docker-minecraft-server/scripts/start-deployPurpur

#!/bin/bash
set -euo pipefail
IFS=$'\n\t'

# shellcheck source=start-utils
. "${SCRIPTS:-/}start-utils"
isDebugging && set -x

if [[ $PURPUR_DOWNLOAD_URL ]]; then
  export SERVER=$(getFilenameFromUrl "${PURPUR_DOWNLOAD_URL}")

  if [ -f "$SERVER" ]; then
    zarg=(-z "$SERVER")
  fi

  echo "Preparing custom Purpur jar from $PURPUR_DOWNLOAD_URL"

  curl -fsSL -o "$SERVER" "${zarg[@]}" "${PURPUR_DOWNLOAD_URL}"
else
  : "${VANILLA_VERSION:?}"
  : "${PURPUR_BUILD:=LATEST}"
  : "${FORCE_REDOWNLOAD:=false}"

  if [[ ${PURPUR_BUILD} == LATEST ]]; then
    if ! PURPUR_BUILD=$(get --json-path=".builds.latest" "https://api.purpurmc.org/v2/purpur/${VANILLA_VERSION}"); then
      log "ERROR: Failed to locate a Purpur build for ${VANILLA_VERSION}."
      log "       Please check if a download is available at https://purpur.pl3x.net/downloads/"
      exit 1
    fi
  fi

  export SERVER="purpur-${VANILLA_VERSION}-${PURPUR_BUILD}.jar"

  log "Removing old Purpur versions ..."
  shopt -s nullglob
  for f in purpur-*.jar; do
    [[ $f != "$SERVER" ]] && rm "$f"
  done

  if [ ! -f "$SERVER" ] || isTrue "$FORCE_REDOWNLOAD"; then
      downloadUrl="https://api.purpurmc.org/v2/purpur/${VANILLA_VERSION}/${PURPUR_BUILD}/download"
      log "Downloading Purpur from $downloadUrl ..."
      if ! get -o "$SERVER" "$downloadUrl"; then
        log "ERROR: failed to download from $downloadUrl (status=$?)"
        exit 3
      fi
  fi
fi

# Normalize on Spigot for later operations
export FAMILY=SPIGOT

exec "${SCRIPTS:-/}start-spiget" "$@"