iankelling.org Git - distro-setup/blob - switch-mail-host

   1 #!/bin/bash
   2 set -x
   3 set -eE -o pipefail
   4 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
   5
   6 usage() {
   7   cat <<EOF
   8 Usage: ${0##*/} OLD_HOST NEW_HOST
   9
  10 Adjust home network dns so NEW_HOST resolves locally if it is on the
  11 local network.  Turn off mail receiving on OLD_HOST, run btrbk to move
  12 mail to NEW_HOST, turn on mail receiving on NEW_HOST.
  13
  14 -o         Only btrbk /o, instead of all filesystems.
  15 -w         Don't try to ssh to wrt. Should only be used in unusual network situation.
  16 -h|--help  Print help and exit.
  17
  18 Note: Uses GNU getopt options parsing style
  19 EOF
  20   exit $1
  21 }
  22
  23 ##### begin command line parsing ########
  24
  25 update_wrt=true # default
  26 temp=$(getopt -l help owh "$@") || usage 1
  27 mp_args=
  28 eval set -- "$temp"
  29 while true; do
  30   case $1 in
  31     -o) mp_args="-m /o"; shift ;;
  32     -w) update_wrt=false; shift ;;
  33     -h|--help) usage ;;
  34     --) shift; break ;;
  35     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  36   esac
  37 done
  38
  39
  40 (( $# == 2 )) || usage 1
  41
  42 old_host=$1
  43 new_host=$2
  44 source /a/bin/bash_unpublished/source-semi-priv
  45
  46 if [[ $old_host != $MAIL_HOST ]]; then
  47   read -p "warning: \$old_host != \$MAIL_HOST: $old_host != $MAIL_HOST, proceed? y/N "
  48   if [[ $REPLY != [yY] ]]; then
  49     exit 1
  50   fi
  51 fi
  52
  53 if [[ $new_host == "$HOSTNAME" ]]; then
  54   localhost_new=true
  55   new_shell=
  56 else
  57   localhost_new=false
  58   new_shell="ssh $new_host"
  59 fi
  60
  61 old_shell="ssh $old_host"
  62 if [[ $old_host == "$HOSTNAME" ]]; then
  63   old_shell=
  64 fi
  65
  66 if [[ ! $new_host || ! $old_host ]]; then
  67   echo "$0: bad args. see script"
  68   exit 1
  69 fi
  70
  71 at_home=false
  72 if timeout -s 9 5 ssh-keyscan -p 2220 -t rsa 10.0.0.1 2>/dev/null | grep -qFx '[10.0.0.1]:2220 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCH+/h1dGEfKEusBblndU2e6QT4wLCm5+yqr/sqh/0X9YfjR7BfWWm8nNmuP55cYc+Wuf5ljB1H1acXEcsl1y8e0j3agHfF0V74FE1N1zz5nn2Ep8NHnmqgEhza38ZxMPh+4p3X7zklEKU7+3SzybKBi8sg0wLzlS2LM0JaUN80zR2sK11Kye3dURUXPk78u5wodOkgcEYRwSYaDMJlUzWP+poRXIDJwFaMQnwmxbl/c84yOyaU0x/d6hFwoRscWecihX+vvBNeSyxR4xr2HDOyUWwJkctyAgt2p7w3tfkXOKcCRzTAjGVIMQLTvo0sG/yJbcyHoEFdFybCsgDvfyYn'; then
  73   at_home=true
  74 fi
  75 echo "$0: at_home = $at_home"
  76
  77 source /a/bin/bash_unpublished/source-semi-priv
  78 #### begin convert private hostnames to public hostnames ####
  79 #if ! $at_home; then
  80 #    for var in old_host new_host; do
  81 #        case ${!var} in
  82 #            tp)
  83 #                eval $var=$HOME_DOMAIN
  84 #                ;;
  85 #        esac
  86 #    done
  87 #fi
  88 ####  end convert private hostnames to public hostnames ####
  89
  90
  91 # because our port forward is not robust enough, we can't use proxy command,
  92 # todo: setup vpn so this is all taken care of.
  93 if ! $update_wrt; then
  94   wrt_shell=:
  95 else
  96   wrt_shell="ssh wrt.b8.nz"
  97 fi
  98
  99 btrbk_test="systemctl is-active btrbk.service"
 100 while $new_shell $btrbk_test || $old_shell $btrbk_test; do
 101   echo "$0: btrbk is running on new or old host. sleeping for 8 seconds"
 102   sleep 6
 103   echo "$0: testing for btrbk activity in 2 seconds"
 104   sleep 2
 105 done
 106
 107 new_hostname=$($new_shell hostname)
 108
 109 ########### end initial processing, begin actually modifying things ##########
 110
 111 restore_new_btrbk=false
 112 if $new_shell systemctl is-active btrbk.timer; then
 113   $new_shell sudo systemctl stop btrbk.timer
 114   restore_new_btrbk=true
 115 fi
 116 restore_old_btrbk=false
 117 if $old_shell systemctl is-active btrbk.timer; then
 118   $old_shell sudo systemctl stop btrbk.timer
 119   restore_old_btrbk=true
 120 fi
 121
 122
 123 $new_shell bash -xs <<'EOF'
 124 set -eE
 125 if mountpoint -q /m; then sudo umount /m; fi
 126 if mountpoint -q /o; then sudo umount /o; fi
 127 EOF
 128
 129 # previously, I was checking to see if the new mail host
 130 # is on my home network, then changing my home dns
 131 # to resolve on the local network, so that I didnt
 132 # have to send traffic out to the internet or rely
 133 # on that. However, that breaks for a laptop that roams.
 134 # So, we could have a cronjob that updates that dns,
 135 # however, another solution is to just use ipv6,
 136 # and I prefer that.
 137 #
 138 # TODO: enable ipv6 for email. exim config setting disables it.
 139 # need to add vpn support. need to add firewall / routing.
 140 # I think exim will try ipv6 first, so no need to disable
 141 # ipv6 i think.
 142
 143 $old_shell primary-setup $new_hostname
 144
 145 if $localhost_new; then
 146   btrbk-run -s $old_host $mp_args
 147 else
 148   btrbk-run -t $new_host $mp_args
 149 fi
 150
 151 $new_shell primary-setup $new_hostname
 152
 153 if $restore_new_btrbk; then
 154   $new_shell sudo systemctl start btrbk.timer
 155 fi
 156 if $restore_old_btrbk; then
 157   $old_shell sudo systemctl start btrbk.timer
 158 fi