CI/CD Overview

CI/CD Overview

Continuous Integration (CI) and Continuous Delivery/Deployment (CD) are the backbone of modern DevOps pipelines. They automate the process of building, testing, and releasing software.

CI vs CD

  Continuous Integration (CI):
  ┌──────┐    ┌───────┐    ┌───────┐    ┌────────┐
  │ Dev  │───▶│  Git  │───▶│ Build │───▶│  Test  │
  │ Push │    │  Push │    │       │    │        │
  └──────┘    └───────┘    └───────┘    └────────┘
                                           │
                                    Pass/Fail Report

  Continuous Delivery (CD):
  ┌────────┐    ┌────────┐    ┌────────┐
  │  Test  │───▶│ Staging│───▶│ Manual │───▶ Production
  │  Pass  │    │ Deploy │    │ Approval│
  └────────┘    └────────┘    └────────┘

  Continuous Deployment (CD):
  ┌────────┐    ┌────────┐    ┌────────────┐
  │  Test  │───▶│ Staging│───▶│ Production │
  │  Pass  │    │ Deploy │    │   Deploy   │
  └────────┘    └────────┘    └────────────┘
              No human intervention

Benefits of CI/CD

• Faster releases — Deploy multiple times per day instead of weekly
• Higher quality — Automated tests catch bugs early
• Reduced risk — Small changes are easier to debug and rollback
• Consistency — Same process every time, no manual steps
• Developer productivity — Less time on manual tasks, more on coding

Common CI/CD Tools

  ┌─────────────────────────────────────────────┐
  │           CI/CD Tools Landscape            │
  ├─────────────────┬───────────────────────────┤
  │ Self-hosted     │ Cloud-hosted             │
  ├─────────────────┼───────────────────────────┤
  │ Jenkins         │ GitHub Actions           │
  │ GitLab CI       │ CircleCI                 │
  │ TeamCity        │ Travis CI                │
  │ Bamboo          │ AWS CodePipeline         │
  │ GoCD            │ Azure DevOps Pipelines   │
  └─────────────────┴───────────────────────────┘

A Typical CI/CD Pipeline

  Code Push
     │
     ▼
  ┌──────────┐  ┌──────────┐  ┌──────────┐  ┌──────────┐  ┌──────────┐
  │  Lint &  │─▶│  Build   │─▶│  Unit    │─▶│  Deploy  │─▶│ Deploy   │
  │  Format  │  │          │  │  Tests   │  │  to      │  │ to       │
  │          │  │          │  │          │  │  Staging │  │ Prod     │
  └──────────┘  └──────────┘  └──────────┘  └──────────┘  └──────────┘
       │              │              │              │              │
     Fail=         Fail=          Fail=          Fail=         Fail=
     Stop         Stop           Stop           Stop          Rollback