minecraft-ntfy-notify/mc-ntfy-notify.v1.sh

#!/usr/bin/env bash
#!/bin/bash
# Beschreibung: Minecraft → ntfy Notifier (Join/Leave + optional Up/Down) mit Cron-safe Locking
# Autor:        Patrick Asmus
# Web:          https://www.cleveradmin.de
# Repository:   https://git.techniverse.net/scriptos/minecraft-ntfy-notify
# Version:      1.5
# Datum:        18.09.2025
# Modifikation: Tags entfernt; Titel statisch (kein Join/Leave im Titel); DNS:Port im Body ergänzt
#####################################################
set -euo pipefail
export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"

# .env laden: bevorzugt ENV_FILE, sonst ./.env
if [[ -n "${ENV_FILE:-}" && -f "${ENV_FILE}" ]]; then
  set -a; . "${ENV_FILE}"; set +a
elif [[ -f "${SCRIPT_DIR}/.env" ]]; then
  set -a; . "${SCRIPT_DIR}/.env"; set +a
fi

# ===== Konfiguration via ENV =====
MC_HOST="${MC_HOST:-127.0.0.1}"
RCON_PORT="${RCON_PORT:-25575}"
RCON_PASSWORD="${RCON_PASSWORD:-changeme}"

POLL_SECONDS="${POLL_SECONDS:-10}"
ANNOUNCE_SERVER_UPDOWN="${ANNOUNCE_SERVER_UPDOWN:-true}"

# ntfy
NTFY_SERVER="${NTFY_SERVER:-}"
NTFY_TOPIC="${NTFY_TOPIC:-}"
NTFY_TOKEN="${NTFY_TOKEN:-}"
NTFY_TITLE_PREFIX="${NTFY_TITLE_PREFIX:-Minecraft}"
NTFY_PRIORITY_JOIN="${NTFY_PRIORITY_JOIN:-3}"
NTFY_PRIORITY_LEAVE="${NTFY_PRIORITY_LEAVE:-3}"
NTFY_PRIORITY_UP="${NTFY_PRIORITY_UP:-4}"
NTFY_PRIORITY_DOWN="${NTFY_PRIORITY_DOWN:-5}"
NTFY_MARKDOWN="${NTFY_MARKDOWN:-false}"

# Optionaler Anzeigename (nur informativ)
SERVER_NAME="${SERVER_NAME:-}"

# Lock & State je Instanz (Host:Port:Topic)
LOCK_KEY="$(printf '%s' "${MC_HOST}_${RCON_PORT}_${NTFY_TOPIC}" | tr -c 'A-Za-z0-9._-' '_')"
STATE_DIR="${STATE_DIR:-${SCRIPT_DIR}/state.${LOCK_KEY}}"
STATE_PLAYERS="${STATE_DIR}/players.prev"
STATE_UP="${STATE_DIR}/server_up.prev"
RUN_DIR="${RUN_DIR:-${STATE_DIR}}"
LOCK_DIR="${RUN_DIR}/lock.${LOCK_KEY}"
PID_FILE="${LOCK_DIR}/pid"
RUN_MARK="${RUN_DIR}/running.${LOCK_KEY}"

DEBUG="${DEBUG:-false}"

# ===== Helpers =====
die() { echo "ERROR: $*" >&2; exit 1; }
need_bin() { command -v "$1" >/dev/null 2>&1 || die "Benötigtes Tool fehlt: $1"; }
dbg() { [[ "$DEBUG" == "true" ]] && echo "DBG: $*" >&2 || true; }

cleanup() {
  rm -f "$RUN_MARK" "$PID_FILE" 2>/dev/null || true
  rmdir "$LOCK_DIR" 2>/dev/null || true
}

acquire_lock() {
  mkdir -p "$RUN_DIR"
  if mkdir "$LOCK_DIR" 2>/dev/null; then
    echo "$$" > "$PID_FILE"
    trap cleanup EXIT INT TERM
  else
    if [[ -f "$PID_FILE" ]]; then
      oldpid="$(cat "$PID_FILE" 2>/dev/null || true)"
      if [[ -n "${oldpid:-}" ]] && kill -0 "$oldpid" 2>/dev/null; then
        dbg "Bereits laufend (PID $oldpid), beende."
        exit 0
      fi
    fi
    rm -rf "$LOCK_DIR" 2>/dev/null || true
    mkdir "$LOCK_DIR" 2>/dev/null || die "Konnte Lock nicht übernehmen: ${LOCK_DIR}"
    echo "$$" > "$PID_FILE"
    trap cleanup EXIT INT TERM
  fi
}

