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: switch-mail-host|switch-host2 [OPTIONS] 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 -a         Avoid snapshot /a, /q, and similar. If we haven't
  14            made any changes in the last hour, there is no
  15            need to snapshot anything but /o, and we will
  16            just do that once.
  17 -i         Disallow incremental backup.
  18 -o         Only btrbk /o, instead of all filesystems.
  19 --force    Run even though our local state does not say that MAIL_HOST is
  20            us when pushing or HOST when pulling.
  21 -h|--help  Print help and exit.
  22
  23 I used to adjust home network dns so NEW_HOST resolves locally if it is
  24 on the local network, but its simpler just not to and just rely
  25 on the internet. Email can wait.
  26
  27 Note: Uses GNU getopt options parsing style
  28 EOF
  29   exit 0
  30 }
  31
  32 script_name="${BASH_SOURCE[0]}"
  33 script_name="${script_name##*/}"
  34
  35 restore_new_btrbk=false
  36 restore_old_btrbk=false
  37 err-cleanup() {
  38   if $restore_new_btrbk; then
  39     e WARNING: due to failure, btrbk.timer may need manual restoration:
  40     e $new_shell systemctl start btrbk.timer
  41   fi
  42   if $restore_old_btrbk; then
  43     e WARNING: due to failure, btrbk.timer may need manual restoration:
  44     e $old_shell systemctl start btrbk.timer
  45   fi
  46 }
  47
  48 pre="$script_name:"
  49 m() { printf "$pre %s\n"  "$*"; "$@"; }
  50 e() { printf "$pre %s\n"  "$*"; }
  51 err() { echo "$pre ERROR: $*" >&2; }
  52 die() { printf "%s\n" "$*" >&2; echo "exiting with status 1" >&2; exit 1; }
  53
  54 if [[ $EUID != 0 ]]; then
  55   err "requires running as root"
  56   exit 1
  57 fi
  58
  59
  60 ##### begin command line parsing ########
  61
  62 mail_only=false
  63 host2_only=false
  64 force=false
  65 force_arg=
  66 pull_reexec=false
  67 mp_args="-m /o,/a,/ar,/q,/qd,/qr"
  68 check_installed=false
  69 orig_args=("$@")
  70 if ! temp=$(getopt -l check-installed,force,pull-reexec,help afioh "$@"); then
  71   err "args invalid. args=$*"
  72 fi
  73 eval set -- "$temp"
  74 while true; do
  75   case $1 in
  76     -a) snapshot_arg=resume ;;
  77     --force|-f)
  78       force=true
  79       force_arg=-f
  80       ;;
  81     --check-installed)
  82       check_installed=true
  83       ;;
  84     -i) incremental_arg="-i" ;;
  85     # internal option for rerunning under newer old_host when doing pull
  86     --pull-reexec) pull_reexec=true;;
  87     -o)
  88       mail_only=true ;;
  89     -h|--help) usage ;;
  90     --) shift; break ;;
  91     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  92   esac
  93   shift
  94 done
  95
  96
  97 if (( $# != 2 )) && ! $check_installed; then
  98   err expected 2 args, got $#
  99 fi
 100
 101 if [[ ! $HOSTNAME ]]; then
 102   err "\$HOSTNAME is unset"
 103   exit 1
 104 fi
 105
 106 uninstalled-file-die() {
 107   die "on host=$HOSTNAME, uninstalled file $1. run install-my-scripts or rerun with -f"
 108 }
 109
 110
 111 source /a/bin/bash_unpublished/source-state
 112
 113 direction=$1
 114 host=$2
 115
 116
 117 if ! $force && { $check_installed || [[ $direction == push ]]; } ; then
 118   install_bin_files=(
 119     mount-latest-subvol
 120     check-subvol-stale
 121     btrbk-run
 122     switch-mail-host
 123   )
 124   for f in ${install_bin_files[@]}; do
 125     if ! diff -q /a/bin/ds/$f /usr/local/bin/$f; then
 126       uninstalled-file-die $f
 127     fi
 128   done
 129   if ! diff -q /a/bin/errhandle/err /usr/local/lib/err; then
 130     uninstalled-file-die err
 131   fi
 132   if $check_installed; then
 133     exit 0
 134   fi
 135 fi
 136
 137
 138 case $direction in
 139   push)
 140     old_host=$HOSTNAME
 141     old_hostname=$HOSTNAME
 142     new_host=$host
 143     bbk_args="-t $new_host"
 144     new_shell="ssh -F $HOME/.ssh/confighome root@$new_host"
 145     if ! new_hostname=$($new_shell hostname); then
 146       echo "$pre: error: failed ssh. retrying failed $new_shell with -v for more info:"
 147       $new_shell -v hostname
 148     fi
 149     ;;
 150   pull)
 151     old_host=$host
 152     new_host=$HOSTNAME
 153     new_hostname=$HOSTNAME
 154     bbk_args="-s $old_host"
 155     old_shell="ssh -F $HOME/.ssh/confighome root@$old_host"
 156     # tests ssh connection. crafted this to not need to do escape chars
