#atom

Practice of automating software release preparation for reliable deployments

Core Idea: Continuous Delivery (CD) is a software development approach where code changes are automatically built, tested, and prepared for release to production, ensuring that software can be reliably deployed at any time with minimal manual intervention.

Key Elements

• Core Principles:

  • Build only once and promote the same artifacts
  • Deploy the same way to every environment
  • Smoke test every deployment
  • Make deployments routine and predictable
  • If anything fails, stop the pipeline

• Deployment Pipeline Stages:

  • Build: Compile code and create deployable artifacts
  • Unit Testing: Test individual components
  • Integration Testing: Test component interactions
  • System Testing: Test the entire application
  • Performance Testing: Verify system performance
  • User Acceptance Testing: Validate business requirements
  • Release Preparation: Final staging before production

• Implementation Components:

  • CI/CD Server: Pipeline orchestration (Jenkins, GitHub Actions)
  • Artifact Repository: Centralized storage for builds (Artifactory, Nexus)
  • Environment Management: Consistent environments (Docker, Kubernetes)
  • Configuration Management: Environment-specific settings
  • Release Automation: Scripted deployment processes
  • Deployment Strategies: Blue/green, canary, rolling deployments

• CD Pipeline Configuration Example:

  # GitHub Actions CD workflow example
  name: Continuous Delivery
  
  on:
    push:
      branches: [ main ]
  
  jobs:
    build:
      runs-on: ubuntu-latest
      steps:
        - uses: actions/checkout@v3
        - name: Build and test
          run: |
            npm ci
            npm run lint
            npm test
            npm run build
        
        - name: Create artifact
          uses: actions/upload-artifact@v3
          with:
            name: app-build
            path: build/
    
    deploy-staging:
      needs: build
      runs-on: ubuntu-latest
      steps:
        - uses: actions/download-artifact@v3
          with:
            name: app-build
            
        - name: Deploy to staging
          run: ./deploy.sh staging
          
        - name: Run smoke tests
          run: ./smoke-test.sh staging
  
    deploy-production:
      needs: deploy-staging
      runs-on: ubuntu-latest
      # Manual approval step could be here
      steps:
        - uses: actions/download-artifact@v3
          with:
            name: app-build
            
        - name: Deploy to production
          run: ./deploy.sh production
          
        - name: Verify deployment
          run: ./smoke-test.sh production
  

- **Deployment Strategies**:
    
    - **Blue/Green Deployment**: Maintain two identical environments
    - **Canary Release**: Gradual rollout to a subset of users
    - **Rolling Deployment**: Incrementally update instances
    - **Feature Toggles**: Enable/disable features without deployment
- **Benefits**:
    
    - Lower deployment risk
    - Reliable and predictable releases
    - Faster time to market
    - Reduced manual work and human error
    - Better visibility and feedback
    - Separation of deployment from release timing

## Connections

- **Related Concepts**: Continuous Integration (prerequisite for CD), Continuous Deployment (next step after CD)
- **Broader Context**: DevOps Practices (methodology encompassing CD)
- **Applications**: Release Management (process enhanced by CD)
- **Components**: Infrastructure as Code (enables consistent environments), Automated Testing (ensures release quality)

## References

1. "Continuous Delivery: Reliable Software Releases through Build, Test, and Deployment Automation" by Jez Humble and David Farley
2. "The DevOps Handbook" by Gene Kim, Jez Humble, Patrick Debois, and John Willis
3. "Accelerate: The Science of Lean Software and DevOps" by Nicole Forsgren, Jez Humble, and Gene Kim

#continuous-delivery #devops #automation #deployment #release-management

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**Connections:**
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**Sources:**
- From: Syntax - Lint como un desarrollador senior con eslint + husky + lint staged + acciones de github