iankelling.org Git - distro-setup/blob - switch-mail-host

   1 #!/bin/bash
   2 set -x
   3 set -eE -o pipefail
   4 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
   5
   6 usage() {
   7     cat <<EOF
   8 Usage: ${0##*/} OLD_HOST NEW_HOST
   9
  10 Adjust home network dns so NEW_HOST resolves locally if it is on the
  11 local network.  Turn off mail receiving on OLD_HOST, run btrbk to move
  12 mail to NEW_HOST, turn on mail receiving on NEW_HOST.
  13
  14
  15 -h|--help  Print help and exit.
  16
  17 Note: Uses GNU getopt options parsing style
  18 EOF
  19     exit $1
  20 }
  21
  22 ##### begin command line parsing ########
  23
  24 if (( $# != 2 )) || [[ $1 == -* || $2 == -* ]]; then
  25     usage 1
  26 fi
  27
  28 old_host=$1
  29 new_host=$2
  30
  31 if [[ $old_host != $MAIL_HOST ]]; then
  32     read -p "warning: \$old_host != \$MAIL_HOST: $old_host != $MAIL_HOST, proceed? y/N "
  33     if [[ $REPLY != [yY] ]]; then
  34         exit 1
  35     fi
  36 fi
  37
  38 if [[ $new_host == "$HOSTNAME" ]]; then
  39     localhost_new=true
  40     new_shell=
  41 else
  42     localhost_new=false
  43     new_shell="ssh $new_host"
  44 fi
  45
  46 old_shell="ssh $old_host"
  47 if [[ $old_host == "$HOSTNAME" ]]; then
  48     old_shell=
  49 fi
  50
  51 if [[ ! $new_host || ! $old_host ]]; then
  52     echo "$0: bad args. see script"
  53     exit 1
  54 fi
  55
  56 at_home=false
  57 if [[ $HOSTNAME == treetowl ]] || [[ $HOSTNAME == frodo ]] || timeout -s 9 5 ssh wrt.b8.nz :; then
  58     at_home=true
  59 fi
  60 echo "$0: at_home = $at_home"
  61
  62 source /a/bin/bash_unpublished/source-semi-priv
  63 #### begin convert private hostnames to public hostnames ####
  64 if ! $at_home; then
  65     for var in old_host new_host; do
  66         case ${!var} in
  67             treetowl)
  68                 eval $var=$HOME_DOMAIN
  69                 ;;
  70         esac
  71     done
  72 fi
  73 ####  end convert private hostnames to public hostnames ####
  74
  75
  76 # because our port forward is not robust enough, we can't use proxy command,
  77 # todo: setup vpn so this is all taken care of.
  78 if ! $at_home; then
  79     if [[ $old_host == iank.vpn.office.fsf.org || $new_host == iank.vpn.office.fsf.org ]]; then
  80         wrt_shell="ssh iank.vpn.office.fsf.org ssh wrt.b8.nz"
  81     else
  82         wrt_shell="ssh $HOME_DOMAIN ssh wrt.b8.nz"
  83     fi
  84 else
  85     wrt_shell="ssh wrt.b8.nz"
  86 fi
  87
  88 btrbk_test="systemctl is-active btrbk.service"
  89 while $new_shell $btrbk_test || $old_shell $btrbk_test; do
  90     echo "$0: btrbk is running on new or old host. sleeping for 8 seconds"
  91     sleep 6
  92     echo "$0: testing for btrbk activity in 2 seconds"
  93     sleep 2
  94 done
  95
  96 ########### end initial processing, begin actually modifying things ##########
  97
  98 restore_new_btrbk=false
  99 if $new_shell systemctl is-active btrbk.timer; then
 100     $new_shell sudo systemctl stop btrbk.timer
 101     restore_new_btrbk=true
 102 fi
 103 restore_old_btrbk=false
 104 if $old_shell systemctl is-active btrbk.timer; then
 105     $old_shell sudo systemctl stop btrbk.timer
 106     restore_old_btrbk=true
 107 fi
 108
 109 $new_shell bash -s <<'EOF'
 110 set -eE
 111 if mountpoint /m; then sudo umount /m; fi
 112 if mountpoint /o; then sudo umount /o; fi
 113 EOF
 114
 115 # if new_host is not on home network, make mail.iankelling.org not resolve
 116 # on the home network.
 117 if [[ $new_host == $HOSTNAME ]] && ! $at_home; then
 118     echo | $wrt_shell cedit mail_host /etc/hosts || [[ $? == 1 ]] # 1 means file changed.
 119 else
 120     $wrt_shell bash -s <<EOFOUTER
 121     cedit mail_host /etc/hosts <<EOF || /etc/init.d/dnsmasq restart
 122 \$(grep "\b$new_host\b" /etc/hosts | awk '{print \$1}') mail.iankelling.org
 123 EOF
 124 EOFOUTER
 125 fi
 126
 127 mail-setup() {
 128     shell="$1"
 129     $shell sed -ri "s/MAIL_HOST=.*/MAIL_HOST=$new_host/" /a/bin/bash_unpublished/source-semi-priv
 130     $shell /a/bin/distro-setup/mail-setup exim4
 131 }
 132
 133 mail-setup "$old_shell"
 134
 135 sudo dd of=/etc/btrbk.conf <<'EOF'
 136 ssh_identity /root/.ssh/id_rsa
 137 # Just a guess that local7 is a good facility to pick.
 138 # It's a bit odd that the transaction log has to be logged to
 139 # a file or syslog, while other output is sent to std out.
 140 # The man does not mention a way for them to be together, but
 141 # I dunno if setting a log level like warn might also output
 142 # transaction info.
 143 transaction_syslog local7
 144
 145 # so we only run one at a time
 146 lockfile                   /var/lock/btrbk.lock
 147
 148 # default format of short does not accomidate hourly preservation setting
 149 timestamp_format long-iso
 150
 151 # only make a snapshot if things have changed
 152 snapshot_create onchange
 153 # I could make this different from target_preserve,
 154 # if one disk had less space.
 155 # for now, keeping them equal.
 156 snapshot_preserve 36h 14d 8w 24m
 157 snapshot_preserve_min 4h
 158 snapshot_dir btrbk
 159
 160 # so, total backups = ~89
 161 target_preserve 36h 14d 8w 24m
 162 target_preserve_min 4h
 163
 164 # if something fails and it's not obvious, try doing
 165 # btrbk -l debug -v dryrun
 166
 167
 168 EOF
 169
 170
 171 if $localhost_new; then
 172     btrbk_src=ssh://$old_host/mnt/root
 173     btrbk_dst=/mnt/root/btrbk
 174 else
 175     btrbk_src=/mnt/root
 176     btrbk_dst=ssh://$new_host/mnt/root/btrbk
 177 fi
 178
 179 sudo tee -a /etc/btrbk.conf <<EOF
 180 volume $btrbk_src
 181 subvolume o
 182 target send-receive $btrbk_dst
 183 EOF
 184
 185
 186 sudo btrbk --progress run
 187 $new_shell mount-latest-subvol
 188
 189 mail-setup
 190
 191 if $restore_new_btrbk; then
 192     $new_shell sudo systemctl start btrbk.timer
 193 fi
 194 if $restore_old_btrbk; then
 195     $old_shell sudo systemctl start btrbk.timer
 196 fi