finops-waste

What this skill does

# /finops:waste

Identify GitHub Actions waste patterns and provide actionable fix suggestions. Analyzes skipped runs, bot triggers, missing concurrency groups, and missing path filters.

## When to Use This Skill

| Use this skill when... | Use a sibling instead when... |
|---|---|
| You want actionable fixes for CI cost waste — concurrency, path filters, bot guards | You need a high-level billing and health snapshot — use `/finops:overview` |
| You need to add `cancel-in-progress` to PR workflows | You need workflow run frequency and duration stats — use `/finops:workflows` |
| You are auditing skipped runs and bot-triggered noise | You are auditing cache bloat or stale caches — use `/finops:caches` |
| You want to fix one repo's workflow config | You want to rank waste across many repos — use `/finops:compare` |

## Context

- Current repo URL: !`git remote get-url origin`
- Workflow files: !`find .github/workflows -maxdepth 1 \( -name '*.yml' -o -name '*.yaml' \)`

## Parameters

| Parameter | Description | Default |
|-----------|-------------|---------|
| `repo` | Repository in owner/name format | Current repository |

## Execution

**1. Run API-based waste analysis:**

```bash
bash "${SKILL_DIR}/scripts/waste-analysis.sh" "$REPO"
```

**2. Workflow file analysis (requires local filesystem):**

```bash
echo ""
echo "=== Workflow File Analysis ==="

for f in .github/workflows/*.yml .github/workflows/*.yaml 2>/dev/null; do
  [ -f "$f" ] || continue
  name=$(basename "$f")
  issues=""

  # Check for concurrency
  if ! grep -q "concurrency:" "$f"; then
    issues="${issues}missing-concurrency "
  fi

  # Check for path filters (on push/pull_request without paths)
  if grep -qE "^\s*(push|pull_request):" "$f" && ! grep -q "paths:" "$f"; then
    issues="${issues}no-path-filter "
  fi

  # Check for bot filter
  if ! grep -q "github.event.sender.type" "$f" && ! grep -q "github.actor" "$f"; then
    issues="${issues}no-bot-filter "
  fi

  # Check for cancel-in-progress
  if grep -q "pull_request:" "$f" && ! grep -q "cancel-in-progress:" "$f"; then
    issues="${issues}no-cancel-in-progress "
  fi

  if [ -n "$issues" ]; then
    echo "  $name: $issues"
  else
    echo "  $name: OK"
  fi
done
```

## Fix Suggestions

After analysis, provide specific fixes based on findings:

### Fix: Missing Concurrency Group

```yaml
# Add to workflow file at top level or per-job
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true  # For PR workflows
```

### Fix: Bot Trigger Filter

```yaml
jobs:
  build:
    # Skip if triggered by a bot
    if: github.event.sender.type != 'Bot'
    runs-on: ubuntu-latest
    steps: ...
```

Or for specific bots:
```yaml
    if: github.actor != 'dependabot[bot]' && github.actor != 'renovate[bot]'
```

### Fix: Add Path Filters

```yaml
on:
  push:
    branches: [main]
    paths:
      - 'src/**'
      - 'package.json'
      - 'package-lock.json'
    paths-ignore:
      - '**.md'
      - 'docs/**'
      - '.github/**'
  pull_request:
    paths:
      - 'src/**'
      - 'package.json'
```

### Fix: Cancel Duplicate PR Runs

```yaml
concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
  cancel-in-progress: true
```

## Output Format

```
=== Waste Analysis: org/repo ===

=== Skipped Runs ===
Total runs: 100
Skipped: 15 (15%)

By workflow:
  CI: 10 skipped
  CodeQL: 5 skipped

=== Bot-Triggered Runs ===
Bot-triggered: 25/100 runs

By bot:
  dependabot[bot]: 15 runs
  renovate[bot]: 10 runs

=== Workflow File Analysis ===
  ci.yml: missing-concurrency no-path-filter
  deploy.yml: OK
  codeql.yml: no-bot-filter

=== Potential Duplicate Runs ===
  Commit abc1234: 3 runs (CI, CodeQL, Security)

=== High-Frequency Workflows ===
  CI: 67 runs in sample - review trigger conditions
```

## Agentic Optimizations

| Context | Command |
|---------|---------|
| Skipped runs count | `gh run list --limit 100 --json conclusion --jq '[.[] | select(.conclusion=="skipped")] | length'` |
| Failed runs (compact) | `gh run list --limit 50 --status failure --json name,createdAt` |
| Workflow file check | `bash "${SKILL_DIR}/scripts/waste-analysis.sh" "$REPO"` |
| Check concurrency in file | `grep -l "concurrency:" .github/workflows/*.yml` |
| Bot-triggered runs | `gh run list --limit 100 --json actor,conclusion --jq '[.[] | select(.actor.login | test("\\[bot\\]"))] | length'` |

## Post-actions

1. **Offer to apply fixes**: For each issue found, offer to edit the workflow file directly
2. **Prioritize by impact**: Focus on high-frequency workflows first
3. **Test recommendations**: Suggest testing changes on a feature branch first
4. **Create tracking issue**: Optionally create a GitHub issue to track optimization work