Version Control 101: How Git and GitHub Power Your Development Workflow

What is Git?

• Git is an open-source, distributed version control system.

• It’s lightweight and works on almost all operating systems.

• Tracks and manages changes in code across collaborative projects.

History of Git

• BitKeeper was a commercial distributed version control system (DVCS) developed in the late 1990s by Larry McVoy. It allowed Linux kernel developers to use it for free.

• Due to a conflict over reverse-engineering, Linus Torvalds (creator of Linux) developed Git in 2005 as a free, open-source alternative to BitKeeper.

Git vs GitHub

• Git: A version control system to track changes in code. It’s software used locally for managing repositories.

• GitHub: A platform that hosts Git repositories online, offering collaboration tools like pull requests, issue tracking, and more.

• GitLab: Similar to GitHub but includes built-in CI/CD tools for automation.

• Bitbucket: A Git repository hosting platform, often integrated with Atlassian tools like Jira.

Why Git in DevOps?

• CI/CD Pipelines: Git is crucial for creating pipelines, tagging releases, and version control in DevOps.

• Infrastructure as Code (IaC): Tools like Terraform use Git to manage infrastructure configurations.

• GitOps: Git serves as the source of truth for infrastructure, automating deployments based on repository changes.

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Git Basics

Starting a Git Project

1. Initialize Git in a project:

   
    git init
   

   • This command sets up a new Git repository in your project.

2. Add files to staging area:

   
    git add <file-path>
   

   • Adds files to the staging area, preparing them for a commit.

3. Commit changes:

   
    git commit -m "Commit message"
   

   • Saves changes from the staging area into the repository with a description.

4. View commit history:

   
    git log
    git log --oneline
   

5. Check file differences:

   
    git diff
   

6. Track file history by line:

   
    git blame <file-path>
   

7. Check the repository status:

   
    git status
   

   • Shows the status of files in your working directory and staging area.

Staging Area and Commits

• Files go through these stages:Local Workspace → Staging Area → Committed to Repository

• Only staged files are committed.

• Proper commit history helps in reverting to any commit point.

Reverting to Previous Commits

1. Reset to a commit:

   
    git reset --hard <commit_id>
   

   • Moves the head to a specific commit, removing later changes.

2. Revert a commit (safer):

   
    git revert <commit_id>
   

   • Creates a new commit that reverses changes from a previous commit without deleting history.

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Collaboration in Git

Remote Repositories

• GitHub, GitLab, Bitbucket are popular hosting services for Git repositories.

• To connect your local repository to a remote server:

  
    git remote add origin <remote-url>
  

  • Origin is the name of the remote server (commonly used name).

Syncing Changes

• Push local commits to a remote repository:

  
    git push
  

Authentication Methods: HTTPS vs SSH

1. HTTPS:

   • Uses Personal Access Tokens (PAT) for authentication.

   • Simple setup but requires entering credentials unless cached.

2. SSH:

   • More secure, using public and private keys.

   • Once set up, it doesn’t require credentials for every operation.

Check remote URL type:

    git remote -v

• HTTPS looks like https://github.com/user/repo.git

• SSH looks like git@github.com:user/repo.git

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Branching in Git

Why Branching?

• Branches allow multiple developers to work in parallel without affecting the main codebase.

• Each branch represents an independent line of development.

Common Branching Commands

1. Create a new branch:

   
    git branch <branch-name>
   

2. Switch to a branch:

   
    git checkout <branch-name>
   

3. Push a branch to the remote repository:

   
    git push --set-upstream origin <branch-name>
   

Merging Branches

1. Merge a remote branch:

   
    git merge origin/<branch-name>
   

   • Merges changes from the remote branch into your current branch.

2. Merge locally and push:

   
    git checkout master
    git merge <branch-name>
    git push origin master
   

Remote Merge and Pull Workflow

1. Merge remotely using a Pull Request:

   • Merge the branch on the remote platform (e.g., GitHub) using a Pull Request.

2. Pull changes locally:

   
    git pull origin master
   

   • Updates your local master with the latest changes from the remote repository.

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Best Practices in Git

• Make frequent, meaningful commits: A separate commit for each functionality keeps the history clean.

• Use branches for features: Develop each feature on a separate branch to keep the main branch stable.

• Write descriptive commit messages: This makes the history easy to follow.

• Avoid large commits: Commit smaller, focused changes for better tracking and rollback options.