Skill: Generate GitHub Workflow

Purpose

Produce GitHub Actions workflow files that satisfy this skill's Appendix A: Workflow output contract for a wide range of software projects. Standardized structure, triggers, and security reduce CI/CD setup cost and improve maintainability and auditability while avoiding common security and permission issues. This skill only produces workflow YAML; it does not chain to documentation or rule skills. If the user later needs README or AGENTS.md updates, invoke those skills separately.

Core Objective

Primary Goal: Generate a complete, spec-compliant, and immediately runnable GitHub Actions workflow YAML file for the user's scenario, stack, and security posture — requiring only placeholder substitution to deploy.

Success Criteria (ALL must be met):

1. ✅ Appendix A compliant: Output satisfies all mandatory structure and security requirements in Appendix A (name, on, jobs, runs-on, steps, pinned actions, no hardcoded secrets)
2. ✅ Narrow triggers: on block is scoped to specific branches/paths/tags — no bare on: push without filters
3. ✅ Minimal permissions: permissions set at workflow or job level to the minimum required for the scenario type (CI: contents: read; release: contents: write, packages: write)
4. ✅ Stack-aligned: Runner, language version, package manager, and commands match the user's specified stack
5. ✅ User confirmed before write: Required notes and placeholders are listed and user confirmation obtained before writing to .github/workflows/

Acceptance Test: After the user replaces placeholders, can the workflow run in the target repo without further modification beyond secret names and environment-specific values?

Scope Boundaries

This skill handles:

• Generating complete GitHub Actions workflow YAML for CI, PR check, release, and scheduled scenarios
• Security hardening (pinned actions, minimal permissions, no hardcoded secrets)
• Stack alignment (Node/Python/Go/Rust runners, package managers, build commands)
• Multi-workflow generation (CI + Release split into separate files)
• Conflict detection with existing workflows
• Go + Docker + GHCR + GoReleaser patterns (see Appendix B)

This skill does NOT handle:

• Chaining to documentation skills (README, AGENTS.md updates) — invoke those separately after workflow generation
• Writing to .github/workflows/ without user confirmation
• Overwriting existing workflows without warning
• Implementing build/release logic already defined in .goreleaser.yaml or Dockerfile
• Generating non-GitHub CI/CD (GitLab CI, Jenkins, etc.)

Handoff point: After generating and confirming workflow YAML, write files to .github/workflows/ with user approval. For documentation updates triggered by new workflows, use documentation skills separately.

Use Cases

• New project setup: Add CI (build, test, lint) or PR-check workflows to a new repo.
• Unified standards: Align workflow style and naming across many repos for ops and audit.
• Fill gaps: Add missing CI/release/scheduled workflows to legacy projects, with minimal permissions and pinned versions.
• Scenario-based: Generate YAML for a given scenario (e.g. "run tests only on PR", "build and publish on tag").

When to use: When the user or project needs to "create or add GitHub workflows for the current or specified project."

Scope: This skill's output follows the embedded Appendix A (narrow triggers, minimal permissions, pinned versions, auditable). Generic templates (e.g. skills.sh github-actions-templates) are more general; this skill emphasizes security and maintainability.

Behavior

Principles

• Appendix A is authoritative: Output YAML must satisfy Appendix A (structure, naming, security, maintainability).
• Narrow triggers: on must specify branches/paths/tags; avoid triggering on every push. Common pattern: push/pull_request with branches or paths. Release workflows must trigger only on version tags (e.g. push: tags: ['v*']) and live in a separate file from CI.
• Minimal permissions: When the workflow needs repo write, PR, or Secrets, set permissions at workflow or job level to the minimum required; e.g. CI contents: read, release contents: write, packages: write; avoid all.
• Pinned versions: Pin third-party actions (commit SHA or major-version tag); do not use @master or unpinned refs; prefer specific versions for security/scan actions (e.g. Trivy).

Tone and style

• Use objective, technical language; keep workflow and step name short and readable for the Actions log.
• Match the project stack: choose runner, package manager, and build commands by project type (Node/Python/Go/Rust) and existing conventions; if the project already has workflows, align naming and style.

