ops: prepare docker critical events watcher

2026-06-05 22:25:23 +02:00
parent bc3ecad45a
commit 2f3d184a3b
6 changed files with 225 additions and 9 deletions
@@ -0,0 +1,142 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+BASE_DIR="${BASE_DIR:-/mnt/user/services/posture-check}"
+WATCHER_SCRIPT="${WATCHER_SCRIPT:-/mnt/user/services/homelab-infra/services/posture-check/docker-critical-events.sh}"
+PID_FILE="${PID_FILE:-$BASE_DIR/docker-critical-events.pid}"
+OUT_FILE="${OUT_FILE:-$BASE_DIR/docker-critical-events.out}"
+EVENT_LOG="${EVENT_LOG:-$BASE_DIR/docker-critical-events-last.log}"
+NTFY_SCRIPT="${NTFY_SCRIPT:-/mnt/user/services/homelab-infra/ops/restore-tests/send-ntfy.sh}"
+NTFY_TOPIC="${NTFY_TOPIC:-homelab-alerts}"
+
+usage() {
+  cat >&2 <<EOF
+Usage: $0 start|stop|restart|status|smoke
+
+start    Start Docker critical-events watcher in the background.
+stop     Stop the watcher by pidfile.
+restart  Stop and start the watcher.
+status   Print watcher status and recent log tail.
+smoke    Send one ntfy test message through the same alert path.
+EOF
+}
+
+is_running() {
+  [ -s "$PID_FILE" ] || return 1
+  local pid
+  pid="$(cat "$PID_FILE")"
+  [ -n "$pid" ] || return 1
+  kill -0 "$pid" >/dev/null 2>&1
+}
+
+start_watcher() {
+  mkdir -p "$BASE_DIR"
+
+  if is_running; then
+    echo "docker-critical-events watcher already running (pid $(cat "$PID_FILE"))"
+    return 0
+  fi
+
+  if [ ! -r "$WATCHER_SCRIPT" ]; then
+    echo "Watcher script not readable: $WATCHER_SCRIPT" >&2
+    return 1
+  fi
+
+  NTFY_SCRIPT="$NTFY_SCRIPT" \
+  NTFY_TOPIC="$NTFY_TOPIC" \
+  OUTPUT_PATH="$EVENT_LOG" \
+  nohup bash "$WATCHER_SCRIPT" >"$OUT_FILE" 2>&1 </dev/null &
+
+  echo "$!" > "$PID_FILE"
+  sleep 1
+
+  if is_running; then
+    echo "docker-critical-events watcher started (pid $(cat "$PID_FILE"))"
+  else
+    echo "docker-critical-events watcher failed to stay running; see $OUT_FILE" >&2
+    return 1
+  fi
+}
+
+stop_watcher() {
+  if ! is_running; then
+    rm -f "$PID_FILE"
+    echo "docker-critical-events watcher is not running"
+    return 0
+  fi
+
+  local pid
+  pid="$(cat "$PID_FILE")"
+  kill "$pid" >/dev/null 2>&1 || true
+  sleep 1
+
+  if kill -0 "$pid" >/dev/null 2>&1; then
+    echo "watcher still running after SIGTERM; sending SIGKILL"
+    kill -9 "$pid" >/dev/null 2>&1 || true
+  fi
+
+  rm -f "$PID_FILE"
+  echo "docker-critical-events watcher stopped"
+}
+
+status_watcher() {
+  if is_running; then
+    echo "status=running pid=$(cat "$PID_FILE")"
+  else
+    echo "status=stopped"
+    [ -e "$PID_FILE" ] && echo "stale_pidfile=$PID_FILE"
+  fi
+
+  echo "watcher_script=$WATCHER_SCRIPT"
+  echo "event_log=$EVENT_LOG"
+  echo "out_file=$OUT_FILE"
+
+  if [ -s "$EVENT_LOG" ]; then
+    echo
+    echo "Recent critical events:"
+    tail -n 20 "$EVENT_LOG"
+  fi
+
+  if [ -s "$OUT_FILE" ]; then
+    echo
+    echo "Recent watcher output:"
+    tail -n 20 "$OUT_FILE"
+  fi
+}
+
+smoke_ntfy() {
+  if [ ! -r "$NTFY_SCRIPT" ]; then
+    echo "ntfy helper not readable: $NTFY_SCRIPT" >&2
+    return 1
+  fi
+
+  bash "$NTFY_SCRIPT" \
+    "$NTFY_TOPIC" \
+    "Docker critical watcher smoke" \
+    "Smoke test from $(hostname) at $(date -Iseconds). No container was stopped." \
+    default
+  echo "smoke notification sent to $NTFY_TOPIC"
+}
+
+case "${1:-}" in
+  start)
+    start_watcher
+    ;;
+  stop)
+    stop_watcher
+    ;;
+  restart)
+    stop_watcher
+    start_watcher
+    ;;
+  status)
+    status_watcher
+    ;;
+  smoke)
+    smoke_ntfy
+    ;;
+  *)
+    usage
+    exit 2
+    ;;
+esac