Add Loki Alloy logging baseline

services/posture-check/docker-critical-events.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+NTFY_SCRIPT="${NTFY_SCRIPT:-/mnt/user/services/homelab-infra/ops/restore-tests/send-ntfy.sh}"
+NTFY_TOPIC="${NTFY_TOPIC:-kallilab-critical}"
+SEND_NTFY="${SEND_NTFY:-1}"
+OUTPUT_PATH="${OUTPUT_PATH:-/mnt/user/services/posture-check/docker-critical-events-last.log}"
+EVENT_FILTERS="${EVENT_FILTERS:---filter event=die --filter event=oom --filter event=kill}"
+
+mkdir -p "$(dirname "$OUTPUT_PATH")"
+
+send_event() {
+  local line="$1"
+  local timestamp
+  timestamp="$(date -Iseconds)"
+
+  printf '%s %s\n' "$timestamp" "$line" | tee -a "$OUTPUT_PATH" >/dev/null
+
+  if [ "$SEND_NTFY" = "1" ] && [ -x "$NTFY_SCRIPT" ]; then
+    "$NTFY_SCRIPT" "$NTFY_TOPIC" "Docker critical event" "$line" high || true
+  fi
+}
+
+if ! command -v docker >/dev/null 2>&1; then
+  echo "docker command not found" >&2
+  exit 127
+fi
+
+# shellcheck disable=SC2086
+docker events $EVENT_FILTERS --format '{{json .}}' | while IFS= read -r event; do
+  [ -n "$event" ] || continue
+  send_event "$event"
+done