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 $1
  30 }
  31
  32 script_name="${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 $old_shell systemctl start btrbk.timer
  45   fi
  46 }
  47
  48 pre="${SSH_CLIENT:+$HOSTNAME} $script_name:"
  49 m() { printf "$pre %s\n"  "$*"; "$@"; }
  50 e() { printf "$pre %s\n"  "$*"; }
  51 err() { echo "$pre ERROR: $*" >&2; }
  52
  53 if [[ $EUID != 0 ]]; then
  54   err "requires running as root"
  55   exit 1
  56 fi
  57
  58
  59 ##### begin command line parsing ########
  60
  61 mail_only=false
  62 host2_only=false
  63 force=false
  64 pull_reexec=false
  65 mp_args="-m /o,/a,/ar,/q,/qd,/qr"
  66 orig_args=("$@")
  67 temp=$(getopt -l force,pull-reexec,help aioh "$@") || usage 1
  68 eval set -- "$temp"
  69 while true; do
  70   case $1 in
  71     -a) snapshot_arg=resume ;;
  72     --force) force=true ;;
  73     -i) incremental_arg="-i" ;;
  74     # internal option for rerunning under newer old_host when doing pull
  75     --pull-reexec) pull_reexec=true;;
  76     -o)
  77       mail_only=true ;;
  78     -h|--help) usage ;;
  79     --) shift; break ;;
  80     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  81   esac
  82   shift
  83 done
  84
  85
  86 (( $# == 2 )) || usage 1
  87
  88 if [[ ! $HOSTNAME ]]; then
  89   err "\$HOSTNAME is unset"
  90   exit 1
  91 fi
  92
  93 uninstalled-file-die() {
  94   err "uninstalled file $1. run install-my-scripts or rerun with -f"
  95   exit 1
  96 }
  97
  98 if ! $force; then
  99   install_bin_files=(
 100     mount-latest-subvol
 101     check-subvol-stale
 102     btrbk-run
 103     switch-mail-host
 104   )
 105   for f in ${install_bin_files[@]}; do
 106     if ! diff -q /a/bin/ds/$f /usr/local/bin/$f; then
 107       uninstalled-file-die $f
 108     fi
 109   done
 110   if ! diff -q /a/bin/errhandle/err /usr/local/lib/err; then
 111     uninstalled-file-die err
 112   fi
 113 fi
 114
 115 source /a/bin/bash_unpublished/source-state
 116
 117 direction=$1
 118 host=$2
 119 case $direction in
 120   push)
 121     old_host=$HOSTNAME
 122     old_hostname=$HOSTNAME
 123     new_host=$host
 124     bbk_args="-t $new_host"
 125     new_shell="ssh -F $HOME/.ssh/confighome root@$new_host"
 126     if ! new_hostname=$($new_shell hostname); then
 127       echo "$pre: error: failed ssh. retrying failed $new_shell with -v for more info:"
 128       $new_shell -v hostname
 129     fi
 130     ;;
 131   pull)
 132     old_host=$host
 133     new_host=$HOSTNAME
 134     new_hostname=$HOSTNAME
 135     bbk_args="-s $old_host"
 136     old_shell="ssh -F $HOME/.ssh/confighome root@$old_host"
 137     # tests ssh connection. crafted this to not need to do escape chars
 138     f=/a/bin/bash_unpublished/source-state
 139     if ! old_info=($($old_shell "hostname; sed -n s,.*MAIL_HOST=,,p $f; sed -n s,.*HOST2=,,p $f")); then
 140       echo "$pre: error: failed ssh. retrying failed $old_shell with -v for more info:"
 141       $old_shell -v hostname
 142       exit 1
 143     fi
 144     old_hostname=${old_info[0]}
 145     MAIL_HOST=${old_info[1]}
 146     HOST2=${old_info[2]}
 147
 148     if ! $mail_only && ! $pull_reexec ; then
 149       tmpf=$(mktemp)
 150       m scp -F $HOME/.ssh/confighome root@$old_host:/usr/local/bin/switch-mail-host $tmpf
 151       if ! diff -q $tmpf ${BASH_SOURCE[0]}; then
 152         e "found different version on old_host=$old_hostname, reexecing"
 153         install -T $tmpf /usr/local/bin/switch-mail-host
 154         m /usr/local/bin/switch-mail-host --pull-reexec "${orig_args[@]}"
 155         mexit 0
 156       fi
 157     fi
 158
 159     ;;
 160   *)
 161     err invalid first argument
 162     exit 1
 163     ;;
 164 esac
 165
 166 case $script_name in
 167   switch-mail-host)
 168     if [[ $MAIL_HOST != "$HOST2" ]]; then
 169       mail_only=true
 170     fi
 171     ;;
 172   switch-host2)
 173     host2_only=true
 174     ;;
 175   *)
 176     err unexpected script name
 177     ;;
 178 esac
 179
 180 if $mail_only; then
 181   mp_args="-m /o"
 182 elif $host2_only; then
 183   mp_args="-m /a,/ar,/q,/qd,/qr"
 184 fi
 185
 186 if ! $force; then
 187   if $host2_only; then
 188     if [[ $old_hostname != "$HOST2" ]]; then
 189       err "\$old_hostname($old_hostname) != \$HOST2($HOST2). Rerun with --force if you really want this."
