iankelling.org Git - distro-setup/blob - lan-dyn-dns-update

   1 #!/bin/bash
   2
   3 # usage: I run this script on a timer to correct the dns on wrt for
   4 # clients where dns is updated dynamically by openvpn, in the case that
   5 # openvpn crashes or the computer running openvpn crashes.
   6
   7 set -eE -o pipefail
   8 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
   9
  10 x="$(readlink -f "$BASH_SOURCE")"; cd ${x%/*} # directory of this file
  11
  12 while read -r ip host; do
  13     found=false
  14     is_connected="grep -q "^CLIENT_LIST,$host," /run/openvpn-server/status-server.log"
  15     if $is_connected; then continue; fi
  16     if ! grep -q "^CLIENT_LIST,$host," /run/openvpn-server/status-server.log; then
  17         cd $(mktemp -d); dir=$PWD
  18         ssh wrt tar -C /etc -c hosts | tar -x
  19         if grep -qFx "$ip $host" hosts; then continue; fi
  20         # openvpn udpates its status file every 60 seconds by default
  21         if (( $(stat -c%Y hosts) > $(( $(date +%s) + 60 )) )); then
  22             sleep 60
  23             if $is_connected; then continue; fi
  24         fi
  25         ssh root@wrt.b8.nz cedit ovpn-$host <<<"$ip $host" || [[ $? == 1 ]]
  26     fi
  27 done <lan-dns