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Knowledge-Base/20 - Knowledge/devops/ci-cd-basics.md

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---
title: CI/CD Basics
description: Introduction to continuous integration and continuous delivery pipelines for application and infrastructure repositories
tags:
- ci
- cd
- devops
category: devops
created: 2026-03-14
updated: 2026-03-14
---
# CI/CD Basics
## Introduction
Continuous integration and continuous delivery reduce manual deployment risk by automating validation, packaging, and release steps. Even small self-hosted projects benefit from predictable pipelines that lint, test, and package changes before they reach live systems.
## Purpose
CI/CD pipelines help with:
- Fast feedback on changes
- Repeatable build and test execution
- Safer promotion of artifacts between environments
- Reduced manual drift in deployment procedures
## Architecture Overview
A basic pipeline usually includes:
- Trigger: push, pull request, tag, or schedule
- Jobs: isolated units such as lint, test, build, or deploy
- Artifacts: build outputs or packages passed to later stages
- Environments: dev, staging, production, or similar release targets
Typical flow:
```text
Commit -> CI checks -> Build artifact -> Approval or policy gate -> Deploy
```
## Core Concepts
### Continuous integration
Every meaningful change should run automated checks quickly and consistently.
### Continuous delivery
Artifacts are always kept in a releasable state, even if production deployment requires a manual approval.
### Continuous deployment
Every validated change is deployed automatically. This is powerful but requires strong tests, rollback paths, and change confidence.
## Configuration Example
GitHub Actions workflow example:
```yaml
name: ci
on:
pull_request:
push:
branches: [main]
jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: actions/setup-node@v4
with:
node-version: 22
- run: npm ci
- run: npm test
```
## Troubleshooting Tips
### Pipeline is slow and developers stop trusting it
- Run fast checks early
- Cache dependencies carefully
- Separate heavyweight integration tests from every small change if needed
### Deployments succeed but services still break
- Add health checks and post-deploy validation
- Make environment-specific configuration explicit
- Track which artifact version reached which environment
### CI and local results disagree
- Match tool versions between local and CI environments
- Keep pipeline setup code in version control
- Avoid hidden mutable runners when reproducibility matters
## Best Practices
- Keep CI feedback fast enough to be used during active development
- Require checks before merging to shared branches
- Build once and promote the same artifact when possible
- Separate validation, packaging, and deployment concerns
- Treat pipeline configuration as production code
## References
- [GitHub Docs: Understanding GitHub Actions](https://docs.github.com/actions/about-github-actions/understanding-github-actions)
- [GitHub Docs: Workflow syntax for GitHub Actions](https://docs.github.com/actions/reference/workflows-and-actions/workflow-syntax)