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