 157
 158     if ! $mail_only && ! $pull_reexec ; then
 159       if ! $force; then
 160         if ! $old_shell switch-mail-host --check-installed; then
 161           die "failed: $old_shell switch-mail-host --check-installed"
 162         fi
 163       fi
 164       tmpf=$(mktemp)
 165       m scp -F $HOME/.ssh/confighome root@$old_host:/usr/local/bin/switch-mail-host $tmpf
 166       if ! diff -q $tmpf ${BASH_SOURCE[0]}; then
 167         e "found different version on old_host=$old_hostname, reexecing"
 168         m install -T $tmpf /usr/local/bin/switch-mail-host
 169         m /usr/local/bin/switch-mail-host --pull-reexec "${orig_args[@]}"
 170         exit 0
 171       fi
 172     fi
 173
 174     f=/a/bin/bash_unpublished/source-state
 175     if ! old_info=$($old_shell "hostname; sed -n s,.*MAIL_HOST=,,p $f; sed -n s,.*HOST2=,,p $f"); then
 176       echo "$pre: error: failed ssh. retrying failed $old_shell with -v for more info:"
 177       $old_shell -v hostname
 178       exit 1
 179     fi
 180     read -d '' -r old_hostname MAIL_HOST HOST2 <<<"$old_info" || (( $? == 1 ))
 181
 182     ;;
 183   *)
 184     err invalid first argument
 185     exit 1
 186     ;;
 187 esac
 188
 189 case $script_name in
 190   switch-mail-host)
 191     if [[ $MAIL_HOST != "$HOST2" ]]; then
 192       mail_only=true
 193     fi
 194     ;;
 195   switch-host2)
 196     host2_only=true
 197     ;;
 198   *)
 199     err unexpected script name
 200     ;;
 201 esac
 202
 203 if $mail_only; then
 204   mp_args="-m /o"
 205 elif $host2_only; then
 206   mp_args="-m /a,/ar,/q,/qd,/qr"
 207 fi
 208
 209 if ! $force; then
 210   if $host2_only; then
 211     if [[ $old_hostname != "$HOST2" ]]; then
 212       err "\$old_hostname($old_hostname) != \$HOST2($HOST2). Rerun with --force if you really want this."
 213       exit 1
 214     fi
 215   elif [[ $old_hostname != "$MAIL_HOST" ]]; then
 216     err "\$old_hostname($old_hostname) != \$MAIL_HOST($MAIL_HOST). Rerun with --force if you really want this."
 217     exit 1
 218   fi
 219 fi
 220
 221 if [[ ! $new_host || ! $old_host ]]; then
 222   echo "$0: bad args. see script"
 223   exit 1
 224 fi
 225
 226
 227 ########### end initial processing, begin actually modifying things ##########
 228
 229 if $new_shell systemctl is-active btrbk.timer; then
 230   m $new_shell systemctl stop btrbk.timer
 231   restore_new_btrbk=true
 232 fi
 233 if $old_shell systemctl is-active btrbk.timer; then
 234   m $old_shell systemctl stop btrbk.timer
 235   restore_old_btrbk=true
 236 fi
 237
 238 btrbk_test="systemctl is-active btrbk.service"
 239 active=true
 240 while $active; do
 241   active=false
 242   for shell in "$new_shell" "$old_shell"; do
 243     e $shell $btrbk_test
 244     status=$($shell $btrbk_test) ||:
 245     case $status in
 246       inactive|failed) : ;;
 247       *)
 248         # This covers conditions like "activating", which still return 3 from
 249         # systemctl is-active.
 250         active=true
 251         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 252         sleep 8
 253         break
 254         ;;
 255     esac
 256   done
 257 done
 258
 259 # ensure these are unused before doing anything
 260 e "On $new_host: umounting /m and /o, checking emacs"
 261 {
 262   cat <<'EOF'
 263 set -eE
 264 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 265   bufs="$(sudo -u iank env XDG_RUNTIME_DIR=/run/user/1000 emacsclient --eval "$(cat /a/bin/ds/unsaved-buffers.el)"| sed '/^"nil"$/d;s/^"(/E: /;s/)"$//')"
 266   if [[ $bufs ]]; then
 267     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 268     exit 1
 269   fi
 270 fi
 271 EOF
 272   if ! $host2_only; then
 273     cat <<EOF
 274 for dir in m o; do
 275   if mountpoint -q /\$dir; then
 276     echo On $new_host: umount /\$dir
 277     umount /\$dir
 278   fi
 279 done
 280 EOF
 281   fi
 282 } | $new_shell bash -s
 283
 284 if ! $mail_only; then
 285   $old_shell bash -s <<'EOF'
 286 set -e
 287 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 288   bufs="$(sudo -u iank env XDG_RUNTIME_DIR=/run/user/1000 emacsclient --eval "$(cat /a/bin/ds/unsaved-buffers.el)"| sed '/^"nil"$/d;s/^"(/E: /;s/)"$//')"
 289   if [[ $bufs ]]; then
 290     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 291     exit 1
 292   fi
 293 fi
 294
 295 # Try to prevent emacs from saving stale data it has in memory to disk. eg: files, recentf list, etc.
