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 -i         Disallow incremental backup.
  14 -o         Only btrbk /o, instead of all filesystems.
  15 --force    Run even though our local state does not say that MAIL_HOST is
  16            us when pushing or HOST when pulling.
  17 -h|--help  Print help and exit.
  18
  19 I used to adjust home network dns so NEW_HOST resolves locally if it is
  20 on the local network, but its simpler just not to and just rely
  21 on the internet. Email can wait.
  22
  23 Note: Uses GNU getopt options parsing style
  24 EOF
  25   exit $1
  26 }
  27
  28 script_name="${BASH_SOURCE[0]}"
  29 script_name="${script_name##*/}"
  30
  31 restore_new_btrbk=false
  32 restore_old_btrbk=false
  33 err-cleanup() {
  34   if $restore_new_btrbk; then
  35     e WARNING: due to failure, btrbk.timer may need manual restoration:
  36     e $new_shell systemctl start btrbk.timer
  37   fi
  38   if $restore_old_btrbk; then
  39     e WARNING: due to failure, btrbk.timer may need manual restoration:
  40     e $old_shell systemctl start btrbk.timer
  41   fi
  42 }
  43
  44 pre="${SSH_CLIENT:+$HOSTNAME} $script_name:"
  45 m() { printf "$pre %s\n"  "$*"; "$@"; }
  46 e() { printf "$pre %s\n"  "$*"; }
  47 err() { echo "$pre ERROR: $*" >&2; }
  48
  49 if [[ $EUID != 0 ]]; then
  50   err "requires running as root"
  51   exit 1
  52 fi
  53
  54
  55 ##### begin command line parsing ########
  56
  57 mail_only=false
  58 host2_only=false
  59 force=false
  60 mp_args="-m /o,/q,/a"
  61 temp=$(getopt -l force,help ioh "$@") || usage 1
  62 eval set -- "$temp"
  63 while true; do
  64   case $1 in
  65     --force) force=true ;;
  66     -i) incremental_arg="-i" ;;
  67     -o)
  68       mail_only=true ;;
  69     -h|--help) usage ;;
  70     --) shift; break ;;
  71     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  72   esac
  73   shift
  74 done
  75
  76
  77 (( $# == 2 )) || usage 1
  78
  79 if [[ ! $HOSTNAME ]]; then
  80   err "\$HOSTNAME is unset"
  81   exit 1
  82 fi
  83
  84 source /a/bin/bash_unpublished/source-state
  85
  86 direction=$1
  87 host=$2
  88 case $direction in
  89   push)
  90     old_host=$HOSTNAME
  91     old_hostname=$HOSTNAME
  92     new_host=$host
  93     bbk_args="-t $new_host"
  94     new_shell="ssh -F $HOME/.ssh/confighome root@$new_host"
  95     if ! new_hostname=$($new_shell hostname); then
  96       echo "$pre: error: failed ssh. retrying failed $new_shell with -v for more info:"
  97       $new_shell -v hostname
  98     fi
  99     ;;
 100   pull)
 101     old_host=$host
 102     new_host=$HOSTNAME
 103     new_hostname=$HOSTNAME
 104     bbk_args="-s $old_host"
 105     old_shell="ssh -F $HOME/.ssh/confighome root@$old_host"
 106     old_shelliank="ssh -F $HOME/.ssh/confighome iank@$old_host"
 107     # tests ssh connection. crafted this to not need to do escape chars
 108     f=/a/bin/bash_unpublished/source-state
 109     if ! old_info=($($old_shell "hostname; sed -n s,.*MAIL_HOST=,,p $f; sed -n s,.*HOST2=,,p $f")); then
 110       echo "$pre: error: failed ssh. retrying failed $old_shell with -v for more info:"
 111       $old_shell -v hostname
 112       exit 1
 113     fi
 114     old_hostname=${old_info[0]}
 115     MAIL_HOST=${old_info[1]}
 116     HOST2=${old_info[2]}
 117     ;;
 118   *)
 119     err invalid first argument
 120     exit 1
 121     ;;
 122 esac
 123
 124 case $script_name in
 125   switch-mail-host)
 126     if [[ $MAIL_HOST != "$HOST2" ]]; then
 127       mail_only=true
 128     fi
 129     ;;
 130   switch-host2)
 131     host2_only=true
 132     ;;
 133   *)
 134     err unexpected script name
 135     ;;
 136 esac
 137
 138 if $mail_only; then
 139   mp_args="-m /o"
 140 elif $host2_only; then
 141   mp_args="-m /a,/ar,/q,/qr"
 142 fi
 143
 144
 145 if $host2_only; then
 146   if [[ $old_hostname != "$HOST2" ]]; then
 147     err "\$old_hostname($old_hostname) != \$HOST2($HOST2). Rerun with --force if you really want this."
 148     exit 1
 149   fi
 150 elif [[ $old_hostname != "$MAIL_HOST" ]] && ! $force; then
 151   err "\$old_hostname($old_hostname) != \$MAIL_HOST($MAIL_HOST). Rerun with --force if you really want this."
