刻中断我(例如按 Esc / 中止当前消息)。" If the plan output reveals something the user clearly did not consent to (e.g. unexpected resource destruction in a Day-2 modify when no destroy was discussed), STOP and surface it as a question — this is a safety override, not the default flow: > "⚠️ plan 中检测到非预期的破坏性变更: > > - `` 将被 destroy/replace > > 这通常不在变更范围内,是否确认继续?回复 **\"继续\"** 才会 apply;回复 **\"停\"** 我立刻中止。" Default path (no anomalies): emit the display block, then immediately invoke Step 5 in the same turn. ### Step 5: Execute Terraform Apply (auto, immediately after Step 4) Reuse `{STATE_ID}` (saved in Step 3) and a **fresh** `--client-token` (different UUID from the plan call): ``` AlibabaCloud___CallCLI: command: "aliyun iacservice execute-terraform-apply --state-id {STATE_ID} --client-token {CLIENT_TOKEN}" ``` If the HCL changed after plan (rare — usually it didn't), also pass `--code '{CODE}'` (mutually included with `--state-id`). The apply response returns the same `{STATE_ID}` — re-confirm it matches the saved value before polling. If for any reason a NEW state_id appears, treat that as an anomaly: stop, alert the user, and do NOT overwrite the saved one without explicit confirmation. **Poll for completion:** ``` AlibabaCloud___CallCLI: command: "aliyun iacservice get-execute-state --state-id {STATE_ID}" ``` ### Step 6: Record Results Write results to `tasks/tf-apply-result.md`: ```markdown # Terraform Apply Results - {Requirement Name} ## Timestamp {ISO timestamp} ## State ID {state-id} ## Status SUCCESS / FAILED ## Resources Created | Resource Type | Resource Name | Resource ID | |---------------|---------------|-------------| | ... | ... | ... | ## Outputs | Name | Value | |------|-------| | ... | ... | ## Errors (if any) {error details} ``` ### Step 7: Update Internal State + TODO list 1. Silently update `tasks/status.json`. **Do NOT mention this file to the user.** ```json { ..., "status": "executed", "updated_at": "{ISO timestamp}", "state": { "state_id": "{STATE_ID}", "last_plan_at": "{from Step 3}", "last_apply_at": "{ISO timestamp of successful apply}", "last_destroy_at": null } } ``` `state.state_id` MUST be retained even on Day-2 transitions (do not clear it between iterations). Subsequent `executing-plans` invocations will read it back in Step 1 to continue on the same remote state. 2. Update the user-facing TODO list via `TodoWrite`: mark **"部署执行:terraform plan/apply via IaC Service"** → `completed`. This closes the 3-task scaffold the planning skill rendered after design confirmation, giving the user a clean "everything done" view. On apply failure or destroy: leave the task in `in_progress` so the user understands the workflow has not finished; mark `completed` only after the resource state is reconciled (retry succeeded, partial destroy completed, or user explicitly abandons). ### Step 8: Generate Deployed Topology (`topology.html`) **When:** Apply succeeded. Skip if failed or partial. **⚠️ `topology.html` ≠ `designs/architecture.html`。** `architecture.html` 是规划阶段的设计图,数据来自 design spec。`topology.html` 是部署后的实际拓扑图,数据来自 `get-execute-state` 的真实远程状态。不要复用、不要搞混。 **做法:** 1. 用 Bash 找到并读取 guide: ```bash GUIDE=$(find ~/.qoderwork/plugins-custom ~/Desktop/alibabacloud-agent-toolkit -path "*/alibabacloud-executing-plans/references/architecture-topology-html-guide.md" 2>/dev/null | head -1) cat "$GUIDE" ``` 找不到就停下告诉用户。**必须读完这个文件再动手,不准凭记忆生成。** 2. 调用 `aliyun iacservice get-execute-state --state-id {STATE_ID}` 获取真实部署状态。 3. 严格按 guide 的每一节生成 `/topology.html`,用浏览器打开验证。 --- ## Polling Strategy IaC Service operations are **asynchronous**. After submitting a job, poll using sequential MCP calls: | Parameter | Value | |-----------|-------| | First poll delay | Wait ~5 seconds (inform user "正在执行中...") then call | | Poll interval | Every 10 seconds, call `get-execute-state` again | | Max attempts | 60 attempts (≈10 minutes) | | Timeout action | Report "still running" with `{STATE_ID}` for manual check | **How to poll:** 1. Call `AlibabaCloud___CallCLI` with `get-execute-state` 2. Check `Status` in response: - `"Running"` → inform user "执行中..." and call again after brief pause - `"Succeeded"` → proceed to next step - `"Failed"` → extract `ErrorMessage`, go to Error Handling 3. Repeat until terminal state or max attempts reached **Important:** Each poll is a separate `AlibabaCloud___CallCLI` call. Do NOT use Bash loops or sleep commands. --- ## Error Handling ### Plan Fails - Record error in `tasks/tf-plan-result.md` - Identify root cause from `ErrorMessage`: | Error Code | Meaning | Action | |------------|---------|--------| | InvalidTemplate | TF syntax error | Fix TF files and re-validate | | QuotaExceeded | Resource quota limit | Inform user to request quota increase | | AccessDenied | Permission missing | Invoke `alibabacloud-ram-permission-diagnose` | | ResourceNotFound | Referenced resource missing | Check dependencies | | `Invalid*Class.Offline`, `OperationDenied.NoStock`, `Zone.NotOnSale`, etc. | Spec discovered unavailable at plan time | See [Spec-driven Failures](#spec-driven-failures-source-of-truth-recovery) below | | InternalError | Service issue | Retry once after informing user | - Set status back to "plans-written" for re-validation - **Keep `state.state_id`** in status.json if one was already saved from a prior successful run — never delete it on a plan failure. The remote state still exists and the next attempt must continue on it. ### Apply Fails - Record error in `tasks/tf-apply-result.md` - Check partial state: ``` AlibabaCloud___CallCLI: command: "aliyun iacservice get-execute-state --state-id {STATE_ID}" ``` - Classify the failure first, then offer the right options: | Failure class | Examples | Where to go | |---------------|----------|-------------| | **Spec-driven** (resource exists in API catalog but is rejected at create time) | `InvalidDBInstanceClass.Offline`, `OperationDenied.NoStock`, `Zone.NotOnSale`, instance family sold out in target AZ | [Spec-driven Failures](#spec-driven-failures-source-of-truth-recovery) — MANDATORY source-of-truth sync, do NOT hot-patch | | **Structural** (HCL refers to something that does not exist or has wrong dependencies) | Wrong VPC ID, missing security group reference, circular dependency | Fix HCL in `designs/terraform/*.tf`, re-run plan/apply (keep state_id) | | **Permission** | `AccessDenied`, `Forbidden`, `NoPermission` | Invoke `alibabacloud-spec-ops:alibabacloud-ram-permission-diagnose`; once RAM is fixed re-run apply with same state_id | | **Transient** | `ServiceUnavailable`, intermittent 5xx | Re-run apply once with same state_id | After classification, present these options to the user (in addition to the diagnosed root cause): 1. Apply the spec/HCL fix and retry apply 2. Destroy partially created resources (uses the Destroy gate below) 3. Pause for manual investigation — keep state_id so we can resume ### Spec-driven Failures (source-of-truth recovery) Some Alibaba Cloud resource constraints are only discoverable at apply time — the API lists a SKU as available but `CreateInstance` returns `InvalidDBInstanceClass.Offline`; a zone is out of capacity for a specific instance family; an EIP bandwidth-package shape is no longer sold. These are not bugs in the generated code — the design was valid when planning ran, the reality changed (or the catalog lied). **Example diagnostic (from a real session):** > ✅ 17/21 资源已创建成功(VPC, VSwitch, SG+rules, ECS, EIP+关联, OSS+ACL, RAM 全套, random_string) > ❌ RDS 实例创建失败 → 由此连带 4 个依赖(账号/库/授权/备份策略)未创建 > 根因:`mysql.n2.small.1` 在 cn-beijing-i 已下线(API 仍列出,但创建时报 `InvalidDBInstanceClass.Offline`) **Recovery flow (5 steps — every step MANDATORY):** #### 1. Diagnose From the apply error, extract: - the resource block (`.