Efficient Local Directory Synchronization with rsync

#!/bin/bash

# Source directory (e.g., your build output)
SOURCE_DIR="./dist/"

# Destination directory (e.g., your local web server's document root or a backup location)
DEST_DIR="/var/www/html/my-app/"

# --- Configuration End ---

# Ensure source directory exists
if [ ! -d "$SOURCE_DIR" ]; then
  echo "Error: Source directory '$SOURCE_DIR' does not exist. Aborting."
  exit 1
fi

# Ensure destination directory exists, or attempt to create it
if [ ! -d "$DEST_DIR" ]; then
  echo "Destination directory '$DEST_DIR' does not exist. Attempting to create..."
  mkdir -p "$DEST_DIR"
  if [ $? -ne 0 ]; then
    echo "Error: Failed to create destination directory '$DEST_DIR'. Check permissions."
    exit 1
  fi
fi

echo "Synchronizing files from '$SOURCE_DIR' to '$DEST_DIR' ..."

# rsync command for synchronization:
# -a, --archive: archive mode; equals -rlptgoD (no -H,-A,-X)
# -v, --verbose: increase verbosity
# -z, --compress: compress file data during the transfer
# --delete: delete extraneous files from destination dirs (not in source)
# --exclude: exclude specific files/patterns (e.g., node_modules, .git)
# --progress: show progress during transfer
# --dry-run: perform a trial run with no changes made (useful for testing)

# Example with --dry-run for testing:
# rsync -avz --delete --dry-run "$SOURCE_DIR" "$DEST_DIR"

rsync -avz --delete \
      --exclude='node_modules/' \
      --exclude='.git/' \
      --exclude='.env' \
      "$SOURCE_DIR" "$DEST_DIR"

# Check the exit status of rsync
if [ $? -eq 0 ]; then
  echo "
Synchronization successful!"
else
  echo "
Synchronization failed with errors. Please check the output above."
  exit 1
fi

exit 0