Installing Git and Configuring the Environment

Why Version Control Starts with a Proper Setup

Before you write a single line of production code, your environment must be configured correctly. Git is the industry-standard distributed version control system used across virtually every software development workplace. Installing it properly and configuring your identity ensures that every commit you record is traceable, recoverable, and ready for team collaboration.

Installing Git

On Linux

Most Linux distributions ship Git through their native package managers. Open a terminal with sufficient privileges and run the appropriate command for your distribution:

• Debian / Ubuntu family: `sudo apt update && sudo apt install git`
• Red Hat / Fedora / CentOS family: `sudo dnf install git`

The package manager resolves dependencies automatically and places the Git binaries in your system PATH. After the installation completes, confirm it succeeded:

```

git --version

```

The terminal should return a version string such as `git version 2.x.x`. Record this exact string in your lab log. If the command is not found, the installation did not complete successfully — re-read the output for error messages before continuing.

On Windows

Download the official installer from git-scm.com. During setup, accept the recommended defaults unless your instructor specifies otherwise. The installer adds Git Bash, a POSIX-compatible terminal, along with the core Git tools. After installation, open Git Bash or PowerShell and run `git --version` to verify.

Configuring Your Global Identity

Every commit in Git is stamped with the author's name and email address. This is not optional — without it, some Git workflows refuse to commit. Set your identity globally so it applies to every repository on your workstation:

```

git config --global user.name "Your Full Name"

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

```

Use the same email address you will register with GitHub so that commits link correctly to your profile.

Choosing a Text Editor

Git opens a text editor whenever you write a commit message or resolve a conflict interactively. Set your preferred editor now:

```

git config --global core.editor nano

```

Replace `nano` with `vim`, `code --wait` (Visual Studio Code), or another editor you are comfortable with. The `--wait` flag tells VS Code to pause Git until you close the file.

Setting the Default Branch Name

Modern Git repositories use `main` as the default branch name. Configure this before you create any repositories:

```

git config --global init.defaultBranch main

```

Verifying Your Configuration

Display all active settings with:

```

git config --list

```

You should see `user.name`, `user.email`, `core.editor`, and `init.defaultBranch` in the output. Copy this output into your lab log and have it signed off by your instructor.

Git stores global settings in a plain text file at `~/.gitconfig` on Linux/macOS and in your user profile folder on Windows. You can read this file directly to inspect or manually edit settings.

Setting Up SSH Authentication for GitHub

Passwords for remote repositories are increasingly deprecated. SSH key-pair authentication is the standard secure method for communicating with GitHub.

Generating a Key Pair

Run the following command in your terminal:

```

ssh-keygen -t ed25519 -C "you@example.com"

```

The `-t ed25519` flag selects a modern, compact elliptic-curve algorithm. When prompted for a file location, press Enter to accept the default (`~/.ssh/id_ed25519`). When prompted for a passphrase, entering one adds an extra layer of protection — this is strongly recommended on shared or lab workstations.

Two files are created: `id_ed25519` (your private key, never shared) and `id_ed25519.pub` (your public key, safe to share).

Adding the Public Key to GitHub

1. Display the public key: `cat ~/.ssh/id_ed25519.pub`

2. Copy the entire output.

3. In your GitHub account, go to Settings → SSH and GPG keys → New SSH key.

4. Paste the public key, give it a descriptive title, and save.

Testing the Connection

```

ssh -T git@github.com

```

A successful response reads: Hi username! You've successfully authenticated, but GitHub does not provide shell access. Log this message verbatim. If authentication fails, check that the correct public key was added and that your SSH agent has loaded the private key (`ssh-add ~/.ssh/id_ed25519`).

Safety and Best Practices

• Never share your private key file. If you accidentally expose it, delete the key pair, revoke the public key on GitHub, and generate a new pair immediately.
• Use a passphrase on any key stored on a shared lab machine.
• On Linux lab VMs, avoid running installation commands as the root user when `sudo` is available — using least-privilege accounts limits damage from mistakes.
• Keep your Git installation updated. Outdated versions may contain security vulnerabilities.
• Record every command output in your lab log as you go; do not reconstruct it from memory after the fact.