restic_backup.sh

#!/bin/bash
# This script backs up files using restic and sends emails on success or errors.
#
# Files that the script expects:
#   /usr/local/etc/restic/repo.env: shell variables that define the restic repository
#   /usr/local/etc/restic/include.txt: paths to back up
#   /usr/local/etc/restic/exclude.txt: paths to not include in the backup, even if they are in include.txt
#
# Inspired by https://gist.github.com/perfecto25/18abbd6cfbaa4e9eb30251470e9b7504

FROM="restic@homeserver"
TO="you@example.com"
EMAIL_SUBJECT_PREFIX="[Restic] "
LOG="/var/log/restic/$(date +\%Y\%m\%d_\%H\%M\%S).log"

EXCLUDE="/usr/local/etc/restic/exclude.txt"
INCLUDE="/usr/local/etc/restic/include.txt"

notify() {
        cat "${LOG}" | mail -r "${FROM}" -s "${EMAIL_SUBJECT_PREFIX}${1}" "${TO}"
}

source /usr/local/etc/restic/repo.env

# backup
echo -e "restic backup\n------------\n" >> "$LOG"
restic backup --exclude-file="$EXCLUDE" --files-from="$INCLUDE" >> "$LOG" 2>&1
if [ $? -ne 0 ]
then
        notify "backup error"
        exit 2
fi

# check consistency of the repository
echo -e "\n------------\nrestic check\n-----------\n" >> "$LOG"
restic check >> "$LOG" 2>&1
if [ $? -ne 0 ]
then
        notify "check error"
        exit 3
fi

# remove outdated snapshots
echo -e "\n-------------\nrestic forget\n------------\n" >> "$LOG"
restic forget \
       --keep-daily 7 \
       --keep-weekly 4 \
       --keep-monthly 3 \
       --keep-yearly 3 \
       >> "$LOG" 2>&1
if [ $? -ne 0 ]
then
        notify "forget error"
        exit 4
fi

# prune once a month
day=$(date +%d)
if [[ $day =~ 0[1-7] ]]
then
        echo -e "\n------------\nrestic prune\n-----------\n" >> "$LOG"
        restic prune >> "$LOG" 2>&1
        if [ $? -ne 0 ]
        then
                notify "prune error"
                exit 5
        fi
fi

notify "success"