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 $old_shell systemctl start btrbk.timer
  41   fi
  42 }
  43
  44 pre="$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     $new_shell -v hostname
  96     new_hostname=$($new_shell hostname)
  97     ;;
  98   pull)
  99     old_host=$host
 100     new_host=$HOSTNAME
 101     new_hostname=$HOSTNAME
 102     bbk_args="-s $old_host"
 103     old_shell="ssh -F $HOME/.ssh/confighome root@$old_host"
 104     # tests ssh connection. crafted this to not need to do escape chars
 105     f=/a/bin/bash_unpublished/source-state
 106     if ! old_info=($($old_shell "hostname; sed -n s,.*MAIL_HOST=,,p $f; sed -n s,.*HOST2=,,p $f")); then
 107       echo "$pre: error: failed ssh. retrying failed $old_shell with -v for more info:"
 108       $old_shell -v hostname
 109       exit 1
 110     fi
 111     old_hostname=${old_info[0]}
 112     MAIL_HOST=${old_info[1]}
 113     HOST2=${old_info[2]}
 114     ;;
 115   *)
 116     err invalid first argument
 117     exit 1
 118     ;;
 119 esac
 120
 121 case $script_name in
 122   switch-mail-host)
 123     if [[ $MAIL_HOST != "$HOST2" ]]; then
 124       mail_only=true
 125     fi
 126     ;;
 127   switch-host2)
 128     host2_only=true
 129     ;;
 130   *)
 131     err unexpected script name
 132     ;;
 133 esac
 134
 135
 136 if $mail_only; then
 137   mp_args="-m /o"
 138 elif $host2_only; then
 139   mp_args="-m /a,/ar,/q,/qr"
 140 fi
 141
 142
 143
 144 if [[ $old_hostname != "$MAIL_HOST" ]] && ! $force; then
 145   err "\$old_hostname($old_hostname) != \$MAIL_HOST($MAIL_HOST). Rerun with --force if you really want this."
 146   exit 1
 147 fi
 148
 149 if [[ ! $new_host || ! $old_host ]]; then
 150   echo "$0: bad args. see script"
 151   exit 1
 152 fi
 153
 154
 155 ########### end initial processing, begin actually modifying things ##########
 156
 157 if $new_shell systemctl is-active btrbk.timer; then
 158   m $new_shell systemctl stop btrbk.timer
 159   restore_new_btrbk=true
 160 fi
 161 if $old_shell systemctl is-active btrbk.timer; then
 162   m $old_shell systemctl stop btrbk.timer
 163   restore_old_btrbk=true
 164 fi
 165
 166 btrbk_test="systemctl is-active btrbk.service"
 167 active=true
 168 while $active; do
 169   active=false
 170   for shell in "$new_shell" "$old_shell"; do
 171     e $shell $btrbk_test
 172     status=$($shell $btrbk_test) ||:
 173     case $status in
 174       inactive|failed) : ;;
 175       *)
 176         # This covers conditions like "activating", which still return 3 from
 177         # systemctl is-active.
 178         active=true
 179         e "btrbk active on shell:$shell, status:$status, sleeping 8 seconds"
 180         sleep 8
 181         break
 182         ;;
 183     esac
 184   done
 185 done
 186
 187 # ensure these are unused before doing anything
 188 e "On $new_host: umounting /m and /o, checking emacs"
 189 {
 190   cat <<'EOF'
 191 set -eE
 192 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 193   export XDG_RUNTIME_DIR=/run/user/1000
 194   bufs="$(emacsclient --eval "$(cat /a/bin/ds/unsaved-buffers.el)"| sed '/^"nil"$/d;s/^"(/E: /;s/)"$//')"
 195   if [[ $bufs ]]; then
 196     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 197     exit 1
 198   fi
 199 fi
 200 EOF
 201   if ! $host2_only; then
 202     cat <<'EOF'
 203 for dir in m o; do
 204   if mountpoint -q /$dir; then
 205     echo On $new_host: umount /$dir
 206     umount /$dir
 207   fi
 208 done
 209 EOF
 210   fi
 211 } | $new_shell bash -s
 212
 213 $old_shell bash -s <<'EOF'
 214 if pgrep -G iank -u iank -f 'emacs --daemon' &>/dev/null; then
 215   export XDG_RUNTIME_DIR=/run/user/1000
 216   bufs="$(emacsclient --eval "$(cat /a/bin/ds/unsaved-buffers.el)"| sed '/^"nil"$/d;s/^"(/E: /;s/)"$//')"
 217   if [[ $bufs ]]; then
 218     echo "error: on $HOSTNAME, unsaved emacs files: $bufs" >&2
 219     exit 1
 220   fi
 221 fi
 222 EOF
 223
 224 # previously, I was checking to see if the new mail host
 225 # is on my home network, then changing my home dns
 226 # to resolve on the local network, so that I didnt
 227 # have to send traffic out to the internet or rely
 228 # on that. However, that breaks for a laptop that roams.
 229 # So, we could have a cronjob that updates that dns,
 230 # however, another solution is to just use ipv6,
 231 # and I prefer that.
 232 #
 233 # TODO: enable ipv6 for email. exim config setting disables it.
 234 # need to add vpn support. need to add firewall / routing.
 235 # I think exim will try ipv6 first, so no need to disable
 236 # ipv6 i think.
 237
 238
 239 e Running initial btrbk
 240 if ! m btrbk-run -v $bbk_args $incremental_arg $mp_args; then
 241   ret=$?
 242   err "failed initial btrbk"
 243   exit $ret
 244 fi
 245
 246 if ! $mail_only; then
 247   m $old_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 248   m $new_shell sed -ri "s/HOST2=.*/HOST2=$new_hostname/" /a/bin/bash_unpublished/source-state
 249 fi
 250
 251 if $host2_only; then
 252   exit 0
 253 fi
 254
 255 if ! m $old_shell /a/exe/primary-setup $new_hostname; then
 256   ret=$?
 257   err "failed \$old_shell primary-setup \$new_hostname. fix and rerun $script_name"
 258   exit $ret
 259 fi
 260
 261 # Try to prevent emacs from saving stale data it has in memory to disk. eg: files, recentf list, etc.
 262 # But if emacs ignores the signal, let it live.
 263 m $new_shell killall -q emacs ||:
 264
 265 e Running main btrbk
 266 m btrbk-run -v $bbk_args $incremental_arg -m /o || ret=$?
 267 if (( ret )); then
 268   bang="$(printf "$(tput setaf 5)█$(tput sgr0)%.0s" 1 2 3 4 5 6 7)"
 269   e $bang failed btrbk of /o. restoring old host as primary
 270   m $old_shell /a/exe/primary-setup localhost
 271   exit $ret
 272 fi
 273
 274 # once I accidentally accepted incoming mail on old host. I used this script to copy over that mail:
 275 #
 276 # 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
 277
 278 # 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
 279 #
 280 # 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
 281
 282 if ! m $new_shell /a/exe/primary-setup localhost; then
 283   ret=$?
 284   err "failed final primary-setup, just fix and rerun: $new_shell /a/exe/primary-setup localhost"
 285   exit $ret
 286 fi
 287
 288 m exit 0