backup

#!/usr/bin/env bash

set -o errexit   # Exit on most errors
set -o nounset   # Dissallow expansion of unset variables

DISK=/media/backup
export BORG_PASSPHRASE="$(pass borg)"
BORG_REPOSITORY="$DISK/borg"

# DESC: notify the user that backups are done
# ARGS: none
function notify() {
  BORG_PUSHOVER_USER="$(pass borg-pushover-user)"
  BORG_PUSHOVER_TOKEN="$(pass borg-pushover-token)"
  # Pushover app
  curl -s \
    --form-string "token=$BORG_PUSHOVER_TOKEN" \
    --form-string "user=$BORG_PUSHOVER_USER" \
    --form-string "message=Your backups are completed" \
    https://api.pushover.net/1/messages.json

  zenity --info --text='Backup complete!'
}

# DESC: Unmount the given disk
# ARGS: Disk to unmount
function unmount() {
  devmon --unmount "$1"
}

# DESC: prune the archive to reduce consumed disk space
# ARGS: location of archive
function prune_backup_archive() {
  # Use the `prune` subcommand to maintain 7 daily, 4 weekly and 6 monthly
  # archives of THIS machine. The '{hostname}-' prefix is very important to
  # limit prune's operation to this machine's archives and not apply to
  # other machine's archives also.
  borg prune -v "$1" --prefix '{hostname}-' \
    --keep-daily=7 --keep-weekly=4 --keep-monthly=6 &>>"$HOME/backup.log"
}

# DESC: make new backup archive for the day
# ARGS: location of backup repository
function create_backup_archive() {
  # Backup all of $HOME except a few excluded directories
  borg create --verbose --stats --progress      \
    --compression lzma,9                        \
    "$1"::'{hostname}-{now:%Y-%m-%d}'  \
    "$HOME"                                     \
    --exclude "$HOME/code"                      \
    --exclude "$HOME/.cache"                    \
    --exclude "$HOME/Dropbox"                   \
    --exclude "$HOME/.rustup"                   \
    --exclude "$HOME/.cargo"                    \
    --exclude "$HOME/backup.log"                \
    --exclude '*tags'                           \
    --exclude '*.pyc'                           \
    --exclude '*.class'                         \
    --exclude '*.com'                           \
    --exclude '*.dll'                           \
    --exclude '*.exe'                           \
    --exclude '*.o'                             \
    --exclude '*.so'                            \
    --exclude '*.beam'                          \
    --exclude-caches                            \
    --exclude-if-present '.git' &>>"$HOME/backup.log"
}

create_backup_archive "$BORG_REPOSITORY"
prune_backup_archive "$BORG_REPOSITORY"
unmount "$DISK" && notify