/configure:config-sync

Extract, compare, and propagate tooling config improvements across FVH repos.

When to Use This Skill

| Use this skill when... | Use another approach when... | |------------------------|------------------------------| | Comparing a workflow/config across all FVH repos | Configuring a single repo's workflow from scratch — use /configure:workflows | | Propagating an improvement from one repo to many | Debugging a failing CI run — use github-actions-inspection | | Identifying which repos have outdated configs | Creating a reusable workflow — use /configure:reusable-workflows | | Extracting novel patterns from a repo to share | Checking a single repo's compliance — use /configure:status |

Context

Workspace root: /Users/lgates/repos/ForumViriumHelsinki
Repos: !fd -t d -d 1 . /Users/lgates/repos/ForumViriumHelsinki --exclude .git --exclude node_modules
Current directory: !pwd

Parameters

Parse mode and options from command arguments:

Modes

extract [repo-name] — Identify improvements in a source repo
diff <file-pattern> — Compare a specific config across all repos
apply <file-pattern> [--from repo] [--to repo1,repo2,...|--all] — Propagate config to targets

Options

--from <repo> — Source repo for apply mode (default: best version detected)
--to <repo1,repo2,...> — Target repos (comma-separated)
--all — Target all repos that have the file
--dry-run — Show what would change without creating branches/PRs (default behavior)
--confirm — Actually create branches and PRs

Config Categories

Tracked files fall into five sync tiers: Wholesale (copy verbatim: claude.yml, renovate.json), Parameterized (shared core + variation points), Structural (justfile recipe names), Pattern-based (Dockerfile*, by stack), and Reference (compare and report). Full file patterns, variation points, and stack detection: references/config-tiers.md — read it when classifying a file in Extract Step 3 or Apply Step 3.

Execution

Extract Mode

Goal: Scan a repo and identify improvements that could benefit other repos.

Step 1: Identify the source repo

If repo name provided, use /Users/lgates/repos/ForumViriumHelsinki/<repo-name>. Otherwise use the current working directory (must be inside an FVH repo).

Step 2: Scan tooling files

Scan for all tracked config categories:

fd -t f -d 3 '(claude|renovate|auto-merge|release-please|container-build|Dockerfile|justfile|skaffold)' <repo-path>

Also check:

.github/workflows/*.yml
justfile
Dockerfile*
renovate.json
release-please-config.json
.release-please-manifest.json
skaffold.yaml

Step 3: Compare against workspace patterns

For each file found:

Wholesale tier: Hash the file content and compare against the most common version across all repos. Report if this repo has a newer/different version.
Parameterized tier: Extract the shared core (strip known variation points) and compare structure.
Structural tier (justfile): Check for standard recipes (default, help, dev, build, clean, lint, format, format-check, test, pre-commit, ci). Report missing standard recipes and non-standard names (e.g., check instead of lint).
Pattern-based tier: Detect tech stack, then check for best practices:
- Pinned base images (not latest)
- .dockerignore present
- Multi-stage builds
- Non-root user
- SHA-pinned GitHub Actions
- SBOM/provenance attestation
Reference tier: Note divergences from the most common configuration.

Step 4: Generate extract report

Emit the report (wholesale/parameterized/structural/pattern-based sections, then "Potential Improvements to Propagate"). Template: references/report-templates.md.

Diff Mode

Goal: Compare a specific file across all FVH repos.

Step 1: Resolve file pattern

Interpret the file pattern argument:

Full path: .github/workflows/claude.yml
Short name: claude.yml → search in .github/workflows/
Glob: *.yml → match all workflows

Step 2: Find the file across repos

fd -t f '<pattern>' /Users/lgates/repos/ForumViriumHelsinki --max-depth 4

Step 3: Group by content hash

For each found file, compute a content hash:

shasum -a 256 <file>

Group files by identical hash. Sort groups by size (largest first = most common version).

Step 4: Identify the "best" version

Heuristics for selecting the canonical version:

Most common hash (majority rules)
If tie: most recently modified
If tie: from infrastructure repo (reference repo)

Step 5: Generate diff report

Report each hash group (canonical first, with repo list and differences), repos missing the file, and a recommendation. For small files (< 100 lines), show an inline unified diff between the canonical and each outlier group. Template: references/report-templates.md.

Apply Mode

Goal: Propagate a config file from source to target repos.

Step 1: Determine source

If --from specified, use that repo's version
Otherwise, run diff mode internally to find the canonical version

Step 2: Determine targets

If --to specified, use those repos
If --all, use all repos that currently have the file (excluding source)
Otherwise, ask the user which repos to target

Step 3: Determine sync strategy by tier

Wholesale: Copy file verbatim to targets.

Parameterized: Copy file but preserve known variation points:

auto-merge-image-updater.yml: preserve BRANCH_PREFIX value
release-please.yml: preserve extra publish/deploy jobs

Structural (justfile): Do NOT overwrite. Instead:

Add missing standard recipe stubs (commented templates)
Suggest renaming non-conforming recipes
Preserve all project-specific recipes and recipe bodies

Pattern-based: Only apply general improvements matching the target's stack:

Pin unpinned base images
Add missing .dockerignore
Update SHA-pinned actions
Do NOT change build args, multi-arch config, or app-specific steps

Reference: Show diff and ask user to confirm each change.

Step 4: Preview changes (default / --dry-run)

For each target repo, show the unified diff of what would change, plus a total. Template: references/report-templates.md.

Step 5: Execute changes (--confirm or user approval)

For each target repo:

Create a branch: config-sync/<filename-slug>
Copy/update the file
Commit with conventional message: chore: sync <filename> from <source-repo>
Push and create PR via gh pr create

Full command sequence and the quoted-heredoc PR-body rule (never backslash-escape inside <<'EOF'): references/apply-execution.md. Report one line per repo with the PR link — template in references/report-templates.md.

Agentic Optimizations

| Context | Command | |---------|---------| | Quick workflow comparison | /configure:config-sync diff claude.yml | | Find improvements in a repo | /configure:config-sync extract theme-management | | Propagate renovate config | /configure:config-sync apply renovate.json --from infrastructure --all | | Preview changes only | /configure:config-sync apply claude.yml --all (dry-run is default) | | Create PRs | /configure:config-sync apply claude.yml --all --confirm |

Safety

Dry-run by default: apply only shows diffs unless --confirm is passed or user explicitly approves
Never overwrites justfile recipe bodies: Only adds stubs and suggests renames
Stack-aware Dockerfile sync: Only applies improvements matching the target's tech stack
Preserves parameterized variation points: Known customizations are not overwritten