github-setup-deploy-key

#!/bin/bash

set -e

# Parse repository URL and extract username/reponame
parse_repo_info() {
    local url="$1"

    # Handle git@github.com:username/repo.git format
    if [[ "$url" =~ ^git@github\.com:(.*)\.git$ ]]; then
        echo "${BASH_REMATCH[1]}"
    # Handle https://github.com/username/repo.git format
    elif [[ "$url" =~ ^https://github\.com/(.*)\.git$ ]]; then
        echo "${BASH_REMATCH[1]}"
    else
        echo "Error: Unsupported URL format. Expected: git@github.com:user/repo.git or https://github.com/user/repo.git" >&2
        exit 1
    fi
}

# Generate SSH key for repository
generate_key() {
    local repo_path="$1"
    local key_name="${repo_path//\//_}_deploy_key"
    local key_path="$HOME/.ssh/$key_name"

    if [[ -f "$key_path" ]]; then
        echo "Warning: SSH key already exists at $key_path"
        return 0
    fi

    echo "Generating SSH key for $repo_path..."
    ssh-keygen -t rsa -b 4096 -f "$key_path" -C "$repo_path deploy key" -N ""
    echo "SSH key generated: $key_path"
}

# Add SSH config entry
add_ssh_config() {
    local repo_path="$1"
    local key_name="${repo_path//\//_}_deploy_key"
    local host_alias="github.com-${repo_path//\//_}"

    local config_entry="
Host $host_alias
    HostName github.com
    User git
    IdentityFile ~/.ssh/$key_name
    IdentitiesOnly yes"

    echo "Adding SSH config entry for $host_alias..."
    echo "$config_entry" >> "$HOME/.ssh/config"
    echo "SSH config updated."
}

# Display public key and instructions
show_instructions() {
    local repo_path="$1"
    local key_name="${repo_path//\//_}_deploy_key"
    local public_key_path="$HOME/.ssh/$key_name.pub"
    local host_alias="github.com-${repo_path//\//_}"

    echo ""
    echo "=== SETUP INSTRUCTIONS ==="
    echo "1. Add deploy key at: https://github.com/$repo_path/settings/keys"
    echo "   Copy the public key below and paste it in the deploy key form:"
    echo ""
    cat "$public_key_path"
    echo ""
    echo "2. Clone the repository using this command:"
    echo "   git clone $host_alias:$repo_path.git"
    echo ""
    echo "3. If you already have the repository cloned, update its remote URL:"
    echo "   cd /path/to/repo"
    echo "   git remote set-url origin $host_alias:$repo_path.git"
    echo ""
}

main() {
    if [[ $# -ne 1 ]]; then
        echo "Usage: $0 <repository-url>"
        echo "Example: $0 git@github.com:user/reponame.git"
        exit 1
    fi

    local repo_url="$1"
    local repo_path
    repo_path=$(parse_repo_info "$repo_url")

    echo "Setting up deploy key for repository: $repo_path"

    generate_key "$repo_path"
    add_ssh_config "$repo_path"
    show_instructions "$repo_path"

    echo "Setup complete! Follow the instructions above to complete the configuration."
}

main "$@"