Bash script to upgrade your Ghost blog installation to the latest version

upgrade_ghost.sh

#!/bin/bash
# Make sure only root can run our script
if [[ ${EUID} -ne 0 ]]; then  
  echo "This script must be run as root" 1>&2
  exit 1
fi

if [[ $# -eq 0 ]]; then  
  echo "Usage:"
  echo "    $0 <systemd|sysv>"
  echo -e "\n systemd : use systemd/systemctl to stop/start services"
  echo " sysv    : use /etc/init.d syvs init system to stop/start services"
fi

GHOST_PARENT=/var/www  
OLD_PWD=$(pwd)

case "$1" in  
   systemd)
     INIT_START="sudo systemctl start ghost.service"
     INIT_STOP ="sudo systemctl stop ghost.service"
     ;;
   sysv)
     INIT_START="sudo service ghost start"
     INIT_STOP ="sudo service ghost stop"
     ;;
esac

cd ${GHOST_PARENT}

# Get current Ghost version
OLD_VERSION=$(node -pe "JSON.parse(require('fs').readFileSync('/dev/stdin').toString()).version" < ghost/package.json)

echo "Upgrading Ghost"  
rm -fr ghost-latest
echo -n "Fetching ... "  
curl -LOk https://ghost.org/zip/ghost-latest.zip > upgrade.log 2>&1 || exit  
echo "Unzipping ..."  
unzip ghost-latest.zip -d ghost-latest >> upgrade.log 2>&1 || exit

# Get new Ghost version
NEW_VERSION=$(node -pe "JSON.parse(require('fs').readFileSync('/dev/stdin').toString()).version" < ghost-latest/package.json)

echo "Upgrading from ${OLD_VERSION} to ${NEW_VERSION}.  Please wait ..."

# Stop Ghost
${INIT_STOP}

# Backup the current version core files
mv -v ghost/core ghost-${OLD_VERSION}-core || exit

# Update with new files
cp -v ghost-latest/{*.js,*.json,*.md,LICENSE} ghost/ || exit  
cp -R -v ghost-latest/core ghost/ || exit  
cp -R -v ghost-latest/content/themes/casper ghost/content/themes || exit  
cd ghost

# Update nodejs modules as required
npm install --production

# Fix permissions
chown -R ghost:www-data ./*

# Restart Ghost
${INIT_START}

cd ${OLD_PWD}