iankelling.org Git - distro-setup/blob - mailbindwatchdog

   1 #!/bin/bash
   2
   3 # When the system boots, systemd-resolved seems to recreate /run/systemd/resolve,
   4 # or something, because the bindmounts to that directory do not always exist
   5 # for units starting up at the same time. Anyways, removing and creating that
   6 # directory definitely has the effect of deleting the bindmount, so
   7 # here I solve for that ever happening.
   8
   9 if ! test "$BASH_VERSION"; then echo "error: shell is not bash" >&2; exit 1; fi
  10 shopt -s inherit_errexit 2>/dev/null ||: # ignore fail in bash < 4.4
  11 set -eE -o pipefail
  12 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" exit status: $?, PIPESTATUS: ${PIPESTATUS[*]}" >&2' ERR
  13
  14 if (( $# == 0 )); then
  15   echo error: expected service argument >&2
  16   exit 1
  17 fi
  18
  19 [[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"
  20
  21 sleep 5
  22 while true; do
  23   sleep 20
  24   for unit; do
  25     pid=$(systemctl show --property MainPID --value $unit 2>/dev/null ||:)
  26     case $pid in
  27       [1-9]*)
  28         if ! nsenter -t $pid -m timeout 20 mountpoint /run/systemd/resolve &>/dev/null; then
  29           echo mail bind restart of $unit
  30           timeout 60 systemctl restart $unit ||:
  31         fi
  32         ;;
  33     esac
  34   done
  35 done