Update Minecraft FTB/ATM6 docker containers to the latest version

update-version.sh

#!/bin/bash

if [ $# -eq 0 ]
  then
    echo "No arguments supplied. Must specify the version for the upgrade."
    exit 1
fi

new_version=$1

if test -f "./data/version.txt"; then
  version=$(<./data/version.txt)  
else
  echo "No previous version found. Create ./data/version.txt with current version number."
  exit 1
fi


modpack_file=./modpacks/SIMPLE-SERVER-FILES-$new_version.zip
if test -f "$modpack_file"; then
  echo "New modpack found: $modpack_file"
else
  echo "Unable to locate modpack. Make sure the latest version is stored in $modpack_file".
  exit 1
fi

echo "Updating from $version to $new_version."
data_pattern=./data/FeedTheBeast/SIMPLE-SERVER-FILES
old_data=$data_pattern-$version

# Locate the name of the world for this server
input=$old_data/server.properties
level_name=world
while IFS='=' read -r field value
do
  #echo "name: $field; value: $value"
  if [ "$field" = "level-name" ]; then
    level_name=$value
  fi
done < $input

echo "Minecraft world level name: $level_name"

# Create a backup of the existing server
echo "Archiving $version..."
tar -zcf archive/backup-$version.tar.gz ./data

# Move configuration files to a temp folder
mkdir -p ./config
echo "Saving configuration files..."
cp $old_data/ops.json $old_data/whitelist.json $old_data/server.properties ./config/

echo "Saving world $level_name files..."
cp -r $old_data/$level_name ./config/$level_name

# Remove previous server data folder
rm -rf ./data

# Recreate data folder and copy saved files
new_data=$data_pattern-$new_version
mkdir -p $new_data
mv ./config/ops.json ./config/whitelist.json ./config/server.properties $new_data/
mv ./config/$level_name $new_data/$level_name

rm -r ./config

# Rewrite docker-compose.yaml file to use the new modpack version
echo $new_version >| ./data/version.txt
sed -i "s/SIMPLE-SERVER-FILES-$version.zip/SIMPLE-SERVER-FILES-$new_version.zip/" docker-compose.yaml

echo "Ready to relaunch server and finalize update."
echo "To get started, run docker-compose up -d"