fix(ci): key rollback-aws-fargate on the Fargate Terraform state

[cristim]

Closes #1811

rollback.yml's rollback-aws-fargate built its Terraform backend key from the Lambda state namespace, github-<env>/terraform.tfstate, and then applied -var="compute_platform=fargate" into it. Every other Fargate writer uses github-fargate-<env>/, and rollback-aws-lambda uses the bare key correctly, so the two rollback jobs were writing the same state object. Against a populated Lambda state, a Fargate rollback is a platform swap of the live Lambda stack recorded in the wrong state file, while the real Fargate state is left describing resources nobody reconciles.

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⚠️ Open item for a human with AWS access, before merge

This PR repoints a Terraform state key. That is only safe if no Fargate rollback ever wrote Fargate resources into the Lambda state. If one did, repointing strands them and they need terraform state mv or an import rather than a silent repoint.

My evidence that it is safe is indirect, and I want that stated plainly rather than buried:

• rollback.yml has never been dispatched. gh run list --repo LeanerCloud/CUDly --workflow rollback.yml --limit 30 returns [], and so does the display-name form (--workflow "Rollback Deployment").
• I validated that empty result in the other direction, because on its own it is worthless: a wrong filter and a workflow that never ran produce byte-identical output. The same query shape against ci.yml returns rows, and gh workflow list --all shows the workflow registered and active (id 292184146). So [] means "no runs", not "wrong filter".

What that does not cover:

1. A terraform apply someone ran by hand from a laptop against github-<env>/terraform.tfstate with -var="compute_platform=fargate". Nothing in the repo would record that.
2. A dispatch old enough to have aged out of the Actions API.
3. I did not look in S3. I have no AWS credentials and did not run terraform init against a real backend.

The definitive check is two read-only commands, from someone holding the deploy role:

aws s3api head-object --bucket <backend-bucket> --key "github-<env>/terraform.tfstate"
aws s3api list-object-versions --bucket <backend-bucket> --prefix "github-<env>/terraform.tfstate"

If the current version predates every Fargate-flavoured change and no version exists that a Fargate rollback could have written, the conclusion holds from the artifact rather than from run history. Until then, please read this as latent-by-inference, not as confirmed clean.

Second, smaller behaviour note for the same reviewer: after this change the Fargate rollback initialises against github-fargate-<env>/. If an environment has never had a Fargate deploy, that object does not exist and the rollback will initialise an empty state and try to create the whole stack. That is arguably the honest failure (the job is now truthful about which stack it manages), but it is a behaviour change for dev and prod, where I cannot see whether a Fargate deploy has ever run. The same S3 read answers it.

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Enumeration: every writer checked, not just the one that was broken

I did not trust the table in the issue. I swept all 17 files in .github/workflows/ for key = "github-, for -var="compute_platform=, and for group: under concurrency:, then cross-read every hit, in both directions: every Fargate writer using the fargate-prefixed key, and every Lambda writer using the bare key. scripts/ and tests/ were swept too. deploy-all.yml dispatches reusable workflows only and holds no backend key.

file	job	backend key	platform applied	concurrency group	verdict
deploy-aws-fargate.yml	deploy	github-fargate-<env>/terraform.tfstate	fargate	aws-fargate-tfstate-<env>	correct
deploy-aws-lambda.yml	build-and-deploy	github-<env>/terraform.tfstate	lambda	aws-tfstate-<env>	correct
cleanup-staging.yml	destroy-aws-fargate	github-fargate-staging/terraform.tfstate	fargate	aws-fargate-tfstate-staging	correct
cleanup-staging.yml	destroy-aws-lambda	github-staging/terraform.tfstate	lambda	aws-tfstate-staging	correct
destroy-fargate-dev.yml	destroy	github-fargate-dev/terraform.tfstate	fargate	aws-fargate-tfstate-dev	correct
rollback.yml	rollback-aws-lambda	github-<env>/terraform.tfstate	lambda	aws-tfstate-<env>	correct
rollback.yml	rollback-aws-fargate	github-<env>/terraform.tfstate	fargate	aws-tfstate-<env>	the defect

The issue's list was complete: exactly one defective site, no sibling. I looked specifically for the recurrence shape of #1592 then #1820 then #1821, where a guard landed on one resource or one workflow and not its sibling, and did not find one. That is a negative finding, so the guard below is what makes it durable, rather than my having read carefully once. Reading carefully does not survive the next edit.