Input-driven

• Use the user's scenario (e.g. "CI: run tests on PR", "Release: build and upload on tag") and stack (language, package manager, test/build commands) to generate the workflow; use sensible placeholders when information is missing and mark them for replacement; do not invent commands or paths.

Interaction

• Confirm before write: After generating YAML, list required notes (placeholders, branch names, Secret names the user must set), then ask for confirmation; do not write to .github/workflows/ or commit without user confirmation.
• Multiple files / release: If generating several workflows (e.g. CI + Release) or using write permissions (contents: write, packages: write), list files to be created/overwritten and permission scope, then confirm before writing.
• Conflicts: If the target path already has a workflow with the same or overlapping purpose, warn and ask whether to overwrite or save elsewhere; do not overwrite silently.

Input & Output

Input

• Scenario: Purpose (CI, PR check, release, scheduled, matrix).
• Stack: Language and version (e.g. Node 20, Python 3.11, Go 1.21), package manager (npm/pnpm/yarn, pip, cargo), test/build/release commands.
• Triggers: Branches (e.g. main, develop), path filters, optional workflow_dispatch.
• Target path: Where to write the file(s), default .github/workflows/ under project root; for multiple workflows, specify each filename (e.g. ci.yml, release.yml).

Output

• Workflow YAML: Full file content conforming to Appendix A, ready to write to .github/workflows/<name>.yml.
• Notes: List placeholders (e.g. npm run test, branch main), Secret names, and any items the user must configure.

Restrictions

Hard Boundaries

• Do not violate Appendix A: Output must have name, on, jobs, and each job must have runs-on and steps; do not use unpinned third-party actions or hardcoded secrets.
• Do not over-trigger: Do not use bare on: push with no branch/path filter unless the user explicitly requests it.
• Do not invent commands: Use placeholders for unknown test/build/release commands and mark "replace with actual command"; do not invent scripts or paths.
• Do not ignore existing workflows: If the project already has .github/workflows/, align naming and style and avoid duplication or conflict.
• Do not duplicate build logic: If the project uses GoReleaser, Dockerfile, etc. for build and image shape, the workflow only triggers, logs in, and passes args (e.g. GITHUB_TOKEN, BUILDX_BUILDER); do not reimplement that logic.

Skill Boundaries

Do NOT do these (other skills handle them):

• Do NOT chain to documentation or README skills — invoke those separately
• Do NOT write to .github/workflows/ without user confirmation
• Do NOT overwrite existing workflows silently
• Do NOT reimplement build/release logic already defined in .goreleaser.yaml or Dockerfiles
• Do NOT generate CI/CD for non-GitHub platforms (GitLab CI, Jenkins, etc.)

When to stop and hand off:

• After writing workflow files with confirmation, hand off to documentation skills if README/AGENTS.md updates are needed
• When user needs registry or secrets configuration, provide guidance but do not automate external service setup

Self-Check

Core Success Criteria

• Appendix A compliant: Output satisfies all mandatory structure and security requirements in Appendix A (name, on, jobs, runs-on, steps, pinned actions, no hardcoded secrets)
• Narrow triggers: on block is scoped to specific branches/paths/tags — no bare on: push without filters
• Minimal permissions: permissions set at workflow or job level to the minimum required for the scenario type
• Stack-aligned: Runner, language version, package manager, and commands match the user's specified stack
• User confirmed before write: Required notes and placeholders are listed and user confirmation obtained before writing to .github/workflows/

Process Quality Checks

• Appendix A: Does output satisfy mandatory structure and security in Appendix A?
• Triggers: Is on narrowed to specific branches/paths/tags?
• Permissions and security: Are minimal permissions set? Third-party actions pinned? No hardcoded secrets?
• Runnable: After the user replaces placeholders, can the workflow run in the target repo?
• Stack alignment: Runner, language version, package manager, and commands match the user's stack?
• Step order and deps: For multi-step jobs (e.g. QEMU → Buildx → login → GoReleaser), is order correct and are ids/env vars passed? See Appendix B for Go + Docker + GoReleaser.

