devops

Git Basics for DevOps

Essential Git commands, branching strategies, and workflows used in DevOps

Why Git in DevOps?

Every DevOps pipeline starts with source code. Git is the version control system that tracks every change, enables collaboration, and is the trigger for CI/CD automation.

Essential Git Commands

Setup

git config --global user.name "Your Name"
git config --global user.email "you@example.com"

Starting a Repo

git init                  # new local repo
git clone <url>           # copy a remote repo

Daily Workflow

git status                # see what's changed
git add .                 # stage all changes
git add <file>            # stage a specific file
git commit -m "message"   # save snapshot
git push origin main      # push to remote
git pull                  # fetch + merge from remote

Branching

git branch feature/login  # create branch
git checkout feature/login # switch to branch
git checkout -b feature/login  # create + switch (shortcut)
git merge feature/login   # merge into current branch
git branch -d feature/login   # delete branch

Undoing Things

git restore <file>        # discard unstaged changes
git reset HEAD <file>     # unstage a file
git revert <commit-hash>  # undo a commit (safe, creates new commit)
git reset --hard <hash>   # dangerous: rewrite history

Viewing History

git log --oneline         # compact history
git log --graph --all     # visual branch graph
git diff                  # see unstaged changes
git diff --staged         # see staged changes

Branching Strategies

Git Flow

Classic strategy for teams with scheduled releases:

main ──────────────────────────────────────────► (production)
       ↑                                  ↑
develop ──────────────────────────────────► (integration)
          ↑ feature/A  ↑ feature/B

main — always production-ready
develop — integration branch
feature/* — one branch per feature
release/* — stabilization before merging to main
hotfix/* — emergency patches off main

GitHub Flow (simpler, recommended)

main ────────────────────────────────────────►
        feature/X ──► PR ──► merge to main ──► deploy

Branch off main
Make changes
Open a Pull Request
Review + CI passes
Merge → auto-deploy

Trunk-Based Development (DevOps favorite)

Everyone commits directly to main (or very short-lived branches < 1 day). Requires strong CI and feature flags. Used by Google, Facebook, Netflix.

Git in CI/CD

A typical CI trigger in GitHub Actions:

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

Every push runs tests automatically. This is the foundation of Continuous Integration.

Useful Git Aliases

git config --global alias.st status
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.lg "log --oneline --graph --all"

.gitignore

Always exclude secrets, build artifacts, and editor files:

# dependencies
node_modules/

# build output
dist/
build/
*.class

# secrets
.env
*.pem
credentials.json

# editor
.vscode/
.idea/

Quick Reference Card

Task	Command
See status	`git status`
Stage all	`git add .`
Commit	`git commit -m "msg"`
Push	`git push origin <branch>`
Pull	`git pull`
New branch	`git checkout -b <name>`
Merge	`git merge <branch>`
History	`git log --oneline`
Undo file	`git restore <file>`