Adjacent sites checked and cleared, with the reason each is not an instance:

• deploy-aws-fargate.yml "Clear stale state lock" step: a second github-fargate-<env>/ key plus a .tflock path, no platform var. Correct namespace, no pairing to get wrong.
• Azure (deploy-azure.yml, cleanup-staging.yml:destroy-azure, rollback.yml:rollback-azure): writes github-<env>.terraform.tfstate, a single blob namespace with no platform split. No workflow passes compute_platform for Azure; it comes from github-<env>.tfvars.
• GCP (deploy-gcp.yml, cleanup-staging.yml:destroy-gcp, rollback.yml:rollback-gcp): uses prefix = "github-<env>", a different backend keyword entirely.
• scripts/init-backend.sh:222: emits key = "${ENVIRONMENT}/terraform.tfstate" into a generated template, not github--prefixed and with no platform.
• No file under scripts/ pairs a backend key with a compute_platform today.

The change

.github/workflows/rollback.yml

1. Backend key github-%s/terraform.tfstate becomes github-fargate-%s/terraform.tfstate.
2. Concurrency group aws-tfstate-* becomes aws-fargate-tfstate-*, in the same commit. The note left on this job by Both halves of #1801 are still live on GCP and AWS: branch-keyed concurrency plus unconditional lock deletion #1806 said the group must move when the key does, since a group has to name the object its job locks.
3. The 11-line NOTE documenting the defect as deliberate is replaced. That comment is now false, and leaving it would tell the next reader the Lambda key is intentional.

scripts/test-aws-tfstate-platform-key.sh (new) and a new aws-tfstate-platform-key job in ci.yml, added to ci-success's needs: so it actually gates.

scripts/lib/code-scan-awk.sh: the new suite added to build_swept_scripts's basename exclusion, for the same reason the other two suites are excluded (it carries the pattern it looks for as fixture data). No behaviour change; both existing suites re-run green.

Why a guard, and why it is not a step-level scan

Nothing in Terraform ties the backend key to the platform. The key is a string a step builds by hand, the platform is a -var passed several steps later, and a wrong pairing initialises, plans and applies cleanly. A green workflow run proves nothing here, so the pairing is asserted as text.

Sites are delimited by job, not by step. This is load-bearing: deploy-aws-fargate.yml writes the backend file in "Terraform Init" and passes the platform in "Terraform Plan". A step-delimited scan (the shape test-ecr-delete-selection.sh and test-rds-deletion-protection-scope.sh use) sees a key with no platform and a platform with no key, pairs neither, and reports the whole repository clean.

Three assertions, in this order:

1. Positive first. A census of every job applying a compute_platform, emitted as file|job|key-namespace|platform|group-namespace. Count asserted non-zero; all 7 real pairings named and required to appear. The count is taken by the 5-field shape, not wc -l: an earlier version counted the scanner's own "no workflow files found" error line as one recognized job, which is exactly the "no violations by looking at nothing" reading the count exists to remove. Caught by mutation case 5 below, then repaired.
2. Negative sweep over a glob of .github/workflows/*.yml, *.yaml plus every *.sh under scripts/ and scripts/lib/. No file is named. The swept script set is asserted non-empty before the sweep runs.
3. Concurrency axis. A group in the aws-tfstate-* / aws-fargate-tfstate-* families must name the same namespace as the key, so the group cannot drift back on its own. Other families are not checked.

Plus 13 fixture cases pinning the scanner in both directions, including the split-step shape, the inverse defect (a lambda apply into the fargate namespace), a comment describing the mismatch not counting as the mismatch, and Azure/GCP jobs not being misread as AWS namespaces.

An unrecognized compute_platform value is a failure, not a pass. A third platform stops the guard and forces a namespace decision rather than a silent guess.

