From 41b0266eb94d37f2264256897956ba4c1c6a04d6 Mon Sep 17 00:00:00 2001
From: Ian Kelling <ian@iankelling.org>
Date: Thu, 1 Aug 2019 23:43:23 -0400
Subject: [PATCH] more verbose and robust btrbk wrappers

---
 btrbk-run        |   2 +-
 switch-mail-host | 129 ++++++++++++++++++++++++++++-------------------
 2 files changed, 79 insertions(+), 52 deletions(-)

diff --git a/btrbk-run b/btrbk-run
index f6570a1..5c14398 100644
--- a/btrbk-run
+++ b/btrbk-run
@@ -85,6 +85,7 @@ rsync-dirs() {
 }
 
 
+pre="${0##*/}:"
 m() { if $verbose; then printf "$pre %s\n"  "$*"; fi;  "$@"; }
 die() { printf "$pre %s\n" "$*" >&2;  exit 1; }
 
@@ -116,7 +117,6 @@ if [[ -s $default_args_file ]]; then
   sleep 5
 fi
 
-pre="${0##*/}:"
 cron=false
 orig_args=("$@")
 temp=$(getopt -l cron,pull-reexec,help cl:m:npqs:t:vh "$@") || usage 1
diff --git a/switch-mail-host b/switch-mail-host
index 2d74ceb..e52abdb 100644
--- a/switch-mail-host
+++ b/switch-mail-host
@@ -1,35 +1,95 @@
 #!/bin/bash
-set -x
-set -eE -o pipefail
-trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
+
+err-bash-trace() {
+  local -i argc_index=0 frame i start=${1:-0} max_indent=8 indent
+  local source
+  local extdebug=false
+  if [[ $(shopt -p extdebug) == *-s* ]]; then
+    extdebug=true
+  fi
+  for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
+    argc=${BASH_ARGC[frame]}
+    argc_index+=$argc
+    ((frame < start)) && continue
+    if (( ${#BASH_SOURCE[@]} > 1 )); then
+      source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
+    fi
+    indent=$((frame-start + 1))
+    indent=$((indent < max_indent ? indent : max_indent))
+    printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
+    if $extdebug; then
+      for ((i=argc_index-1; i >= argc_index-argc; i--)); do
+        printf " %s" "${BASH_ARGV[i]}"
+      done
+    fi
+    echo \'
+  done
+  return 0
+}
+
+
+err-catch() {
+  set -E; shopt -s extdebug
+  _err-trap() {
+    err=$?
+    exec >&2
+    set +x
+    echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}: \`$BASH_COMMAND' returned $err"
+    err-bash-trace 2
+    set -e # err trap does not work within an error trap
+    "${_errcatch_cleanup[@]:-:}" # note :-: is to be compatible with set -u
+    echo "$0: exiting with code $err"
+    exit $err
+  }
+  trap _err-trap ERR
+  set -o pipefail
+}
+err-catch
 
 usage() {
   cat <<EOF
 Usage: ${0##*/} OLD_HOST NEW_HOST
 
-Adjust home network dns so NEW_HOST resolves locally if it is on the
-local network.  Turn off mail receiving on OLD_HOST, run btrbk to move
-mail to NEW_HOST, turn on mail receiving on NEW_HOST.
+Turn off mail receiving on OLD_HOST, run btrbk to move mail to NEW_HOST,
+turn on mail receiving on NEW_HOST.  Assumes we want to move all
+filesystems unless passing -o.
 
 -o         Only btrbk /o, instead of all filesystems.
--w         Don't try to ssh to wrt. Should only be used in unusual network situation.
 -h|--help  Print help and exit.
 
+I used to adjust home network dns so NEW_HOST resolves locally if it is
+on the local network, but its simpler just not to and just rely
+on the internet. Email can wait.
+
 Note: Uses GNU getopt options parsing style
 EOF
   exit $1
 }
 
+restore_new_btrbk=false
+restore_old_btrbk=false
+cleanup() {
+  if $restore_new_btrbk; then
+    $new_shell sudo systemctl start btrbk.timer
+  fi
+  if $restore_old_btrbk; then
+    $old_shell sudo systemctl start btrbk.timer
+  fi
+}
+_errcatch_cleanup=cleanup
+
+pre="${0##*/}:"
+m() { printf "$pre %s\n"  "$*"; "$@"; }
+e() { printf "$pre %s\n"  "$*"; }
+
 ##### begin command line parsing ########
 