Acceptance Test

After the user replaces placeholders, can the workflow run in the target repo without further modification beyond secret names and environment-specific values?

Examples

Example 1: Node CI (test + lint on PR)

Input: Scenario: CI. Stack: Node 20, pnpm, test pnpm test, lint pnpm lint. Trigger: pull_request to main. File: ci.yml.

Expected: Single ci.yml with name e.g. "CI"; on: pull_request: branches: [main]; job on ubuntu-latest with checkout, setup Node/pnpm, install, lint, test; use official actions/checkout and pnpm/action-setup (or equivalent) pinned; no hardcoded secrets; permissions read-only if set.

Example 2: Go PR check with path filter

Input: Scenario: PR check. Stack: Go 1.21, test go test ./.... Trigger only when go.mod or *.go change. File: pr-check.yml.

Expected: on.pull_request with paths: ['**.go', 'go.mod']; job with actions/setup-go pinned, steps checkout, setup Go, go test; permissions omitted or contents: read if no write needed.

Example 3: Go release (Docker + GHCR + GoReleaser)

Input: Scenario: CD/release. Stack: Go, Docker multi-arch (amd64/arm64), GoReleaser for image and GitHub Release. Trigger: only push tags v*. File: release.yml.

Expected: on: push: tags: ['v*']; permissions include contents: write, packages: write. Steps: Checkout (fetch-depth: 0) → Set up Go (go-version-file: go.mod, cache) → Set up QEMU (linux/amd64, linux/arm64) → Set up Docker Buildx (id: buildx, same platforms) → Login to GHCR (docker/login-action, ghcr.io) → GoReleaser (goreleaser/goreleaser-action pinned, pass GITHUB_TOKEN and BUILDX_BUILDER: ${{ steps.buildx.outputs.name }}). Do not reimplement logic defined in .goreleaser.yaml/Dockerfile. See Appendix B.

Example 4 (edge): Minimal info

Input: Project: legacy-api. No description. Language and commands unknown. User wants "at least one CI placeholder workflow".

Expected: Produce one structurally complete, Appendix A–compliant YAML; use placeholders for runner and steps (e.g. "Specify runner and install/test commands") and mark "to be replaced"; keep on narrow (e.g. pull_request: branches: [main]); do not invent test or build commands; keep name, on, jobs, runs-on, steps, and recommended fields (e.g. permissions) so the user can fill in later.

Appendix A: Workflow output contract

The following are mandatory for workflow files produced by this skill; use this appendix for self-check.

Scope: YAML workflow files produced by this skill for a project's .github/workflows/.

A.1 File and path

• Location: Must live under the target project's .github/workflows/.
• Naming: kebab-case, extension .yml or .yaml; name should reflect purpose (e.g. ci.yml, pr-check.yml, release.yml).
• One file, one workflow: One file defines one workflow; split into multiple files for complex cases; avoid many unrelated jobs in one file.

A.2 Required structure

Each workflow YAML must contain (order recommended):

Optional but recommended: permissions, concurrency, env.

A.3 Naming and readability

• Job id: kebab-case, clear meaning (e.g. build, test, lint, deploy-preview).
• Step name: Short, scannable description for the Actions log.
• Workflow name: Align with filename and other workflows in the repo.

A.4 Security and minimal permissions

• Permissions: If permissions is not set, GitHub uses default GITHUB_TOKEN permissions. For sensitive operations, set permissions at workflow or job level to the minimum needed. By type: CI (build/test/scan only) → contents: read; release (Release, GHCR push) → explicit contents: write, packages: write; avoid default or all.
• Secrets: Inject secrets via Secrets; never hardcode keys, tokens, or passwords in YAML.
• Third-party actions: Prefer official or widely used actions; pin version (commit SHA or major-version tag); do not use @master or unpinned; use specific versions for security/scan actions to reduce drift.

A.5 Maintainability

• CI vs CD (recommended): CI only builds, tests, and scans; no release. CD (image push, GitHub Release) runs only on version tags (e.g. v*). Use separate files (e.g. ci.yml, release.yml); do not mix "run on every push" and "release only on tag" in one workflow.
• Reuse: Extract common logic into Composite Actions or reusable workflows.
• Comments: Briefly comment non-obvious triggers, matrix strategy, or env usage; keep comments short.
• Project alignment: Runner, language version, package manager, and commands must match the target project; if the project has existing workflows, align style and naming.