Mutation proof: the guard bites

Run on cp -a copies of the tree; no tracked file was mutated. The full-revert case uses git show <ref>:path > file, not git checkout <ref> -- path, which would also stage the index. Each case requires the specific FAIL line, not merely a non-zero exit, since an awk or shell syntax error also exits non-zero. All 7 caught:

mutation	caught by
rollback.yml reverted wholesale to origin/main	rollback.yml: job "rollback-aws-fargate": compute_platform=fargate applies into the github-<env>/ (lambda) state namespace
the key alone reverted	same line
the concurrency group alone reverted	concurrency group aws-tfstate-* guards a job writing the github-fargate-<env>/ (fargate) state namespace
the same defect introduced in deploy-aws-fargate.yml	deploy-aws-fargate.yml: job "deploy": ...
the defect in a brand-new workflow file	rollback-fargate-v2.yml: job "rollback": ...
the fargate job silently becoming a lambda apply	expected pairing not found: rollback.yml|rollback-aws-fargate|fargate|fargate|fargate
an emptied workflow directory	the scan recognizes no state-writing job under ...

The fifth is the one that matters for the recurrence pattern: a defect in a workflow that did not exist when the guard was written is still caught, because the sweep globs rather than naming files.

Other verification

• bash 3.2 (macOS /bin/bash 3.2.57): 23/23, exit 0.
• Both awk dialects: macOS BWK awk and mawk 1.3.4, which is what CI runs. This found a real problem in reverse: BWK awk rejects an unparenthesized ternary in an argument list at parse time while mawk accepts it, so my first version failed locally and would have passed in CI. All ternaries are now parenthesized, with a comment recording why.
• shellcheck -x: clean on the new suite and the modified shared lib.
• Sibling suites re-run after the shared-lib edit: ECR 48/48, RDS 53/53, IAM parity, all exit 0.
• actionlint: 4 findings on ci.yml, all pre-existing. Verified by running it against origin/main's copy of the same file and getting the identical 4 (SC2086 x3 and SC2129 in ci-success's "Post status" step, which my insert shifts from line 892 to 927). None introduced, none fixed.
• Rebased onto 48bae39f0 and verified by git patch-id --stable, identical before and after (cfdbc0a002f1a5ccf5acbc7cd9b150b68ac2c070), so no hunk was silently dropped.
• No terraform command was run anywhere, and no workflow was dispatched.

Out of scope, filed separately

While enumerating I found that database-migration.yml runs a bare terraform init with no -backend-config in three jobs before reading terraform output. Already tracked as LeanerCloud/cloud-commitments-platform#114. The second defect in those same lines, terraform output ... 2>/dev/null || echo "" discarding the real error, is now LeanerCloud/cloud-commitments-platform#207. Neither is touched here; those jobs never run apply, so they carry no state-corruption risk on this axis.

This PR also repairs the guards #1852 landed

Review on this PR found two Major fail-open gaps, both fixed in f1a45e3. The second one is not confined to this PR, and reviewers should know that:

build_swept_scripts in scripts/lib/code-scan-awk.sh was introduced by #1852, which merged earlier today, and was not recursive. It globbed $dir/*.sh and $dir/lib/*.sh, which names two directories the same way naming files would, and is the exact defect the helper exists to prevent one level up. test-ecr-delete-selection.sh and test-rds-deletion-protection-scope.sh call that same function, so both guards on main carry the identical blind spot right now: a scripts/aws/force-delete.sh running aws ecr delete-repository by prefix, or a scripts/aws/unprotect.sh running aws rds modify-db-instance unguarded, is opened by no suite at all today.

Fixed in the shared helper rather than locally in the new suite, so one change closes it in all three. Verified by mutation against all three, with a nested scripts/aws/ holding one offender per guard on a cp -a copy: each of the three fails naming its own file, and removing the directory returns all three to green. The counter-check takes scripts/lib/code-scan-awk.sh from git show origin/main: and runs the same fixture against it; both the ECR and RDS suites pass with the offender present, so the gap on main is demonstrated rather than asserted.

