#!/bin/bash

set -e

# 2 locks are needed. The first one ensure we don't run
# The pre-backup script twice. It's an atomic lock.
# Then we need a second lock which will last until the post-backup ran
# This one doesn't need to be atomic (as we already checked this)
PRELOCKFILE="/var/lock/pre-bkp.lock"
exec 200>$PRELOCKFILE
flock -n 200 || ( echo "Couldn't aquire pre-backup lock" && exit 1 )
PID=$$
echo $PID 1>&200

if [ -e /var/lock/bkp.lock ]; then
  # Consider the lock to be stale if it's older than 8 hours
  if [ "$(( $(date +"%s") - $(stat -c "%Y" /var/lock/bkp.lock) ))" -gt "28800" ]; then
    rm /var/lock/bkp.lock
  else
    echo "Another backup is running"
    exit 1
  fi
fi
touch /var/lock/bkp.lock
if [ -d "/etc/backup/pre.d" ]; then
  for H in $(find /etc/backup/pre.d -type f -o -type l | sort); do
    if [ -x $H ]; then
      echo "Running hook $H"
      $H "$@"
      echo "Finished hook $H"
    else
      echo "Skiping hook $H as it's not executable"
    fi
  done
fi