`) that failed - the failing spec value (e.g. `db_instance_class = "mysql.n2.small.1"`) - the region / zone where it failed - the upstream error code (`InvalidDBInstanceClass.Offline`, `OperationDenied.NoStock`, …) #### 2. Query live alternatives via MCP Use `AlibabaCloud___CallCLI` against the right inventory API to find currently-available specs. Pick the API by resource type: | Resource | Query CLI | | --- | --- | | RDS instance class | `aliyun rds DescribeAvailableResource --RegionId --ZoneId --Engine --EngineVersion ` | | ECS instance type | `aliyun ecs DescribeAvailableResource --RegionId --ZoneId --DestinationResource InstanceType --InstanceChargeType ` (or `DescribeRecommendInstanceType`) | | Disk category | `aliyun ecs DescribeAvailableResource --RegionId --ZoneId --DestinationResource DataDisk` | | EIP bandwidth | `aliyun vpc DescribeBandwidthPackages --RegionId ` | | (other) | Whatever `aliyun Describe*Resource` / `Describe*Availability` exists | Filter the response down to specs with **the closest match on CPU / memory / IOPS / charge type** to the failed one. Pick 1–3 candidates; mark one with ⭐ as the minimal-diff recommendation. #### 3. Ask the user (explicit, with `AskUserQuestion`) Surface diagnosis + candidates as distinct options: ``` AskUserQuestion: question: "RDS 规格 mysql.n2.small.1 在 cn-beijing-i 已下线,apply 中断。要换成下列哪个继续?" header: "替代规格" options: - label: "mysql.n2e.small.1 (推荐)" description: "n2e 新一代,同 1C2G 规格,同价位(最小改动)" - label: "mysql.x2.medium.1" description: "x2 系列,1C2G,新一代主推,价格 +12%" - label: "暂停 — 我自己来查" description: "保留已创建的 17 个资源和 state_id,稍后我手动决定后再重新触发 apply" ``` Never auto-pick a replacement, even if "obvious". Spec changes can affect cost, performance, and compliance — the user owns this call. #### 4. Sync source-of-truth (BOTH design.md AND .tf — non-negotiable) Once user confirms a replacement, **before any re-run**: 1. **`designs/design.md`**: - Update the affected resource entry with the new spec - Append to **Decisions Log** (or create the section if missing): ``` - {ISO timestamp}: RDS 实例规格 mysql.n2.small.1 → mysql.n2e.small.1 原因:原规格在 cn-beijing-i 已下线(apply 时报 InvalidDBInstanceClass.Offline) 影响:1C2G/同价位,无性能/成本变化 ``` 2. **`designs/terraform/*.tf`**: - Replace the failing field value(s); only edit the lines required - Do NOT reformat unrelated code; keep the diff minimal so the change is auditable This is Rule 10. Skipping either file silently breaks Day-2: - Skip design.md → next Day-2 planning reads stale design and "fixes" the difference back to the broken spec - Skip .tf → next plan still fails the same way #### 5. Re-run plan + apply with retained state_id The original `state_id` is already in `tasks/status.json`. Re-enter Step 3 of the main Process with the patched HCL: ``` AlibabaCloud___CallCLI: command: "aliyun iacservice execute-terraform-plan --code '{NEW_CODE}' --state-id {STATE_ID} --client-token {NEW_UUID}" ``` The 17 already-created resources stay (state remembers them); only the failed 4 + any that depend on them are created. Apply auto-flows per Rule 2. If the user picked **"暂停 — 我自己来查"** in Step 3: - Leave `status: "executing"` (do NOT roll back to `validated`) - Leave TODO task 3 `in_progress` - Tell user how to resume: "已保留 state_id `{STATE_ID}` 和已创建的 17 个资源。手动定夺规格后回到本会话回复"继续 apply",我会用更新后的 HCL 在同一 state 上 resume。" ### Destroy Operations For `terraform destroy` (cleanup or rollback): > "⚠️ **DESTRUCTIVE OPERATION** > > This will destroy ALL resources created by this Terraform configuration. > This action cannot be undone. > > Type the requirement name `{name}` to confirm destruction:" Require exact name match before proceeding. Then execute (use a fresh `--client-token`): ``` AlibabaCloud___CallCLI: command: "aliyun iacservice execute-terraform-destroy --state-id {STATE_ID} --client-token {CLIENT_TOKEN}" ``` Poll for completion using same strategy as apply. After destroy succeeds, update `tasks/status.json`: ```json { ..., "status": "destroyed", "updated_at": "{ISO timestamp}", "state": { "state_id": "{STATE_ID}", "last_plan_at": "{prior}", "last_apply_at": "{prior}", "last_destroy_at": "{ISO timestamp}" } } ``` **Keep `state.state_id` as a