Honest qualification: scripts/ has no nested *.sh today, so recursive and non-recursive discovery return a byte-identical 26 files. This closes a latent gap, not an active miss, and nothing is currently escaping either merged guard. That is also why the new recursion assertion runs against a fixture tree rather than the real scripts/: asserting recursion where no nested file exists would pass for a directory that could not have failed it.

The first finding was local to this PR: the concurrency check only compared a group against the key namespace when a group was present, so a job with the right key and the right platform but no group passed and could apply shared state with nothing serializing it. Absence was being read as permission. A missing group is now a violation, mutation-verified by deleting the concurrency: block from rollback.yml outright.

No separate issue filed for the merged-code half, since it is repaired here in the same change.

Summary by CodeRabbit

• Bug Fixes

  • Corrected AWS Fargate rollback configuration to use Fargate-specific Terraform state namespaces and concurrency settings.

• Tests

  • Added automated checks for consistent AWS compute-platform state namespaces and concurrency groups.
  • Integrated these checks into CI success requirements.
  • Expanded configuration scanning across workflows and nested scripts.

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📝 Walkthrough

Walkthrough

The PR changes the Fargate rollback Terraform state namespace and concurrency group. It adds a scanner for AWS platform state consistency, expands recursive script scanning, and makes the scanner a required CI check.

Changes

AWS Terraform state namespace consistency

Layer / File(s)	Summary
Align Fargate rollback state and concurrency namespaces .github/workflows/rollback.yml	The Fargate rollback job now uses the Fargate-specific Terraform state key and concurrency group.
Implement namespace scanner and fixtures scripts/test-aws-tfstate-platform-key.sh, scripts/lib/code-scan-awk.sh	The scanner checks AWS platform, state-key, and concurrency-group pairings. Tests cover mismatches, missing values, comments, multi-file inputs, nested scripts, and non-AWS formats.
Enforce validation in CI .github/workflows/ci.yml	CI runs the namespace self-test with read-only repository permissions and requires it for ci-success.

Estimated code review effort: 4 (Complex) | ~45 minutes

Merge Risk: 🟡 Moderate · up to f1a45

The PR corrects the Fargate rollback state namespace and adds a validation guard, but the current guard still allows state-writing jobs without the required concurrency group and does not cover nested scripts. Those gaps could let a future state mismatch or unsynchronized state writer merge undetected, so they require explicit owner follow-up before merge.

Sequence Diagram(s)

sequenceDiagram
  participant GitHubActions
  participant test_aws_tfstate_platform_key
  participant WorkflowAndScriptFiles
  GitHubActions->>test_aws_tfstate_platform_key: run self-tests
  test_aws_tfstate_platform_key->>WorkflowAndScriptFiles: scan AWS state keys and concurrency groups
  WorkflowAndScriptFiles-->>test_aws_tfstate_platform_key: return diagnostics
  test_aws_tfstate_platform_key-->>GitHubActions: return pass/fail status

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Possibly related PRs

• LeanerCloud/CUDly#1812: Both changes update AWS Fargate Terraform state namespaces and concurrency groups.
• LeanerCloud/CUDly#1803: Both changes align rollback concurrency groups with platform-specific Terraform state namespaces.
• LeanerCloud/CUDly#1852: Both changes extend the CI guard-suite infrastructure and shared shell-script scanning.

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Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the primary change: updating the Fargate rollback Terraform state key.
Linked Issues check	✅ Passed	The PR updates the Fargate backend key and concurrency group as required by issue #1811; manual state verification is excluded.
Out of Scope Changes check	✅ Passed	The CI guard, recursive script discovery, and rollback changes directly support the stated state-namespace objectives.
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[cristim]

@coderabbitai full review

The push at 04:05Z hit the review limit, so this head has no review. The stated countdown has since elapsed. Requesting explicitly because the auto-review on push was consumed by the throttle rather than deferred.

[coderabbitai]

@cristim I used the repository review-quota guidance. I requested a full review so it includes the commits missed during throttling.

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Learning: For the LeanerCloud/CUDly repository, pace CodeRabbit review requests at one request per hour across the repository. The review quota is adaptive and shared per developer and organization; burst requests can exhaust the quota and tighten the limit. When a PR head was pushed while quota was exhausted, request a full review because an incremental review skips the unreviewed commits.

