name: deploying-app description: Prepares applications for production by generating Dockerfiles, CI/CD pipelines, and platform configurations. Supports Docker, Vercel, Netlify, and GitHub Actions.

Deployment & DevOps Engineer

When to use this skill

• When the user asks "how do I put this online?" or "deploy this to Vercel".
• When the user needs to "dockerize" the app.
• When setting up automated testing/deployment (CI/CD).

Workflow

1. Identify Target: Where is it going?
   • PaaS: Vercel (Next.js), Netlify (Static), Heroku/Railway (Node/Python).
   • Container: Docker (Universal).
   • Mobile: App Store (iOS) & Google Play (Android) via Fastlane.
2. Configuration: Generate the specific config file.
   • Vercel: vercel.json (rarely needed, usually zero-config).
   • Docker: Dockerfile + .dockerignore.
   • Mobile: fastlane/Appfile + fastlane/Fastfile.
   • GitHub: .github/workflows/deploy.yml.
3. Optimization: Ensure build scripts are efficient (multi-stage builds for Docker).

Instructions

1. Docker Strategy (The Universal Container)

Always use Multi-Stage Builds to keep images small.

• Stage 1 (Builder): Install all dependencies, build the app.
• Stage 2 (Runner): Copy ONLY the build output (e.g., .next/standlone, dist/) to a lightweight Alpine Node/Python image.

2. Docker Next Steps (After generating Dockerfile)

1. Build It: docker build -t my-app .
2. Test It: docker run -p 3000:3000 my-app
3. Ship It: Push to a registry (Docker Hub, AWS ECR) -> docker push my-repo/my-app.

3. Mobile Deployment (Fastlane)

For React Native or Flutter:

• Init: Run fastlane init inside android/ and ios/ folders.
• Match: Use fastlane match to handle painful iOS certificates automatically.
• Lanes: Create a deploy lane that increments build number -> builds app -> uploads to Store.

4. CI/CD Pipelines (GitHub Actions)

Standard "Build & Test" workflow:

• Trigger: push to main.
• Job 1: Checkout code.
• Job 2: Install dependencies (cache them!).
• Job 3: Run Tests (npm test).
• Job 4: (Optional) Deploy to staging/prod.

3. Platform Specifics

• Vercel: Ensure "Root Directory" is set correctly if using a monorepo.
• Railway/Heroku: Require a valid PORT env variable reference in code.

Self-Correction Checklist

• "Did I create a .dockerignore?" -> Critical to prevent node_modules from bloating the build context.
• "Did I expose the right port?" -> Check EXPOSE 3000 in Dockerfile.