docker-minecraft-server/scripts/start-utils

#!/bin/bash

function join_by() {
  local d=$1
  shift
  echo -n "$1"
  shift
  printf "%s" "${@/#/$d}"
}

function isURL() {
  local value=$1

  if [[ ${value:0:8} == "https://" || ${value:0:7} == "http://" || ${value:0:6} == "ftp://" ]]; then
    return 0
  else
    return 1
  fi
}

function isValidFileURL() {
  suffix=${1:?Missing required suffix arg}
  url=${2:?Missing required url arg}

  [[ "$url" == http*://*.${suffix} || "$url" == http*://*.${suffix}\?* ]]
}

function resolveEffectiveUrl() {
  url="${1:?Missing required url argument}"
  if ! curl -Ls -o /dev/null -w %{url_effective} "$url"; then
    log "ERROR failed to resolve effective URL from $url"
    exit 2
  fi
}

function getFilenameFromUrl() {
  url="${1:?Missing required url argument}"
  strippedOfQuery="${url%\?*}"
  basename "$strippedOfQuery"
}

function isTrue() {
  local value=${1,,}

  result=

  case ${value} in
  true | on)
    result=0
    ;;
  *)
    result=1
    ;;
  esac

  return ${result}
}

function isDebugging() {
  if isTrue "${DEBUG:-false}"; then
    return 0
  else
    return 1
  fi
}

function handleDebugMode() {
  if isDebugging; then
    set -x
    extraCurlArgs=(-v)
  fi
}

function debug() {
  if isDebugging; then
    log "DEBUG: $*"
  fi
}

function logn() {
  echo -n "[init] $*"
}

function log() {
  echo "[init] $*"
}

function logAutopause() {
  echo "[Autopause loop] $*"
}

function logAutopauseAction() {
  echo "[$(date -Iseconds)] [Autopause] $*"
}

function normalizeMemSize() {
  local scale=1
  case ${1,,} in
  *k)
    scale=1024
    ;;
  *m)
    scale=1048576
    ;;
  *g)
    scale=1073741824
    ;;
  esac

  val=${1:0:-1}
  echo $((val * scale))
}

function versionLessThan() {
  mc-image-helper compare-versions "${VANILLA_VERSION}" lt "${1?}"
}

requireVar() {
  if [ ! -v $1 ]; then
    log "ERROR: $1 is required to be set"
    exit 1
  fi
  if [ -z "${!1}" ]; then
    log "ERROR: $1 is required to be set"
    exit 1
  fi
}

requireEnum() {
  var=${1?}
  shift

  for allowed in $*; do
    if [[ ${!var} = $allowed ]]; then
      return 0
    fi
  done

  log "ERROR: $var must be set to one of $*"
#  exit 1
}

function writeEula() {
  if ! echo "# Generated via Docker
# $(date)
eula=${EULA,,}
" >/data/eula.txt; then
    log "ERROR: unable to write eula to /data. Please make sure attached directory is writable by uid=${UID}"
    exit 2
  fi
}

function removeOldMods {
  if [ -d "$1" ]; then
    find "$1" -mindepth 1 -maxdepth ${REMOVE_OLD_MODS_DEPTH:-16} -wholename "${REMOVE_OLD_MODS_INCLUDE:-*}" -not -wholename "${REMOVE_OLD_MODS_EXCLUDE:-}" -delete
  fi
}

function get() {
  local flags=()
  if isTrue "${DEBUG_GET:-false}"; then
    flags+=("--debug")
  fi
  mc-image-helper "${flags[@]}" get "$@"
}

function isFamily() {
  for f in "${@}"; do
    if [[ $FAMILY == "$f" ]]; then
      return 0
    fi
  done
  return 1
}