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

   1 #!/bin/bash
   2
   3 set -e; . /usr/local/lib/bash-bear; set +e
   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/bash-bear-trap/bash-bear /usr/local/lib/bash-bear; 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: $old_shell switch-mail-host --check-installed"
 162         fi
 163       fi
 164       tmpd=$(mktemp -d)
 165       files=(
 166         /usr/local/{bin/{unsaved-buffers{,.el},switch-mail-host},lib/bash-bear}
 167       )
 168       m scp -F $HOME/.ssh/confighome \
 169         ${files@/#/root@$old_host:} $tmpd
 170       diff=false
 171       for f in ${files[@]}; do
 172         if ! diff -q $tmpd/${f##*/} $f; then
 173           m install -T $tmpd/${f##*/} $f
 174           diff=true
 175         fi
 176       done
 177       if $diff; then
 178         e "found different version on old_host=$old_hostname, reexecing"
 179         m /usr/local/bin/switch-mail-host --pull-reexec "${orig_args[@]}"
 180         exit 0
 181       fi
 182       rm -r -- $tmpd
 183     fi
 184
 185     f=/a/bin/bash_unpublished/source-state
 186     if ! old_info=$($old_shell "hostname; sed -n s,.*MAIL_HOST=,,p $f; sed -n s,.*HOST2=,,p $f"); then
 187       echo "$pre: error: failed ssh. retrying failed $old_shell with -v for more info:"
 188       $old_shell -v hostname
 189       exit 1
 190     fi
 191     read -d '' -r old_hostname MAIL_HOST HOST2 <<<"$old_info" || (( $? == 1 ))
 192
 193     ;;
 194   *)
 195     err invalid first argument
 196     exit 1
 197     ;;
 198 esac
 199
 200 case $script_name in
 201   switch-mail-host)
 202     if [[ $MAIL_HOST != "$HOST2" ]]; then
 203       mail_only=true
 204     fi
 205     ;;
 206   switch-host2)
 207     host2_only=true
 208     ;;
 209   *)
 210     err unexpected script name
 211     ;;
 212 esac
 213
 214 if $mail_only; then
 215   mp_args="-m /o"
 216 elif $host2_only; then
 217   mp_args="-m /a,/ar,/q,/qd,/qr"
 218 fi
 219
 220 if ! $force; then
 221   if $host2_only; then
 222     if [[ $old_hostname != "$HOST2" ]]; then
 223       err "\$old_hostname($old_hostname) != \$HOST2($HOST2). Rerun with --force if you really want this."
 224       exit 1
 225     fi
 226   elif [[ $old_hostname != "$MAIL_HOST" ]]; then
 227     err "\$old_hostname($old_hostname) != \$MAIL_HOST($MAIL_HOST). Rerun with --force if you really want this."
 228     exit 1
 229   fi
 230 fi
 231
 232 if [[ ! $new_host || ! $old_host ]]; then
 233   echo "$0: bad args. see script"
 234   exit 1
 235 fi
 236
 237
 238 ########### end initial processing, begin actually modifying things ##########
 239
 240 if $new_shell systemctl is-active btrbk.timer; then
 241   m $new_shell systemctl stop btrbk.timer
 242   restore_new_btrbk=true
 243 fi
 244 if $old_shell systemctl is-active btrbk.timer; then
 245   m $old_shell systemctl stop btrbk.timer
 246   restore_old_btrbk=true
 247 fi
 248
 249 btrbk_test="systemctl is-active btrbk.service"
 250 active=true
 251 while $active; do
 252   active=false
 253   for shell in "$new_shell" "$old_shell"; do
 254     e $shell $btrbk_test
 255     status=$($shell $btrbk_test) ||:
 256     case $status in
 257       inactive|failed) : ;;
 258       *)
 259         # This covers conditions like "activating", which still return 3 from
 260         # systemctl is-active.
