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 -w         Don't try to ssh to wrt. Should only be used in unusual network situation.
  15 -h|--help  Print help and exit.
  16
  17 Note: Uses GNU getopt options parsing style
  18 EOF
  19   exit $1
  20 }
  21
  22 ##### begin command line parsing ########
  23
  24 update_wrt=true # default
  25 temp=$(getopt -l help wh "$@") || usage 1
  26 eval set -- "$temp"
  27 while true; do
  28   case $1 in
  29     -w) update_wrt=false; shift ;;
  30     -h|--help) usage ;;
  31     --) shift; break ;;
  32     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  33   esac
  34 done
  35
  36
  37 (( $# == 2 )) || usage 1
  38
  39 old_host=$1
  40 new_host=$2
  41 source /a/bin/bash_unpublished/source-semi-priv
  42
  43 if [[ $old_host != $MAIL_HOST ]]; then
  44   read -p "warning: \$old_host != \$MAIL_HOST: $old_host != $MAIL_HOST, proceed? y/N "
  45   if [[ $REPLY != [yY] ]]; then
  46     exit 1
  47   fi
  48 fi
  49
  50 if [[ $new_host == "$HOSTNAME" ]]; then
  51   localhost_new=true
  52   new_shell=
  53 else
  54   localhost_new=false
  55   new_shell="ssh $new_host"
  56 fi
  57
  58 old_shell="ssh $old_host"
  59 if [[ $old_host == "$HOSTNAME" ]]; then
  60   old_shell=
  61 fi
  62
  63 if [[ ! $new_host || ! $old_host ]]; then
  64   echo "$0: bad args. see script"
  65   exit 1
  66 fi
  67
  68 # TODO: make home dns use ipv6. for work, make a cronjob that updates
  69 # the dns there.
  70 #
  71 # This exists because if mail_host is on the home network with a vpn
  72 # tunnel, and another host on the home network tries to connect to the
  73 # public tunnel ip, it won't work because from the public machine's
  74 # perspective, due to nat, both home network machines have the same
  75 # ip. We could solve this by using ipv6 addresses, but not all networks
  76 # i'm on with more than one machine are ipv6 enabled.
  77 at_home=false
  78 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
  79   at_home=true
  80 fi
  81 echo "$0: at_home = $at_home"
  82
  83 source /a/bin/bash_unpublished/source-semi-priv
  84 #### begin convert private hostnames to public hostnames ####
  85 #if ! $at_home; then
  86 #    for var in old_host new_host; do
  87 #        case ${!var} in
  88 #            tp)
  89 #                eval $var=$HOME_DOMAIN
  90 #                ;;
  91 #        esac
  92 #    done
  93 #fi
  94 ####  end convert private hostnames to public hostnames ####
  95
  96
  97 # because our port forward is not robust enough, we can't use proxy command,
  98 # todo: setup vpn so this is all taken care of.
  99 if ! $update_wrt; then
 100   wrt_shell=:
 101 else
 102   wrt_shell="ssh wrt.b8.nz"
 103 fi
 104
 105 btrbk_test="systemctl is-active btrbk.service"
 106 while $new_shell $btrbk_test || $old_shell $btrbk_test; do
 107   echo "$0: btrbk is running on new or old host. sleeping for 8 seconds"
 108   sleep 6
 109   echo "$0: testing for btrbk activity in 2 seconds"
 110   sleep 2
 111 done
 112
 113 new_hostname=$($new_shell hostname)
 114
 115 ########### end initial processing, begin actually modifying things ##########
 116
 117 restore_new_btrbk=false
 118 if $new_shell systemctl is-active btrbk.timer; then
 119   $new_shell sudo systemctl stop btrbk.timer
 120   restore_new_btrbk=true
 121 fi
 122 restore_old_btrbk=false
 123 if $old_shell systemctl is-active btrbk.timer; then
 124   $old_shell sudo systemctl stop btrbk.timer
 125   restore_old_btrbk=true
 126 fi
 127
 128
 129 $new_shell bash -xs <<'EOF'
 130 set -eE
 131 if mountpoint -q /m; then sudo umount /m; fi
 132 if mountpoint -q /o; then sudo umount /o; fi
 133 EOF
 134
 135 # if new_host is not on home network, make mail.iankelling.org not resolve
 136 # on the home network.
 137 if [[ $new_host == $HOSTNAME ]] && ! $at_home; then
 138   echo | $wrt_shell cedit mail_host /etc/hosts || [[ $? == 1 ]] # 1 means file changed.
 139 else
 140   $wrt_shell bash -xs $new_host <<'EOFOUTER'
 141 new_host=$1
 142 cedit mail_host /etc/hosts <<EOF || /etc/init.d/dnsmasq restart
 143 $(grep "\b$new_hostname\b" /etc/hosts | awk '{print $1}') mail.iankelling.org
 144 EOF
 145 EOFOUTER
 146 fi
 147
 148 $old_shell primary-setup $new_hostname
 149
 150 /a/bin/distro-setup/install-my-scripts
 151
 152 if $localhost_new; then
 153   btrbk-run -s $old_host -m /o
 154 else
 155   btrbk-run -t $new_host -m /o
 156 fi
 157
 158 $new_shell primary-setup $new_hostname
 159
 160 if $restore_new_btrbk; then
 161   $new_shell sudo systemctl start btrbk.timer
 162 fi
 163 if $restore_old_btrbk; then
 164   $old_shell sudo systemctl start btrbk.timer
 165 fi