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 -w         Don't try to ssh to wrt. Should only be used in unusual network situation.
  15 -h|--help  Print help and exit.
  16
  17 Note: Uses GNU getopt options parsing style
  18 EOF
  19     exit $1
  20 }
  21
  22 ##### begin command line parsing ########
  23
  24 update_wrt=true # default
  25 long_opt=foo # default
  26 temp=$(getopt -l help wh "$@") || usage 1
  27 eval set -- "$temp"
  28 while true; do
  29     case $1 in
  30         -w) update_wrt=false; shift ;;
  31         -h|--help) usage ;;
  32         --) shift; break ;;
  33         *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  34     esac
  35 done
  36
  37
  38 (( $# == 2 )) || usage 1
  39
  40 old_host=$1
  41 new_host=$2
  42 source /a/bin/bash_unpublished/source-semi-priv
  43
  44 if [[ $old_host != $MAIL_HOST ]]; then
  45     read -p "warning: \$old_host != \$MAIL_HOST: $old_host != $MAIL_HOST, proceed? y/N "
  46     if [[ $REPLY != [yY] ]]; then
  47         exit 1
  48     fi
  49 fi
  50
  51 if [[ $new_host == "$HOSTNAME" ]]; then
  52     localhost_new=true
  53     new_shell=
  54 else
  55     localhost_new=false
  56     new_shell="ssh $new_host"
  57 fi
  58
  59 old_shell="ssh $old_host"
  60 if [[ $old_host == "$HOSTNAME" ]]; then
  61     old_shell=
  62 fi
  63
  64 if [[ ! $new_host || ! $old_host ]]; then
  65     echo "$0: bad args. see script"
  66     exit 1
  67 fi
  68
  69 at_home=false
  70 if [[ $HOSTNAME == tp ]] || [[ $HOSTNAME == frodo ]] || timeout -s 9 5 ssh wrt.b8.nz :; then
  71     at_home=true
  72 fi
  73 echo "$0: at_home = $at_home"
  74
  75 source /a/bin/bash_unpublished/source-semi-priv
  76 #### begin convert private hostnames to public hostnames ####
  77 if ! $at_home; then
  78     for var in old_host new_host; do
  79         case ${!var} in
  80             tp)
  81                 eval $var=$HOME_DOMAIN
  82                 ;;
  83         esac
  84     done
  85 fi
  86 ####  end convert private hostnames to public hostnames ####
  87
  88
  89 # because our port forward is not robust enough, we can't use proxy command,
  90 # todo: setup vpn so this is all taken care of.
  91 if ! $update_wrt; then
  92     wrt_shell=:
  93 elif $at_home; then
  94     wrt_shell="ssh wrt.b8.nz"
  95 else
  96     if [[ $old_host == iank.vpn.office.fsf.org || $new_host == iank.vpn.office.fsf.org ]]; then
  97         wrt_shell="ssh iank.vpn.office.fsf.org ssh wrt.b8.nz"
  98     else
  99         wrt_shell="ssh $HOME_DOMAIN ssh wrt.b8.nz"
 100     fi
 101 fi
 102
 103 btrbk_test="systemctl is-active btrbk.service"
 104 while $new_shell $btrbk_test || $old_shell $btrbk_test; do
 105     echo "$0: btrbk is running on new or old host. sleeping for 8 seconds"
 106     sleep 6
 107     echo "$0: testing for btrbk activity in 2 seconds"
 108     sleep 2
 109 done
 110
 111 ########### end initial processing, begin actually modifying things ##########
 112
 113 restore_new_btrbk=false
 114 if $new_shell systemctl is-active btrbk.timer; then
 115     $new_shell sudo systemctl stop btrbk.timer
 116     restore_new_btrbk=true
 117 fi
 118 restore_old_btrbk=false
 119 if $old_shell systemctl is-active btrbk.timer; then
 120     $old_shell sudo systemctl stop btrbk.timer
 121     restore_old_btrbk=true
 122 fi
 123
 124 $new_shell bash -s <<'EOF'
 125 set -eE
 126 if mountpoint /m; then sudo umount /m; fi
 127 if mountpoint /o; then sudo umount /o; fi
 128 EOF
 129
 130 # if new_host is not on home network, make mail.iankelling.org not resolve
 131 # on the home network.
 132 if [[ $new_host == $HOSTNAME ]] && ! $at_home; then
 133     echo | $wrt_shell cedit mail_host /etc/hosts || [[ $? == 1 ]] # 1 means file changed.
 134 else
 135     $wrt_shell bash -s <<EOFOUTER
 136     cedit mail_host /etc/hosts <<EOF || /etc/init.d/dnsmasq restart
 137 \$(grep "\b$new_host\b" /etc/hosts | awk '{print \$1}') mail.iankelling.org
 138 EOF
 139 EOFOUTER
 140 fi
 141
 142 mail-setup() {
 143     shell="$1"
 144     $shell sed -ri "s/MAIL_HOST=.*/MAIL_HOST=$new_host/" /a/bin/bash_unpublished/source-semi-priv
 145     $shell /a/bin/distro-setup/mail-setup exim4
 146 }
 147
 148 mail-setup "$old_shell"
 149
 150 sudo dd of=/etc/btrbk.conf <<'EOF'
 151 ssh_identity /root/.ssh/id_rsa
 152 # Just a guess that local7 is a good facility to pick.
 153 # It's a bit odd that the transaction log has to be logged to
 154 # a file or syslog, while other output is sent to std out.
 155 # The man does not mention a way for them to be together, but
 156 # I dunno if setting a log level like warn might also output
 157 # transaction info.
 158 transaction_syslog local7
 159
 160 # so we only run one at a time
 161 lockfile                   /var/lock/btrbk.lock
 162
 163 # default format of short does not accomidate hourly preservation setting
 164 timestamp_format long-iso
 165
 166 # only make a snapshot if things have changed
 167 snapshot_create onchange
 168 # I could make this different from target_preserve,
 169 # if one disk had less space.
 170 # for now, keeping them equal.
 171 snapshot_preserve 36h 14d 8w 24m
 172 snapshot_preserve_min 4h
 173 snapshot_dir btrbk
 174
 175 # so, total backups = ~89
 176 target_preserve 36h 14d 8w 24m
 177 target_preserve_min 4h
 178
 179 # if something fails and it's not obvious, try doing
 180 # btrbk -l debug -v dryrun
 181
 182
 183 EOF
 184
 185
 186 if $localhost_new; then
 187     btrbk_src=ssh://$old_host/mnt/root
 188     btrbk_dst=/mnt/root/btrbk
 189 else
 190     btrbk_src=/mnt/root
 191     btrbk_dst=ssh://$new_host/mnt/root/btrbk
 192 fi
 193
 194 sudo tee -a /etc/btrbk.conf <<EOF
 195 volume $btrbk_src
 196 subvolume o
 197 target send-receive $btrbk_dst
 198 EOF
 199
 200
 201 sudo btrbk --progress run
 202 $new_shell mount-latest-subvol
 203
 204 mail-setup
 205
 206 if $restore_new_btrbk; then
 207     $new_shell sudo systemctl start btrbk.timer
 208 fi
 209 if $restore_old_btrbk; then
 210     $old_shell sudo systemctl start btrbk.timer
 211 fi