GitHub Setup Using SSH (Linux)

This guide explains how to install Git, generate an SSH key, connect it to GitHub, and use GitHub securely without passwords.

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1. Install Git

Update system packages and install Git:

sudo apt update
sudo apt install git -y

Verify installation:

git --version

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2. Configure Git (First Time Only)

Set your GitHub username and email:

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

Verify configuration:

git config --global --list

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3. Generate SSH Key for GitHub

Generate a new ED25519 SSH key:

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

Press Enter to accept default location: ~/.ssh/id_ed25519

(Optional) Set a passphrase for extra security.

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4. Start SSH Agent and Add Key

Start the SSH agent:

eval "$(ssh-agent -s)"

Add the private key (do NOT add .pub):

ssh-add ~/.ssh/id_ed25519

Verify key is loaded:

ssh-add -l

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5. Add SSH Key to GitHub

Copy the public key:

cat ~/.ssh/id_ed25519.pub

1. Go to GitHub → Settings → SSH and GPG keys
2. Click New SSH key
3. Add a title (example: Linux-PC)
4. Paste the public key
5. Click Add SSH key

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6. Test GitHub SSH Connection

Test authentication:

ssh -T git@github.com

Expected output:

Hi ! You've successfully authenticated, but GitHub does not provide shell access.

This message means SSH is working correctly.

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7. Clone or Connect a Repository Using SSH

Clone a repository:

git clone git@github.com:USERNAME/REPOSITORY.git

OR change existing repo from HTTPS to SSH:

git remote set-url origin git@github.com:USERNAME/REPOSITORY.git

Check remote URL:

git remote -v

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8. Basic Git Workflow

git status
git add .
git commit -m "Initial commit"
git push origin main
git pull

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9. Recommended SSH Configuration (Optional)

Create SSH config file:

nano ~/.ssh/config

Add:

Host github.com
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_ed25519
    IdentitiesOnly yes

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10. Make SSH Default for GitHub (Optional)

git config --global url."git@github.com:".insteadOf "https://github.com/"

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Done

Your GitHub SSH setup is complete and ready for development, CI/CD, and automation.

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