A.6 Self-check (producer)

After producing the workflow:

• File is under .github/workflows/ with a kebab-case name.
• Contains name, on, jobs; each job has runs-on and steps.
• on is narrowed to specific branches/paths/tags.
• No hardcoded secrets; third-party actions pinned (specific version for security/scan).
• Step and job names are clear; consistent with project stack and existing workflow style.
• YAML is valid (indent, no duplicate keys); step order and dependencies are correct.

Appendix B: Go + Docker + GHCR + GoReleaser

Conventions and practices for Go + Docker + GHCR + GoReleaser workflows; follow together with the main skill and Appendix A when generating or editing such workflows.

B.1 Layout

• CI and CD separate: Two workflows.
  • CI (e.g. ci.yml): push/pull_request to main branch. Build, test, security scan only; no release.
  • CD (e.g. release.yml): Only on push of version tags (e.g. v*). Publish image and GitHub Release.
• Do not mix "run on every push" and "release only on tag" in one workflow.

B.2 Permissions

• Set permissions explicitly. CI: contents: read. Release: contents: write, packages: write. Do not use all.

B.3 Steps and order

Go

• Use actions/setup-go@v5 with go-version-file: go.mod. Enable cache: true. For release, checkout with fetch-depth: 0 (needed for GoReleaser); CI can use the same for consistency.

CI (Example Order)

1. Checkout (fetch-depth: 0)
2. Set up Go (go.mod + cache)
3. go test ./...
4. govulncheck: go install golang.org/x/vuln/cmd/govulncheck@latest then govulncheck ./...
5. Docker Buildx (setup only, single platform)
6. Build image for scanning: single arch linux/amd64, push: false, load: true, tag e.g. local/your-app:ci-${{ github.sha }}
7. Trivy on that image: severity: HIGH,CRITICAL, ignore-unfixed: true, exit-code: 1 so CI fails on findings

Multi-arch in Release only; CI scans single arch for speed.

Release (Example Order)

1. Checkout (fetch-depth: 0)
2. Set up Go (go.mod + cache)
3. Set up QEMU: docker/setup-qemu-action, platforms: linux/amd64,linux/arm64
4. Set up Docker Buildx: id: buildx, driver: docker-container, platforms: linux/amd64,linux/arm64
5. Login to GHCR: docker/login-action, registry ghcr.io, password secrets.GHCR_TOKEN || secrets.GITHUB_TOKEN, logout: true
6. GoReleaser: goreleaser/goreleaser-action@v6, args: release --clean, env GITHUB_TOKEN and BUILDX_BUILDER: ${{ steps.buildx.outputs.name }}

QEMU before Buildx; Buildx platforms must match QEMU. GoReleaser needs the Buildx builder name for multi-arch, so set id: buildx and pass BUILDX_BUILDER.

B.4 Relation to repo config

• Docker image: Shape is defined in .goreleaser.yaml and Dockerfile; workflow does not duplicate build logic.
• GHCR: Image path and tagging in GoReleaser config; workflow only logs in and passes GITHUB_TOKEN and Buildx builder.
• Makefile: Local build/test can stay; CI steps can align with Make targets but need not depend on them.

B.5 When editing

1. Full flow: Changing one job may affect the whole flow; verify checkout → Go → QEMU → Buildx → login → GoReleaser order and deps.
2. Action versions: Use current major versions (e.g. checkout@v4, setup-go@v5, setup-buildx-action@v3, goreleaser-action@v6); check changelog for breaking changes when upgrading.
3. Trivy: Pin version (e.g. @0.33.1) to avoid CI breakage from behavior changes.
4. YAML: Check indent and no duplicate keys; validate with a tool after edits.

B.6 Lessons learned

Inspect workflow history: git log --oneline -- .github/workflows/

References

• GitHub Actions docs
• Workflow syntax
• Security hardening