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 errcatch-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 $old_shell sudo systemctl start btrbk.timer
  35   fi
  36 }
  37
  38 pre="${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 mexit() { echo "exiting with status $1"; exit $1; }
  43
  44 ##### begin command line parsing ########
  45
  46 temp=$(getopt -l help owh "$@") || usage 1
  47 mp_args="-m /o,/q,/a"
  48 eval set -- "$temp"
  49 while true; do
  50   case $1 in
  51     -o) mp_args="-m /o"; shift ;;
  52     -h|--help) usage ;;
  53     --) shift; break ;;
  54     *) echo "$0: Internal error! unexpected args: $*" ; mexit 1 ;;
  55   esac
  56 done
  57
  58
  59 (( $# == 2 )) || usage 1
  60
  61
  62 case $1 in
  63   push)
  64     new_host=$2
  65     bbk_args="-s $old_host"
  66     new_shell="ssh $new_host"
  67     old_host=$HOSTNAME
  68     ;;
  69   pull)
  70     old_host=$2
  71     bbk_args="-t $new_host"
  72     bbk_args="-s $old_host"
  73     new_host=$HOSTNAME
  74     old_shell="ssh $old_host"
  75     ;;
  76   *)
  77     err invalid first argument
  78     mexit 1
  79     ;;
  80 esac
  81
  82
  83 source /a/bin/bash_unpublished/source-state
  84
  85 if [[ $old_host != "$MAIL_HOST" ]]; then
  86   e "WARNING: \$old_host != \$MAIL_HOST. Sleeping for 5 seconds in case you want to reconsider"
  87   sleep 5
  88 fi
  89
  90 if [[ ! $new_host || ! $old_host ]]; then
  91   echo "$0: bad args. see script"
  92   mexit 1
  93 fi
  94
  95 e $new_shell hostname
  96 new_hostname=$($new_shell hostname)
  97
  98 ########### end initial processing, begin actually modifying things ##########
  99
 100 if $new_shell systemctl is-active btrbk.timer; then
 101   m $new_shell sudo systemctl stop btrbk.timer
 102   restore_new_btrbk=true
 103 fi
 104 if $old_shell systemctl is-active btrbk.timer; then
 105   m $old_shell sudo systemctl stop btrbk.timer
 106   restore_old_btrbk=true
 107 fi
 108
 109 btrbk_test="systemctl is-active btrbk.service"
 110 while true; do
 111   for shell in "$new_shell" "$old_shell"; do
 112     e $shell $btrbk_test
 113     status=$($shell $btrbk_test) ||:
 114     case $status in
 115       inactive|failed) : ;;
 116       *)
 117         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 118         sleep 8
 119         continue
 120         ;;
 121     esac
 122   done
 123   break
 124 done
 125
 126 # ensure these are unused before doing anything
 127
 128 e "umounting /m and /o via $new_shell"
 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 # previously, I was checking to see if the new mail host
 136 # is on my home network, then changing my home dns
 137 # to resolve on the local network, so that I didnt
 138 # have to send traffic out to the internet or rely
 139 # on that. However, that breaks for a laptop that roams.
 140 # So, we could have a cronjob that updates that dns,
 141 # however, another solution is to just use ipv6,
 142 # and I prefer that.
 143 #
 144 # TODO: enable ipv6 for email. exim config setting disables it.
 145 # need to add vpn support. need to add firewall / routing.
 146 # I think exim will try ipv6 first, so no need to disable
 147 # ipv6 i think.
 148
 149
 150 e Running initial btrbk
 151 if ! m btrbk-run -v $bbk_args $mp_args; then
 152   ret=$?
 153   err "failed initial btrbk"
 154   mexit $ret
 155 fi
 156
 157 m $old_shell /a/exe/primary-setup $new_hostname
 158
 159 e Running main btrbk
 160 if ! m btrbk-run -v $bbk_args -m /o; then
 161   ret=$?
 162   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 163   e $bang failed btrbk of /o. restoring old host as primary
 164   m $old_shell /a/exe/primary-setup localhost
 165   mexit $ret
 166 fi
 167
 168 m $new_shell /a/exe/primary-setup localhost
 169
 170 mexit 0