 296 # But if emacs ignores the signal, let it live.
 297 killall -q emacs ||:
 298
 299 if [[ -e /p/profanity-here ]]; then
 300   systemctl disable --now profanity
 301 fi
 302 EOF
 303 fi
 304
 305 # previously, I was checking to see if the new mail host
 306 # is on my home network, then changing my home dns
 307 # to resolve on the local network, so that I didnt
 308 # have to send traffic out to the internet or rely
 309 # on that. However, that breaks for a laptop that roams.
 310 # So, we could have a cronjob that updates that dns,
 311 # however, another solution is to just use ipv6,
 312 # and I prefer that.
 313 #
 314 # TODO: enable ipv6 for email. exim config setting disables it.
 315 # need to add vpn support. need to add firewall / routing.
 316 # I think exim will try ipv6 first, so no need to disable
 317 # ipv6 i think.
 318
 319
 320 e Running initial btrbk
 321 m btrbk-run -v $bbk_args $force_arg $incremental_arg $mp_args $snapshot_arg || ret=$?
 322 if (( ret )); then
 323   err "failed initial btrbk"
 324   exit $ret
 325 fi
 326
 327 if ! $mail_only; then
 328   m $old_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 329   m $new_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 330 fi
 331
 332 if $host2_only; then
 333   if [[ $old_hostname != "$MAIL_HOST" && $old_hostname != kd ]]; then
 334     m $old_shell systemctl --now disable btrbk.timer
 335   fi
 336   m $new_shell systemctl --now enable btrbk.timer
 337   if [[ -e /p/profanity-here ]]; then
 338     m $new_shell systemctl --now enable profanity
 339   fi
 340   exit 0
 341 fi
 342
 343 m $old_shell /a/exe/primary-setup $new_hostname || ret=$?
 344 if (( ret )); then
 345   err "failed \$old_shell primary-setup \$new_hostname. fix and rerun $script_name"
 346   exit $ret
 347 fi
 348
 349
 350 e Running main btrbk
 351 m btrbk-run -v --fast $bbk_args $force_arg $incremental_arg -m /o || ret=$?
 352 if (( ret )); then
 353   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 354   e $bang failed btrbk of /o. restoring old host as primary
 355   m $old_shell /a/exe/primary-setup localhost
 356   exit $ret
 357 fi
 358
 359 # new system is usable at this point
 360 blocks=██████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████
 361 printf "%s\n" "$(tput setaf 5 2>/dev/null ||:)${blocks:0:${COLUMNS:-180}}$(tput sgr0 2>/dev/null||:)"
 362
 363 # once I accidentally accepted incoming mail on old host. I used this script to copy over that mail:
 364 #
 365 # die=false; for d in o.leaf.2021-05-29T10:02:08-0400/m/{4e,md,4e2}/{,l/}!(*myarchive)/new; do if $die; then break; fi; find $d -type f -mtime -5 | while read -r f; do dir="${f%new/*}"; dir="btrbk/o.20210530T000011-0400/${dir#*/}"; fname="${f##*/}"; [[ -e $dir/new/$fname || -e $dir/cur/$fname ]] && continue; if ! e cp -a $f /${dir#*/*/}new; then echo failed cp; die=true; break; fi ; done; done
 366
 367 # once I accidentally sent mail from non-main mail host. to copy into the main mail host's sent dir, cd into dir of non-mail mail host Sent/cur, then
 368 #
 369 # shopt -s nullglob; find . -type f -mtime -2 | while read -r f; do a=( /m/4e/Sent/cur/${f%,*}* ); if (( ${#a[@]} )); then e exists $a; else m cp -a $f /m/4e/Sent/cur; fi; done
 370
 371 m $new_shell /a/exe/primary-setup localhost || ret=$?
 372 if (( ret )); then
 373   err "failed final primary-setup, just fix and rerun: $new_shell /a/exe/primary-setup localhost"
 374   exit $ret
 375 fi
 376
 377 if ! $mail_only && [[ -e /p/profanity-here ]]; then
 378   m $new_shell systemctl --now enable profanity || ret=$?
 379   if (( ret )); then
 380     err "failed final systemctl --now enable profanity, just fix and rerun"
 381     exit $ret
 382   fi
 383 fi
 384
 385 m exit 0