 261         active=true
 262         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 263         sleep 8
 264         break
 265         ;;
 266     esac
 267   done
 268 done
 269
 270 # ensure these are unused before doing anything
 271 e "On $new_host: umounting /m and /o, checking emacs"
 272 {
 273   cat /usr/local/bin/unsaved-buffers
 274   if ! $host2_only; then
 275     cat <<EOF
 276 for dir in m o; do
 277   if mountpoint -q /\$dir; then
 278     echo On $new_host: umount /\$dir
 279     umount /\$dir
 280   fi
 281 done
 282 EOF
 283   fi
 284 } | $new_shell bash -s
 285
 286 if ! $mail_only; then
 287   cat /usr/local/bin/unsaved-buffers - <<'EOF' |  $old_shell bash -s
 288
 289 # Try to prevent emacs from saving stale data it has in memory to disk. eg: files, recentf list, etc.
 290 # But if emacs ignores the signal, let it live.
 291 pkill -xf 'emacs( --daemon| -f znc-all)' ||:
 292
 293 if [[ -e /p/profanity-here ]]; then
 294   systemctl disable --now profanity
 295 fi
 296 EOF
 297 fi
 298
 299 # previously, I was checking to see if the new mail host
 300 # is on my home network, then changing my home dns
 301 # to resolve on the local network, so that I didnt
 302 # have to send traffic out to the internet or rely
 303 # on that. However, that breaks for a laptop that roams.
 304 # So, we could have a cronjob that updates that dns,
 305 # however, another solution is to just use ipv6,
 306 # and I prefer that.
 307 #
 308 # TODO: enable ipv6 for email. exim config setting disables it.
 309 # need to add vpn support. need to add firewall / routing.
 310 # I think exim will try ipv6 first, so no need to disable
 311 # ipv6 i think.
 312
 313
 314 e Running initial btrbk
 315 m btrbk-run -v $bbk_args $force_arg $incremental_arg $mp_args $snapshot_arg || ret=$?
 316 if (( ret )); then
 317   err "failed initial btrbk"
 318   exit $ret
 319 fi
 320
 321 if ! $mail_only; then
 322   m $old_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 323   m $new_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 324 fi
 325
 326 if $host2_only; then
 327   if [[ $old_hostname != "$MAIL_HOST" && $old_hostname != kd ]]; then
 328     m $old_shell systemctl --now disable btrbk.timer
 329   fi
 330   m $new_shell systemctl --now enable btrbk.timer
 331   if [[ -e /p/profanity-here ]]; then
 332     m $new_shell systemctl --now enable profanity
 333   fi
 334   exit 0
 335 fi
 336
 337 m $old_shell /a/exe/primary-setup $new_hostname || ret=$?
 338 if (( ret )); then
 339   err "failed \$old_shell primary-setup \$new_hostname. fix and rerun $script_name"
 340   exit $ret
 341 fi
 342
 343
 344 e Running main btrbk
 345 m btrbk-run -v --fast $bbk_args $force_arg $incremental_arg -m /o || ret=$?
 346 if (( ret )); then
 347   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 348   e $bang failed btrbk of /o. restoring old host as primary
 349   m $old_shell /a/exe/primary-setup localhost
 350   exit $ret
 351 fi
 352
 353 # new system is usable at this point
 354 blocks=██████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████
 355 printf "%s\n" "$(tput setaf 5 2>/dev/null ||:)${blocks:0:${COLUMNS:-180}}$(tput sgr0 2>/dev/null||:)"
 356
 357 # once I accidentally accepted incoming mail on old host. I used this script to copy over that mail:
 358 #
 359 # 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
 360
 361 # 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
 362 #
 363 # 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
 364
 365 m $new_shell /a/exe/primary-setup localhost || ret=$?
 366 if (( ret )); then
 367   err "failed final primary-setup, just fix and rerun: $new_shell /a/exe/primary-setup localhost"
 368   exit $ret
 369 fi
 370
 371 if ! $mail_only && [[ -e /p/profanity-here ]]; then
 372   m $new_shell systemctl --now enable profanity || ret=$?
 373   if (( ret )); then
 374     err "failed final systemctl --now enable profanity, just fix and rerun"
 375     exit $ret
 376   fi
 377 fi
 378
 379 m exit 0