Add local domains in MacOS

local-domain

#!/bin/bash

# A script to add or remove local domains from the /etc/hosts file and
# optionally manage locally-trusted SSL certificates using mkcert.

# --- Configuration ---
HOSTS_FILE="/etc/hosts"
IP_ADDRESS="127.0.0.1"

# --- Help Function ---
show_help() {
  echo "Usage: sudo ./local-domain <command> [options] <domain>"
  echo ""
  echo "Commands:"
  echo "  add (default)    Adds a domain to your /etc/hosts file."
  echo "  remove           Removes a domain from your /etc/hosts file."
  echo "  help, -h, --help Show this help message."
  echo ""
  echo "Options for 'add':"
  echo "  --https          Generate a locally-trusted SSL certificate for the domain."
  echo "                   Certs are saved in 'certs/<domain>/'."
  echo ""
  echo "Options for 'remove':"
  echo "  --with-certs     Also remove the associated SSL certificate directory."
  echo ""
  echo "Examples:"
  echo "  # Add a domain (add command is optional)"
  echo "  sudo ./local-domain my-app.local"
  echo "  sudo ./local-domain add my-app.local"
  echo ""
  echo "  # Add a domain and generate an SSL certificate"
  echo "  sudo ./local-domain add --https my-app.local"
  echo ""
  echo "  # Remove a domain"
  echo "  sudo ./local-domain remove my-app.local"
  echo ""
  echo "  # Remove a domain and its certificates"
  echo "  sudo ./local-domain remove --with-certs my-app.local"
}

# --- Command and Argument Parsing ---
COMMAND="add" # Default command
if [[ "$1" == "add" || "$1" == "remove" || "$1" == "help" || "$1" == "-h" || "$1" == "--help" ]]; then
  COMMAND=$1
  shift
fi

if [[ "$COMMAND" == "help" || "$COMMAND" == "-h" || "$COMMAND" == "--help" ]]; then
  show_help
  exit 0
fi

HTTPS_ENABLED=false
WITH_CERTS=false
DOMAIN=""

while (( "$#" )); do
  case "$1" in
    --https)
      HTTPS_ENABLED=true
      shift
      ;;
    --with-certs)
      WITH_CERTS=true
      shift
      ;;
    -*)
      echo "Error: Unsupported flag $1" >&2
      show_help
      exit 1
      ;;
    *)
      if [ -n "$DOMAIN" ]; then
        echo "Error: Please specify only one domain." >&2
        show_help
        exit 1
      fi
      DOMAIN=$1
      shift
      ;;
  esac
done

# --- Script Logic ---

# 1. Check for root privileges
if [ "$EUID" -ne 0 ]; then
  echo "❌ This script must be run with sudo."
  echo "   Run './local-domain --help' for usage instructions."
  exit 1
fi

# 2. Check for domain argument
if [ -z "$DOMAIN" ]; then
  echo "❌ No domain provided for command '$COMMAND'."
  show_help
  exit 1
fi

# --- Function Definitions ---

add_domain() {
  # Handle HTTPS setup if requested
  if [ "$HTTPS_ENABLED" = true ]; then
    if ! command -v mkcert &> /dev/null; then
      echo "❌ 'mkcert' is not installed. Please install it first (e.g., 'brew install mkcert')."
      exit 1
    fi
    ORIGINAL_USER=$SUDO_USER
    if [ -z "$ORIGINAL_USER" ]; then
        echo "❌ Could not determine the original user from \$SUDO_USER. Cannot run mkcert."
        exit 1
    fi
    echo "🚀 HTTPS option enabled. Generating certificate for '$DOMAIN'..."
    echo "   Ensuring local CA is installed for user '$ORIGINAL_USER'..."
    sudo -u "$ORIGINAL_USER" mkcert -install
    CERT_DIR="certs/$DOMAIN"
    echo "   Creating certificate directory: $CERT_DIR"
    sudo -u "$ORIGINAL_USER" mkdir -p "$CERT_DIR"
    echo "   Generating certificate and key..."
    sudo -u "$ORIGINAL_USER" mkcert -key-file "$CERT_DIR/key.pem" -cert-file "$CERT_DIR/cert.pem" "$DOMAIN"
    echo "✅ Certificate and key created in '$CERT_DIR'."
  fi

  # Add domain to hosts file
  if grep -q -E "^\s*$IP_ADDRESS\s+.*\b$DOMAIN\b" "$HOSTS_FILE"; then
    echo "✅ Domain '$DOMAIN' already exists in $HOSTS_FILE."
  else
    echo "Editing $HOSTS_FILE to add '$DOMAIN'..."
    echo "$IP_ADDRESS $DOMAIN" >> "$HOSTS_FILE"
    echo "✅ Domain '$DOMAIN' added to $HOSTS_FILE."
  fi
}

remove_domain() {
  # Remove domain from hosts file
  if grep -q -E "^\s*$IP_ADDRESS\s+.*\b$DOMAIN\b" "$HOSTS_FILE"; then
    echo "Editing $HOSTS_FILE to remove '$DOMAIN'..."
    # Use sed to delete the line containing the domain. Creates a backup file.
    sed -i.bak "/\b$DOMAIN\b/d" "$HOSTS_FILE"
    echo "✅ Domain '$DOMAIN' removed from $HOSTS_FILE."
  else
    echo "ℹ️ Domain '$DOMAIN' not found in $HOSTS_FILE."
  fi

  # Handle certificate removal if requested
  if [ "$WITH_CERTS" = true ]; then
    CERT_DIR="certs/$DOMAIN"
    if [ -d "$CERT_DIR" ]; then
      echo "Removing certificate directory: $CERT_DIR"
      rm -rf "$CERT_DIR"
      echo "✅ Certificate directory removed."
    else
      echo "ℹ️ Certificate directory '$CERT_DIR' not found."
    fi
  fi
}

# --- Main Execution ---

case "$COMMAND" in
  add)
    add_domain
    ;;
  remove)
    remove_domain
    ;;
esac

# Flush DNS cache
echo "Flushing DNS cache..."
dscacheutil -flushcache >/dev/null 2>&1
killall -HUP mDNSResponder >/dev/null 2>&1

echo "✅ Successfully processed domain '$DOMAIN'."
exit 0