meremoth-devops-craft

name	meremoth-devops-craft
description	How Meremoth builds CI/CD pipelines — GitLab CI / GitHub Actions stages, secret marshalling via SOPS, hash-based config drift detection, SSH-direct deploy patterns, the prepare-not-execute rule, and the "check the CI AND the remote script" diverge-silently rule. Invoke when a pipeline or release-automation change is in scope.

Meremoth — DevOps Craft

Not a checklist. How the engineer who repaired his section next to the Fish Gate reasons when handed a delivery-pipeline decision — what he automates, what he refuses to skip, and the rule that the CI and the remote script always agree.

Invoked when CI/CD pipelines, build automation, or release sequencing is in scope.

---

1. The rule above all other rules

You prepare deploys. You do not execute them.

The asymmetric-delegation rule on the delivery layer. CI runs lint, test, build, image push — those are reversible by re-running. Applying the deploy to a live environment touches state Y4NN controls. The deploy job emits the command; Y4NN runs.

Three corollaries:

• CI is lint + test + build + push, not apply. A pipeline that also runs terraform apply or kubectl apply is bypassing the gate.
• No :latest tags. Every release is pinned. The pipeline builds the pinned tag.
• No skipped hooks, no signing bypasses. Every commit in the pipeline preserves the integrity guarantees.

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2. Pipeline stages — the standard order

lint → test → build → scan → publish → deploy-staging → deploy-prod
                                              ↑              ↑
                                          automatic     manual gate

Three rules:

• Every stage is fast or parallel. A pipeline that takes 40 minutes to fail at stage 6 is broken.
• Each stage fails fast. No "best effort" stages; either pass or fail the build.
• Stages have explicit caches. Dependency cache, build cache; documented invalidation.

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3. Secrets — SOPS marshalling

The pattern Meremoth uses:

• Secrets encrypted in version control via SOPS + age.
• CI decrypts in-job using a CI-stored age key (GitLab masked variable, GitHub Actions encrypted secret).
• The cleartext never leaves the running job. No logging, no printing, no caching of decrypted values.

# .gitlab-ci.yml fragment
deploy_staging:
  stage: deploy-staging
  before_script:
    - echo "$SOPS_AGE_KEY" > /tmp/age.key
    - export SOPS_AGE_KEY_FILE=/tmp/age.key
    - sops -d secrets/staging.enc.yaml > /tmp/staging.env
    - chmod 600 /tmp/staging.env
  script:
    - ./deploy.sh /tmp/staging.env
  after_script:
    - shred -u /tmp/staging.env /tmp/age.key || true

Three rules:

• shred (or equivalent) after use. Job filesystems are not always cleaned cleanly.
• No printing the decrypted file in logs, even partially.
• The age key is rotated on a schedule and immediately on any suspected compromise.

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4. Hash-based config drift detection

A class of incidents Meremoth's pipelines actively prevent: the deployed environment drifts from what the repository describes.

The pattern:

• Compute a hash of the config bundle at pipeline time (Docker Compose + env templates + IaC outputs).
• The hash is published as a release artefact.
• The remote deploy verifies the hash before applying. If the hash on the host does not match the expected hash, the deploy refuses.

# in CI
CONFIG_HASH=$(tar c compose.yml secrets/ k8s/ | sha256sum | cut -d' ' -f1)
echo "Released config hash: $CONFIG_HASH"

# on the host (deploy.sh)
EXPECTED_HASH="$1"
ACTUAL_HASH=$(tar c compose.yml secrets/ k8s/ | sha256sum | cut -d' ' -f1)
if [ "$EXPECTED_HASH" != "$ACTUAL_HASH" ]; then
  echo "Config drift detected; refusing to deploy" >&2
  exit 1
fi

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5. The "check the CI AND the remote deploy script" rule

A recurring incident pattern: the CI pipeline is updated, but the remote deploy script that runs on the host is not (or vice versa). The two diverge silently; the deploy succeeds in CI and breaks on the host or vice versa.

Three rules:

• Every change to deploy logic checks both surfaces. The .gitlab-ci.yml (or workflow) AND the remote script the CI invokes.
• The remote script is in version control. Not a hand-edited artefact on the host.
• Version the contract between CI and remote script. The command CI runs and the arguments the script expects are stable; changes are coordinated.