 152   exit 1
 153 fi
 154
 155 if [[ ! $new_host || ! $old_host ]]; then
 156   echo "$0: bad args. see script"
 157   exit 1
 158 fi
 159
 160
 161 ########### end initial processing, begin actually modifying things ##########
 162
 163 if $new_shell systemctl is-active btrbk.timer; then
 164   m $new_shell systemctl stop btrbk.timer
 165   restore_new_btrbk=true
 166 fi
 167 if $old_shell systemctl is-active btrbk.timer; then
 168   m $old_shell systemctl stop btrbk.timer
 169   restore_old_btrbk=true
 170 fi
 171
 172 btrbk_test="systemctl is-active btrbk.service"
 173 active=true
 174 while $active; do
 175   active=false
 176   for shell in "$new_shell" "$old_shell"; do
 177     e $shell $btrbk_test
 178     status=$($shell $btrbk_test) ||:
 179     case $status in
 180       inactive|failed) : ;;
 181       *)
 182         # This covers conditions like "activating", which still return 3 from
 183         # systemctl is-active.
 184         active=true
 185         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 186         sleep 8
 187         break
 188         ;;
 189     esac
 190   done
 191 done
 192
 193 # ensure these are unused before doing anything
 194 e "On $new_host: umounting /m and /o, checking emacs"
 195 {
 196   cat <<'EOF'
 197 set -eE
 198 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 199   bufs="$(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/)"$//')"
 200   if [[ $bufs ]]; then
 201     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 202     exit 1
 203   fi
 204 fi
 205 EOF
 206   if ! $host2_only; then
 207     cat <<'EOF'
 208 for dir in m o; do
 209   if mountpoint -q /$dir; then
 210     echo On $new_host: umount /$dir
 211     umount /$dir
 212   fi
 213 done
 214 EOF
 215   fi
 216 } | $new_shell bash -s
 217
 218 $old_shell bash -s <<'EOF'
 219 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 220   bufs="$(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/)"$//')"
 221   if [[ $bufs ]]; then
 222     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 223     exit 1
 224   fi
 225 fi
 226 EOF
 227
 228 # previously, I was checking to see if the new mail host
 229 # is on my home network, then changing my home dns
 230 # to resolve on the local network, so that I didnt
 231 # have to send traffic out to the internet or rely
 232 # on that. However, that breaks for a laptop that roams.
 233 # So, we could have a cronjob that updates that dns,
 234 # however, another solution is to just use ipv6,
 235 # and I prefer that.
 236 #
 237 # TODO: enable ipv6 for email. exim config setting disables it.
 238 # need to add vpn support. need to add firewall / routing.
 239 # I think exim will try ipv6 first, so no need to disable
 240 # ipv6 i think.
 241
 242
 243 e Running initial btrbk
 244 if ! m btrbk-run -v $bbk_args $incremental_arg $mp_args; then
 245   ret=$?
 246   err "failed initial btrbk"
 247   exit $ret
 248 fi
 249
 250 if ! $mail_only; then
 251   m $old_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 252   m $new_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 253 fi
 254
 255 if $host2_only; then
 256   if [[ $old_hostname != "$MAIL_HOST" && $old_hostname != kd ]]; then
 257     m $old_shell systemctl --now disable btrbk.timer
 258   fi
 259   m $new_shell systemctl --now enable btrbk.timer
 260   exit 0
 261 fi
 262
 263 if ! m $old_shell /a/exe/primary-setup $new_hostname; then
 264   ret=$?
 265   err "failed \$old_shell primary-setup \$new_hostname. fix and rerun $script_name"
 266   exit $ret
 267 fi
 268
 269 # Try to prevent emacs from saving stale data it has in memory to disk. eg: files, recentf list, etc.
 270 # But if emacs ignores the signal, let it live.
 271 m $new_shell killall -q emacs ||:
 272
 273 e Running main btrbk
 274 m btrbk-run -v $bbk_args $incremental_arg -m /o || ret=$?
 275 if (( ret )); then
 276   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 277   e $bang failed btrbk of /o. restoring old host as primary
 278   m $old_shell /a/exe/primary-setup localhost
 279   exit $ret
 280 fi
 281
 282 # new system is usable at this point
 283 printf "$(tput setaf 5 2>/dev/null ||:)█$(tput sgr0 2>/dev/null||:)%.0s" $(eval echo "{1..${COLUMNS:-60}}")
 284 echo
 285
 286 # once I accidentally accepted incoming mail on old host. I used this script to copy over that mail:
 287 #
 288 # 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
 289
 290 # 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
 291 #
 292 # 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
 293
 294 if ! m $new_shell /a/exe/primary-setup localhost; then
 295   ret=$?
 296   err "failed final primary-setup, just fix and rerun: $new_shell /a/exe/primary-setup localhost"
 297   exit $ret
 298 fi
 299
 300 m exit 0