ntfy_notify() {
  # ntfy_notify "Titel" "Nachricht" PRIORITY
  local title="$1" body="$2" priority="$3"
  [[ -z "$NTFY_SERVER" || -z "$NTFY_TOPIC" ]] && { echo "ntfy Server/Topic fehlt – skip"; return 1; }
  local url="${NTFY_SERVER%/}/${NTFY_TOPIC}"
  local args=(-sS -X POST "$url" -H "Title: ${title}" -H "Priority: ${priority}")
  [[ "$NTFY_MARKDOWN" == "true" ]] && args+=(-H "Markdown: yes")
  [[ -n "$NTFY_TOKEN" ]] && args+=(-H "Authorization: Bearer ${NTFY_TOKEN}")
  curl "${args[@]}" --data-raw "$body" >/dev/null 2>&1 || return 1
  return 0
}

ensure_state() {
  mkdir -p "$STATE_DIR"
  touch "$STATE_PLAYERS"
  [[ -f "$STATE_UP" ]] || echo "unknown" >"$STATE_UP"
}

# ANSI- und MC-Farbcodes entfernen
sanitize() {
  sed -E $'s/\x1B\\[[0-9;]*[A-Za-z]//g' \
  | sed -E 's/§[0-9A-FK-ORa-fk-or]//g' \
  | tr -d '\r' \
  | sed -E 's/[\x00-\x1F\x7F]//g'
}

get_players() {
  local out
  if ! out=$(mcrcon -H "$MC_HOST" -P "$RCON_PORT" -p "$RCON_PASSWORD" "list" 2>/dev/null); then
    return 1
  fi
  dbg "RAW: $out"
  out="$(printf '%s' "$out" | sanitize)"
  if ! grep -q "players online:" <<<"$out"; then
    return 0
  fi
  local names="${out#*:}"
  names="$(echo "$names" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')"
  if [[ -z "$names" ]]; then
    return 0
  fi
  printf '%s\n' "$names" \
    | tr ',' '\n' \
    | sed 's/^[[:space:]]*//;s/[[:space:]]*$//' \
    | sed '/^$/d' \
    | LC_ALL=C sort -u
  return 0
}

# ===== Checks & Lock =====
need_bin curl
need_bin mcrcon
[[ -n "${NTFY_SERVER}" && -n "${NTFY_TOPIC}" ]] || die "NTFY_SERVER/NTFY_TOPIC nicht gesetzt"
ensure_state
acquire_lock

echo "Starte Polling ${MC_HOST}:${RCON_PORT} -> ntfy ${NTFY_SERVER}/${NTFY_TOPIC} (PID $$)"
prev_up="$(cat "$STATE_UP")"

# ===== Main Loop =====
while :; do
  date -Iseconds > "$RUN_MARK"; echo "$$" >> "$RUN_MARK"

  tmp_players="$(mktemp)"
  if get_players >"$tmp_players"; then
    server_up="true"
  else
    server_up="false"
    : >"$tmp_players"
  fi

  if [[ "$ANNOUNCE_SERVER_UPDOWN" == "true" && "$prev_up" != "unknown" && "$server_up" != "$prev_up" ]]; then
    if [[ "$server_up" == "true" ]]; then
      ntfy_notify "${NTFY_TITLE_PREFIX}" \
                  "Server ist wieder erreichbar (${MC_HOST}:${RCON_PORT})." \
                  "$NTFY_PRIORITY_UP" || true
    else
      ntfy_notify "${NTFY_TITLE_PREFIX}" \
                  "Server ist nicht erreichbar (${MC_HOST}:${RCON_PORT})." \
                  "$NTFY_PRIORITY_DOWN" || true
    fi
  fi

  if [[ "$server_up" == "true" ]]; then
    LC_ALL=C sort -u "$STATE_PLAYERS" -o "$STATE_PLAYERS"
    joined="$(comm -13 "$STATE_PLAYERS" "$tmp_players" || true)"
    left="$(comm -23 "$STATE_PLAYERS" "$tmp_players" || true)"

    if [[ -n "$joined" ]]; then
      while IFS= read -r name; do
        [[ -z "$name" ]] && continue
        ntfy_notify "${NTFY_TITLE_PREFIX}" \
                    "Player \"${name}\" ist beigetreten. Server: ${MC_HOST}:${RCON_PORT}" \
                    "$NTFY_PRIORITY_JOIN" || true
      done <<<"$joined"
    fi
    if [[ -n "$left" ]]; then
      while IFS= read -r name; do
        [[ -z "$name" ]] && continue
        ntfy_notify "${NTFY_TITLE_PREFIX}" \
                    "Player \"${name}\" hat den Server verlassen. Server: ${MC_HOST}:${RCON_PORT}" \
                    "$NTFY_PRIORITY_LEAVE" || true
      done <<<"$left"
    fi

    mv "$tmp_players" "$STATE_PLAYERS"
  else
    rm -f "$tmp_players"
  fi

  echo -n "$server_up" >"$STATE_UP"
  prev_up="$server_up"
  sleep "$POLL_SECONDS"
done