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Learning: For pull request `#1716`, when review quota exhaustion prevents automatic review of pushed commits, request a full review instead of an incremental review. An incremental review can omit those unreviewed commits.

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Actionable comments posted: 2

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Inline comments:
In `@scripts/test-aws-tfstate-platform-key.sh`:
- Around line 151-152: Update the concurrency-group validation condition in the
platform-applying job scan to report a violation when grp is empty, while
preserving the existing platform, namespace, MIXED, and mismatch checks; also
add a fixture covering a job with an AWS state key and no concurrency group.
- Around line 296-307: Update build_swept_scripts to discover all *.sh files
recursively beneath scripts/, including nested directories such as scripts/aws,
while preserving the existing sweep inputs and empty-set guard. Add a
nested-script fixture containing an invalid compute_platform/state-namespace
pairing so the assertion verifies recursive coverage.

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[cristim]

State note: this PR currently reads cleaner than it is. Do not merge at this head.

Both review threads now show as resolved. I did not resolve them; they were auto-resolved in response to my replies describing the fixes. But those fixes are committed locally only, so:

pushed head	94d2acca77670773dd3b89185e7937b049fefbf0
contains the two Major fixes?	no
unresolved threads shown	0
fix commit	f1a45e35e73e964a25f4ddcbd02b52a272e1af21, local, not pushed

So a gate check reads green while the head still has both defects: the concurrency check that reads an absent group as permission, and the non-recursive build_swept_scripts. Anyone checking the thread count rather than the tree would be misled, which is the same failure-indistinguishable-from-success shape this PR exists to guard against.

The push is deliberately held: CodeRabbit's verdict on this head landed at 04:48:11Z and its allowance is one per hour, so pushing now would draw a throttle notice rather than a review of the fixed code.

I will push once released, and will confirm afterwards, reading back from GitHub rather than from a local worktree, that the recursive find discovery and the grp == "" check are both present at the new head SHA. Until that confirmation is posted here, treat this PR as having two open Major findings regardless of what the thread count says.

My replies on the two threads should have said "committed, not yet pushed" rather than "fixed in f1a45e3". That wording is what let the threads close over an unfixed head.

[cristim]

Confirmation for the state note above: the fixes are now at the head.

pushed head	f1a45e35e73e964a25f4ddcbd02b52a272e1af21
contains the two Major fixes?	yes, verified
previous head	94d2acca77670773dd3b89185e7937b049fefbf0 (did not)

Verified by reading both files back from GitHub at that SHA via repos/.../contents/<path>?ref=<sha>, not from a local worktree, after confirming the SHA matches both the PR head and the branch ref. Verifying the right content at the wrong commit is the same class of mistake as verifying nothing.

--- finding 2: recursive discovery in the shared helper ---
PRESENT: recursive find -print0 discovery
    102:  done < <(find "$dir" -type f -name '*.sh' -print0 2>/dev/null | sort -z)
PRESENT: null-delimited read (bash 3.2 safe)
    96:  while IFS= read -r -d '' candidate; do
GONE:    the old non-recursive two-directory glob

--- finding 1: empty concurrency group is a violation ---
PRESENT: grp == "" reported as a violation
    167:        if (grp == "" && platform != "")
PRESENT: the missing-group finding text
    168:          printf "... no AWS concurrency group serializes a job applying compute_platform=%s ..."
GONE:    the old fail-open condition gated on grp != ""

Four assertions that the new code is present and two that the superseded code is gone rather than merely joined by it.

The checker was proven in both directions before I relied on it. Run against the previous head 94d2acca7 it exits 1 and names the exact stale lines (code-scan-awk.sh:83, test-aws-tfstate-platform-key.sh:151), and the same six patterns were run against the fixed tree to confirm they match there. Without that second step an unmatchable pattern would report ABSENT on every commit forever and would look identical to a working checker right up to the moment it certified nothing.

The two threads were already showing resolved before this push, so their state did not change and should not be read as a signal either way. What changed is the head.