 190       exit 1
 191     fi
 192   elif [[ $old_hostname != "$MAIL_HOST" ]]; then
 193     err "\$old_hostname($old_hostname) != \$MAIL_HOST($MAIL_HOST). Rerun with --force if you really want this."
 194     exit 1
 195   fi
 196 fi
 197
 198 if [[ ! $new_host || ! $old_host ]]; then
 199   echo "$0: bad args. see script"
 200   exit 1
 201 fi
 202
 203
 204 ########### end initial processing, begin actually modifying things ##########
 205
 206 if $new_shell systemctl is-active btrbk.timer; then
 207   m $new_shell systemctl stop btrbk.timer
 208   restore_new_btrbk=true
 209 fi
 210 if $old_shell systemctl is-active btrbk.timer; then
 211   m $old_shell systemctl stop btrbk.timer
 212   restore_old_btrbk=true
 213 fi
 214
 215 btrbk_test="systemctl is-active btrbk.service"
 216 active=true
 217 while $active; do
 218   active=false
 219   for shell in "$new_shell" "$old_shell"; do
 220     e $shell $btrbk_test
 221     status=$($shell $btrbk_test) ||:
 222     case $status in
 223       inactive|failed) : ;;
 224       *)
 225         # This covers conditions like "activating", which still return 3 from
 226         # systemctl is-active.
 227         active=true
 228         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 229         sleep 8
 230         break
 231         ;;
 232     esac
 233   done
 234 done
 235
 236 # ensure these are unused before doing anything
 237 e "On $new_host: umounting /m and /o, checking emacs"
 238 {
 239   cat <<'EOF'
 240 set -eE
 241 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 242   bufs="$(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/)"$//')"
 243   if [[ $bufs ]]; then
 244     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 245     exit 1
 246   fi
 247 fi
 248 EOF
 249   if ! $host2_only; then
 250     cat <<EOF
 251 for dir in m o; do
 252   if mountpoint -q /\$dir; then
 253     echo On $new_host: umount /\$dir
 254     umount /\$dir
 255   fi
 256 done
 257 EOF
 258   fi
 259 } | $new_shell bash -s
 260
 261 $old_shell bash -s <<'EOF'
 262 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 263   bufs="$(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/)"$//')"
 264   if [[ $bufs ]]; then
 265     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 266     exit 1
 267   fi
 268 fi
 269 EOF
 270
 271 # previously, I was checking to see if the new mail host
 272 # is on my home network, then changing my home dns
 273 # to resolve on the local network, so that I didnt
 274 # have to send traffic out to the internet or rely
 275 # on that. However, that breaks for a laptop that roams.
 276 # So, we could have a cronjob that updates that dns,
 277 # however, another solution is to just use ipv6,
 278 # and I prefer that.
 279 #
 280 # TODO: enable ipv6 for email. exim config setting disables it.
 281 # need to add vpn support. need to add firewall / routing.
 282 # I think exim will try ipv6 first, so no need to disable
 283 # ipv6 i think.
 284
 285
 286 e Running initial btrbk
 287 m btrbk-run -v $bbk_args $incremental_arg $mp_args $snapshot_arg || ret=$?
 288 if (( ret )); then
 289   err "failed initial btrbk"
 290   exit $ret
 291 fi
 292
 293 if ! $mail_only; then
 294   m $old_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 295   m $new_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 296 fi
 297
 298 if $host2_only; then
 299   if [[ $old_hostname != "$MAIL_HOST" && $old_hostname != kd ]]; then
 300     m $old_shell systemctl --now disable btrbk.timer
 301   fi
 302   m $new_shell systemctl --now enable btrbk.timer
 303   exit 0
 304 fi
 305
 306 m $old_shell /a/exe/primary-setup $new_hostname || ret=$?
 307 if (( ret )); then
 308   err "failed \$old_shell primary-setup \$new_hostname. fix and rerun $script_name"
 309   exit $ret
 310 fi
 311
 312 # Try to prevent emacs from saving stale data it has in memory to disk. eg: files, recentf list, etc.
 313 # But if emacs ignores the signal, let it live.
 314 m $new_shell killall -q emacs ||:
 315
 316 e Running main btrbk
 317 m btrbk-run -v --fast $bbk_args $incremental_arg -m /o || ret=$?
 318 if (( ret )); then
 319   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 320   e $bang failed btrbk of /o. restoring old host as primary
 321   m $old_shell /a/exe/primary-setup localhost
 322   exit $ret
 323 fi
 324
 325 # new system is usable at this point
 326 printf "$(tput setaf 5 2>/dev/null ||:)█$(tput sgr0 2>/dev/null||:)%.0s" $(eval echo "{1..${COLUMNS:-60}}")
 327 echo
 328
 329 # once I accidentally accepted incoming mail on old host. I used this script to copy over that mail:
 330 #
 331 # 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
 332
 333 # 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
 334 #
 335 # 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
 336
 337 m $new_shell /a/exe/primary-setup localhost || ret=$?
 338 if (( ret )); then
 339   err "failed final primary-setup, just fix and rerun: $new_shell /a/exe/primary-setup localhost"
 340   exit $ret
 341 fi
 342
 343 m exit 0