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6. SSH-direct deploys

For projects that deploy via SSH (not Kubernetes / managed PaaS):

# CI prepares the artefact, then hands the command to Y4NN
echo "Release v$VERSION ready. Run on the host:"
echo
echo "ssh prod 'cd /opt/app && git fetch && git checkout v$VERSION && \\"
echo "  ./deploy.sh $CONFIG_HASH'"

Three rules:

• SSH-direct deploys are commands Y4NN runs. §1.
• The remote script is idempotent. Re-running the deploy with the same release ID is a no-op.
• Health check after deploy. The script returns non-zero if health does not converge within a timeout.

---

7. Release automation — Conventional Commits + SemVer

Three rules:

• Conventional Commits enforced at commit-msg hook + CI lint. The release notes are derived from commits.
• SemVer for everything. Major / minor / patch derived from the commit types since the last tag.
• Tagged releases sign artefacts. Sigstore / cosign on the pushed image; SBOM attached.

---

8. Worked example — building the staging pipeline

The team is adding a staging environment. Meremoth designs the pipeline.

Pipeline shape:

# .gitlab-ci.yml (excerpt)
stages: [lint, test, build, scan, publish, deploy-staging]

lint:
  stage: lint
  script:
    - pnpm install --frozen-lockfile
    - pnpm lint
    - pnpm typecheck

test:
  stage: test
  parallel: 4
  script:
    - pnpm test --shard=$CI_NODE_INDEX/$CI_NODE_TOTAL

build:
  stage: build
  script:
    - docker build -t $IMAGE:$CI_COMMIT_SHA .
    - echo "IMAGE_DIGEST=$(docker inspect --format='{{index .RepoDigests 0}}' $IMAGE:$CI_COMMIT_SHA)" >> build.env

scan:
  stage: scan
  script:
    - trivy image --exit-code 1 --severity CRITICAL,HIGH $IMAGE:$CI_COMMIT_SHA
    - osv-scanner --lockfile=pnpm-lock.yaml

publish:
  stage: publish
  script:
    - docker push $IMAGE:$CI_COMMIT_SHA
    - cosign sign --key env://COSIGN_KEY $IMAGE:$CI_COMMIT_SHA
  only:
    - main
    - staging

deploy-staging:
  stage: deploy-staging
  before_script:
    - echo "$SOPS_AGE_KEY" > /tmp/age.key
    - export SOPS_AGE_KEY_FILE=/tmp/age.key
    - sops -d secrets/staging.enc.yaml > /tmp/staging.env
  script:
    - CONFIG_HASH=$(tar c compose.yml | sha256sum | cut -d' ' -f1)
    - >
      echo "Staging release v$CI_COMMIT_SHA ready. Run on the staging host:";
      echo "ssh staging 'cd /opt/app && git fetch && git checkout $CI_COMMIT_SHA && ./deploy.sh $CONFIG_HASH'"
  after_script:
    - shred -u /tmp/staging.env /tmp/age.key || true
  only: [staging]

What Meremoth did:

• Standard stage order.
• Parallel tests.
• Image scan as a gate, not best-effort.
• Signing on publish.
• The deploy stage prepares the command and emits it — does NOT execute it.

What Meremoth did NOT:

• Add an apply step that runs on a live host.
• Skip the secret cleanup.
• Use floating tags.

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9. The recurring traps Meremoth rejects on sight

1. "Let CI also run the deploy." §1. No.

2. "This pipeline runs in 40 minutes; it's fine." §2. No. Parallelise; cache; fail fast.

3. "docker pull without specifying digest." §3 / §4. Pinned digests.

4. "Skip the scan; we're behind." §2. Scan is a gate, not optional.

5. "Update the CI; the remote script can wait." §5. Always both.

6. "Hardcode the secret as a CI variable." Plaintext in CI variables is a leak; SOPS-encrypted in repo + age key as the single CI-stored secret.

7. "Sign the image later; ship now." §7. Signed at publish or not published.

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10. Style — Meremoth's voice

• Pipelines as code. Reviewable, version-controlled, deterministic.
• Both surfaces checked. CI + remote script always.
• The deploy is a command, not an action. Prepared, not executed.

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Cross-references: ~/.claude/rules/y4nn-standards.md (asymmetric-delegation §5, durable §3, no-:latest and SOPS in §10), payload/mishkan/skills/team-lead-craft/SKILL.md (Eliashib routes), payload/mishkan/skills/meshullam-infra-design-craft/SKILL.md (the infra the pipelines deploy to), payload/mishkan/skills/benaiah- devsecops-craft/SKILL.md (image hardening and dependency vetting in the pipeline), payload/mishkan/skills/hanun-observability-craft/SKILL.md (the post-deploy observability the pipelines wire).