historical record** — do not clear it. If the user later wants to redeploy fresh (new state), planning will detect `status == "destroyed"` and prompt for net-new Day-1 vs reuse decision. --- ## IaC Service MCP Command Reference **All commands use `AlibabaCloud___CallCLI` with the full CLI string:** | Operation | MCP Command | |-----------|-------------| | Plan | `aliyun iacservice execute-terraform-plan --code '{content}' --client-token {uuid}` | | Apply | `aliyun iacservice execute-terraform-apply --state-id {id} --client-token {uuid}` | | Poll status | `aliyun iacservice get-execute-state --state-id {id}` | | Destroy | `aliyun iacservice execute-terraform-destroy --state-id {id} --client-token {uuid}` | ### Command Parameter Reference **`aliyun iacservice execute-terraform-plan`** | Param | Required | Type | Notes | | --- | --- | --- | --- | | `--client-token` | yes | string `[0-9a-zA-Z-]{1,64}` | Idempotency key, fresh UUID per call | | `--code` | conditional | string | Full Terraform HCL content (concatenated from all `.tf` files). Required for first plan; on a follow-up plan with unchanged content you may pass only `--state-id` | | `--state-id` | conditional | string | When non-empty, continue Plan on top of an existing state file | **`aliyun iacservice execute-terraform-apply`** | Param | Required | Type | Notes | | --- | --- | --- | --- | | `--client-token` | yes | string `[0-9a-zA-Z-]{1,64}` | Idempotency key, fresh UUID per call | | `--code` | conditional | string | Required only if HCL changed since plan; pass the new concatenated content | | `--state-id` | conditional | string | State ID from the preceding plan; pass it when content is unchanged so Apply continues on the same state | **`aliyun iacservice execute-terraform-destroy`** | Param | Required | Type | Notes | | --- | --- | --- | --- | | `--client-token` | yes | string `[0-9a-zA-Z-]{1,64}` | Idempotency key, fresh UUID per call | | `--state-id` | yes | string | State ID of the deployment to tear down | **`aliyun iacservice get-execute-state`** | Param | Required | Type | Notes | | --- | --- | --- | --- | | `--state-id` | yes | string | State ID returned by the preceding Plan / Apply / Destroy call | **⚠️ NEVER:** - Use `file://` paths (MCP cannot access local filesystem) - Use `$(cat ...)` shell substitution (MCP doesn't support shell operators) - Use Bash tool to run `aliyun` commands (always use MCP) - Pass `--region` — IaC Service derives the region from the HCL `provider "alicloud"` block; the CLI does not accept a `--region` flag here - Omit `--client-token` from Plan / Apply / Destroy — it is required for idempotency - Use `--execution-id` or `--template-body` — these are stale names from earlier drafts; the correct parameters are `--state-id` and `--code` --- ## Safety Principles - **Never skip plan** — Always plan before apply, and always show plan output to the user - **Auto-apply is the default flow** — The deploy authorization is granted ONCE at the validate-stage gate; do NOT add a second confirmation between plan and apply. The user can still interrupt mid-stream; the safety override in Step 4 covers unexpected destructive changes. - **Never silent destroy** — Destroy (Rule 8) requires explicit naming confirmation; this is independent of the plan→apply auto-flow - **Always use MCP** — Never run aliyun CLI via Bash; always via `AlibabaCloud___CallCLI` - **Always inline content** — Read files first, pass content as string to MCP - **Always record** — Every operation logged to tasks/ - **Always poll** — Don't assume completion; verify state via MCP - **Always persist `state_id`** — Write to `tasks/status.json` → `state.state_id` immediately after every plan response; never proceed without saving - **Never orphan remote state** — Keep `state.state_id` across re-iterations and even after destroy (historical record); only the user may decide to discard it - **Fail safe** — On error, stop and inform user; don't retry blindly