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 "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     f=/a/bin/bash_unpublished/source-state
 158     if ! old_info=$($old_shell "hostname; sed -n s,.*MAIL_HOST=,,p $f; sed -n s,.*HOST2=,,p $f"); then
 159       echo "$pre: error: failed ssh. retrying failed $old_shell with -v for more info:"
 160       $old_shell -v hostname
 161       exit 1
 162     fi
 163     IFS=" " read -r old_hostname MAIL_HOST HOST2 <<<"$old_info"
 164
 165     if ! $mail_only && ! $pull_reexec ; then
 166       if ! $force; then
 167         $old_shell switch-mail-host --check-installed
 168       fi
 169       tmpf=$(mktemp)
 170       m scp -F $HOME/.ssh/confighome root@$old_host:/usr/local/bin/switch-mail-host $tmpf
 171       if ! diff -q $tmpf ${BASH_SOURCE[0]}; then
 172         e "found different version on old_host=$old_hostname, reexecing"
 173         m install -T $tmpf /usr/local/bin/switch-mail-host
 174         m /usr/local/bin/switch-mail-host --pull-reexec "${orig_args[@]}"
 175         mexit 0
 176       fi
 177     fi
 178
 179     ;;
 180   *)
 181     err invalid first argument
 182     exit 1
 183     ;;
 184 esac
 185
 186 case $script_name in
 187   switch-mail-host)
 188     if [[ $MAIL_HOST != "$HOST2" ]]; then
 189       mail_only=true
 190     fi
 191     ;;
 192   switch-host2)
 193     host2_only=true
 194     ;;
 195   *)
 196     err unexpected script name
 197     ;;
 198 esac
 199
 200 if $mail_only; then
 201   mp_args="-m /o"
 202 elif $host2_only; then
 203   mp_args="-m /a,/ar,/q,/qd,/qr"
 204 fi
 205
 206 if ! $force; then
 207   if $host2_only; then
 208     if [[ $old_hostname != "$HOST2" ]]; then
 209       err "\$old_hostname($old_hostname) != \$HOST2($HOST2). Rerun with --force if you really want this."
 210       exit 1
 211     fi
 212   elif [[ $old_hostname != "$MAIL_HOST" ]]; then
 213     err "\$old_hostname($old_hostname) != \$MAIL_HOST($MAIL_HOST). Rerun with --force if you really want this."
 214     exit 1
 215   fi
 216 fi
 217
 218 if [[ ! $new_host || ! $old_host ]]; then
 219   echo "$0: bad args. see script"
 220   exit 1
 221 fi
 222
 223
 224 ########### end initial processing, begin actually modifying things ##########
 225
 226 if $new_shell systemctl is-active btrbk.timer; then
 227   m $new_shell systemctl stop btrbk.timer
 228   restore_new_btrbk=true
 229 fi
 230 if $old_shell systemctl is-active btrbk.timer; then
 231   m $old_shell systemctl stop btrbk.timer
 232   restore_old_btrbk=true
 233 fi
 234
 235 btrbk_test="systemctl is-active btrbk.service"
 236 active=true
 237 while $active; do
 238   active=false
 239   for shell in "$new_shell" "$old_shell"; do
 240     e $shell $btrbk_test
 241     status=$($shell $btrbk_test) ||:
 242     case $status in
 243       inactive|failed) : ;;
 244       *)
 245         # This covers conditions like "activating", which still return 3 from
 246         # systemctl is-active.
 247         active=true
 248         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 249         sleep 8
 250         break
 251         ;;
 252     esac
 253   done
 254 done
 255
 256 # ensure these are unused before doing anything
 257 e "On $new_host: umounting /m and /o, checking emacs"
 258 {
 259   cat <<'EOF'
 260 set -eE
 261 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 262   bufs="$(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/)"$//')"
 263   if [[ $bufs ]]; then
 264     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 265     exit 1
 266   fi
 267 fi
 268 EOF
 269   if ! $host2_only; then
 270     cat <<EOF
 271 for dir in m o; do
 272   if mountpoint -q /\$dir; then
 273     echo On $new_host: umount /\$dir
 274     umount /\$dir
 275   fi
 276 done
 277 EOF
 278   fi
 279 } | $new_shell bash -s
 280
 281 $old_shell bash -s <<'EOF'
 282 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 283   bufs="$(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/)"$//')"
 284   if [[ $bufs ]]; then
 285     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 286     exit 1
 287   fi
 288 fi
 289 EOF
 290
 291 # previously, I was checking to see if the new mail host
 292 # is on my home network, then changing my home dns
 293 # to resolve on the local network, so that I didnt
 294 # have to send traffic out to the internet or rely
 295 # on that. However, that breaks for a laptop that roams.
 296 # So, we could have a cronjob that updates that dns,
 297 # however, another solution is to just use ipv6,
 298 # and I prefer that.
 299 #
 300 # TODO: enable ipv6 for email. exim config setting disables it.
 301 # need to add vpn support. need to add firewall / routing.
 302 # I think exim will try ipv6 first, so no need to disable
 303 # ipv6 i think.
 304
 305
 306 e Running initial btrbk
 307 m btrbk-run -v $bbk_args $force_arg $incremental_arg $mp_args $snapshot_arg || ret=$?
 308 if (( ret )); then
 309   err "failed initial btrbk"
 310   exit $ret
 311 fi
 312
 313 if ! $mail_only; then
 314   m $old_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 315   m $new_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 316 fi
 317
 318 if $host2_only; then
 319   if [[ $old_hostname != "$MAIL_HOST" && $old_hostname != kd ]]; then
 320     m $old_shell systemctl --now disable btrbk.timer
 321   fi
 322   m $new_shell systemctl --now enable btrbk.timer
 323   exit 0
 324 fi
 325
 326 m $old_shell /a/exe/primary-setup $new_hostname || ret=$?
 327 if (( ret )); then
 328   err "failed \$old_shell primary-setup \$new_hostname. fix and rerun $script_name"
 329   exit $ret
 330 fi
 331
 332 # Try to prevent emacs from saving stale data it has in memory to disk. eg: files, recentf list, etc.
 333 # But if emacs ignores the signal, let it live.
 334 m $new_shell killall -q emacs ||:
 335
 336 e Running main btrbk
 337 m btrbk-run -v --fast $bbk_args $force_arg $incremental_arg -m /o || ret=$?
 338 if (( ret )); then
 339   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 340   e $bang failed btrbk of /o. restoring old host as primary
 341   m $old_shell /a/exe/primary-setup localhost
 342   exit $ret
 343 fi
 344
 345 # new system is usable at this point
 346 printf "$(tput setaf 5 2>/dev/null ||:)█$(tput sgr0 2>/dev/null||:)%.0s $(eval echo "{1..${COLUMNS:-60}}")"
 347 echo
 348
 349 # once I accidentally accepted incoming mail on old host. I used this script to copy over that mail:
 350 #
 351 # 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
 352
 353 # 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
 354 #
 355 # 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
 356
 357 m $new_shell /a/exe/primary-setup localhost || ret=$?
 358 if (( ret )); then
 359   err "failed final primary-setup, just fix and rerun: $new_shell /a/exe/primary-setup localhost"
 360   exit $ret
 361 fi
 362
 363 m exit 0