-update_wrt=true # default
 temp=$(getopt -l help owh "$@") || usage 1
 mp_args="-m /o,/q,/a"
 eval set -- "$temp"
 while true; do
   case $1 in
     -o) mp_args="-m /o"; shift ;;
-    -w) update_wrt=false; shift ;;
     -h|--help) usage ;;
     --) shift; break ;;
     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
@@ -68,48 +128,20 @@ if [[ ! $new_host || ! $old_host ]]; then
   exit 1
 fi
 
-at_home=false
-if timeout -s 9 5 ssh-keyscan -p 2220 -t rsa 10.0.0.1 2>/dev/null | grep -qFx '[10.0.0.1]:2220 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCH+/h1dGEfKEusBblndU2e6QT4wLCm5+yqr/sqh/0X9YfjR7BfWWm8nNmuP55cYc+Wuf5ljB1H1acXEcsl1y8e0j3agHfF0V74FE1N1zz5nn2Ep8NHnmqgEhza38ZxMPh+4p3X7zklEKU7+3SzybKBi8sg0wLzlS2LM0JaUN80zR2sK11Kye3dURUXPk78u5wodOkgcEYRwSYaDMJlUzWP+poRXIDJwFaMQnwmxbl/c84yOyaU0x/d6hFwoRscWecihX+vvBNeSyxR4xr2HDOyUWwJkctyAgt2p7w3tfkXOKcCRzTAjGVIMQLTvo0sG/yJbcyHoEFdFybCsgDvfyYn'; then
-  at_home=true
-fi
-echo "$0: at_home = $at_home"
 
 source /a/bin/bash_unpublished/source-state
-#### begin convert private hostnames to public hostnames ####
-#if ! $at_home; then
-#    for var in old_host new_host; do
-#        case ${!var} in
-#            tp)
-#                eval $var=$HOME_DOMAIN
-#                ;;
-#        esac
-#    done
-#fi
-####  end convert private hostnames to public hostnames ####
-
-
-# because our port forward is not robust enough, we can't use proxy command,
-# todo: setup vpn so this is all taken care of.
-if ! $update_wrt; then
-  wrt_shell=:
-else
-  wrt_shell="ssh wrt.b8.nz"
-fi
+
 
 new_hostname=$($new_shell hostname)
 
 ########### end initial processing, begin actually modifying things ##########
 
-restore_new_btrbk=false
 if $new_shell systemctl is-active btrbk.timer; then
-  $new_shell sudo systemctl stop btrbk.timer
-  echo "$0: note: stopped btrbk.timer on $new_host"
+  m $new_shell sudo systemctl stop btrbk.timer
   restore_new_btrbk=true
 fi
-restore_old_btrbk=false
 if $old_shell systemctl is-active btrbk.timer; then
-  $old_shell sudo systemctl stop btrbk.timer
-  echo "$0: note: stopped btrbk.timer on $old_host"
+  m $old_shell sudo systemctl stop btrbk.timer
   restore_old_btrbk=true
 fi
 
@@ -121,7 +153,9 @@ while [[ $($new_shell $btrbk_test) != inactive ]] || [[ $($old_shell $btrbk_test
   sleep 2
 done
 
+# ensure these are unused before doing anything
 
+e "umounting /m and /o via $new_shell"
 $new_shell bash -xs <<'EOF'
 set -eE
 if mountpoint -q /m; then sudo umount /m; fi
@@ -142,19 +176,12 @@ EOF
 # I think exim will try ipv6 first, so no need to disable
 # ipv6 i think.
 
-$old_shell /a/exe/primary-setup $new_hostname
+m $old_shell /a/exe/primary-setup $new_hostname
 
 if $localhost_new; then
-  btrbk-run -s $old_host $mp_args
+  m btrbk-run -v -s $old_host $mp_args
 else
-  btrbk-run -t $new_host $mp_args
+  m btrbk-run -v -t $new_host $mp_args
 fi
 
-$new_shell /a/exe/primary-setup $new_hostname
-
-if $restore_new_btrbk; then
-  $new_shell sudo systemctl start btrbk.timer
-fi
-if $restore_old_btrbk; then
-  $old_shell sudo systemctl start btrbk.timer
-fi
+m $new_shell /a/exe/primary-setup $new_hostname
-- 
2.30.2