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

   1 #!/bin/bash
   2
   3 source /usr/local/lib/err
   4
   5 usage() {
   6   cat <<EOF
   7 Usage: ${0##*/} push|pull HOST
   8
   9 Turn off mail receiving on OLD_HOST, run btrbk to move mail to NEW_HOST,
  10 turn on mail receiving on NEW_HOST.  Assumes we want to move all
  11 filesystems unless passing -o.
  12
  13 -o         Only btrbk /o, instead of all filesystems.
  14 -h|--help  Print help and exit.
  15
  16 I used to adjust home network dns so NEW_HOST resolves locally if it is
  17 on the local network, but its simpler just not to and just rely
  18 on the internet. Email can wait.
  19
  20 Note: Uses GNU getopt options parsing style
  21 EOF
  22   exit $1
  23 }
  24
  25 restore_new_btrbk=false
  26 restore_old_btrbk=false
  27 cleanup() {
  28   if $restore_new_btrbk; then
  29     e WARNING: due to failure, btrbk.timer may need manual restoration:
  30     e $new_shell sudo systemctl start btrbk.timer
  31   fi
  32   if $restore_old_btrbk; then
  33     e WARNING: due to failure, btrbk.timer may need manual restoration:
  34     e $old_shell sudo systemctl start btrbk.timer
  35   fi
  36 }
  37 b
  38 pre="${0##*/}:"
  39 m() { printf "$pre %s\n"  "$*"; "$@"; }
  40 e() { printf "$pre %s\n"  "$*"; }
  41 err() { echo "[$(date +'%Y-%m-%d %H:%M:%S%z')]: $pre: $*" >&2; }
  42
  43 ##### begin command line parsing ########
  44
  45 temp=$(getopt -l help owh "$@") || usage 1
  46 mp_args="-m /o,/q,/a"
  47 eval set -- "$temp"
  48 while true; do
  49   case $1 in
  50     -o) mp_args="-m /o"; shift ;;
  51     -h|--help) usage ;;
  52     --) shift; break ;;
  53     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  54   esac
  55 done
  56
  57
  58 (( $# == 2 )) || usage 1
  59
  60
  61 case $1 in
  62   push)
  63     new_host=$2
  64     bbk_args="-s $old_host"
  65     new_shell="ssh $new_host"
  66     old_host=$HOSTNAME
  67     ;;
  68   pull)
  69     old_host=$2
  70     bbk_args="-t $new_host"
  71     bbk_args="-s $old_host"
  72     new_host=$HOSTNAME
  73     old_shell="ssh $old_host"
  74     ;;
  75   *)
  76     err invalid first argument
  77     exit 1
  78     ;;
  79 esac
  80
  81
  82 source /a/bin/bash_unpublished/source-state
  83
  84 if [[ $old_host != "$MAIL_HOST" ]]; then
  85   read -r -p "warning: \$old_host != \$MAIL_HOST: $old_host != $MAIL_HOST, proceed? y/N "
  86   if [[ $REPLY != [yY] ]]; then
  87     exit 1
  88   fi
  89 fi
  90
  91 if [[ ! $new_host || ! $old_host ]]; then
  92   echo "$0: bad args. see script"
  93   exit 1
  94 fi
  95
  96 e $new_shell hostname
  97 new_hostname=$($new_shell hostname)
  98
  99 ########### end initial processing, begin actually modifying things ##########
 100
 101 if $new_shell systemctl is-active btrbk.timer; then
 102   m $new_shell sudo systemctl stop btrbk.timer
 103   _errcatch_cleanup=cleanup
 104   restore_new_btrbk=true
 105 fi
 106 if $old_shell systemctl is-active btrbk.timer; then
 107   m $old_shell sudo systemctl stop btrbk.timer
 108   _errcatch_cleanup=cleanup
 109   restore_old_btrbk=true
 110 fi
 111
 112 btrbk_test="systemctl is-active btrbk.service"
 113 while true; do
 114   for shell in "$new_shell" "$old_shell"; do
 115     e $shell $btrbk_test
 116     status=$($shell $btrbk_test) ||:
 117     case $status in
 118       inactive|failed) : ;;
 119       *)
 120         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 121         sleep 8
 122         continue
 123         ;;
 124     esac
 125   done
 126   break
 127 done
 128
 129 # ensure these are unused before doing anything
 130
 131 e "umounting /m and /o via $new_shell"
 132 $new_shell bash -xs <<'EOF'
 133 set -eE
 134 if mountpoint -q /m; then sudo umount /m; fi
 135 if mountpoint -q /o; then sudo umount /o; fi
 136 EOF
 137
 138 # previously, I was checking to see if the new mail host
 139 # is on my home network, then changing my home dns
 140 # to resolve on the local network, so that I didnt
 141 # have to send traffic out to the internet or rely
 142 # on that. However, that breaks for a laptop that roams.
 143 # So, we could have a cronjob that updates that dns,
 144 # however, another solution is to just use ipv6,
 145 # and I prefer that.
 146 #
 147 # TODO: enable ipv6 for email. exim config setting disables it.
 148 # need to add vpn support. need to add firewall / routing.
 149 # I think exim will try ipv6 first, so no need to disable
 150 # ipv6 i think.
 151
 152
 153
 154 m $old_shell /a/exe/primary-setup $new_hostname
 155
 156 if ! m btrbk-run -v $bbk_args $mp_args; then
 157   ret=$?
 158   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 159   e $bang failed btrbk. restoring old host as primary
 160   m $old_shell /a/exe/primary-setup localhost
 161   exit $ret
 162 fi
 163
 164 m $new_shell /a/exe/primary-setup localhost