#!/usr/bin/env bash
# Wrapper invoked by cron on docker-1/docker-2/docker-3 to rotate the shared
# Traefik access/error logs (see traefik-logs.conf for the "full why").
#
# Because /volume1/docker/traefik/logs is the SAME physical CephFS path on
# all three nodes, and cron on all three nodes runs this independently, we
# use a shared flock (also on the CephFS mount, so it's visible cluster-wide)
# to guarantee only one node actually executes logrotate at a time, and a
# SHARED state file so whichever node runs it knows the true last-rotated
# time regardless of which node rotated it last. If a node is down, the
# other two still cover the schedule -- none of this relies on a specific
# node being up.
set -euo pipefail

LOCK_DIR="/volume1/docker/traefik/logrotate-state"
LOCK_FILE="$LOCK_DIR/rotate.lock"
STATE_FILE="$LOCK_DIR/status"
CONF_FILE="/etc/logrotate.d/traefik-logs"

mkdir -p "$LOCK_DIR"
touch "$STATE_FILE"

exec 200>"$LOCK_FILE"
if ! flock -n 200; then
  # Another node already holds the lock this cycle -- normal, not an error.
  exit 0
fi

/usr/sbin/logrotate -s "$STATE_FILE" "$CONF_FILE"