bkp-prune.sh

#! /usr/bin/env bash

set -e

command -v restic >/dev/null 2>&1 || { echo >&2 "Required command restic is not installed."; exit 1; }
command -v zstd >/dev/null 2>&1 || { echo >&2 "Required command zstd is not installed."; exit 1; }

SCRIPT_DIR="$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
if command -v "bkp-env.sh" >/dev/null 2>&1 ; then
    CMD_BKP_ENV="bkp-env.sh"
elif command -v "${SCRIPT_DIR}/bkp-env.sh" >/dev/null 2>&1 ; then
    CMD_BKP_ENV="${SCRIPT_DIR}/bkp-env.sh"
fi
if [ -z ${CMD_BKP_ENV+x} ]; then
    echo "Can not find bkp-env.sh"
    exit 3
fi
. $CMD_BKP_ENV --no-auto
bkp_load_env bkp-prune

if [ -z ${BKP_RESTIC_PASSWORD+x} ]; then
    echo "BKP_RESTIC_PASSWORD is unset"
    exit 3
fi
if [ -z ${BKP_REAL_PATH_RESTIC_REPOSITORY+x} ]; then
    echo "Repository folder $BKP_REAL_PATH_RESTIC_REPOSITORY is unset"
    exit 3
fi
if [ ! -d "${BKP_REAL_PATH_RESTIC_REPOSITORY}" ]; then
    echo "Repository folder $BKP_REAL_PATH_RESTIC_REPOSITORY is not present"
    exit 2
fi
export RESTIC_PASSWORD="${BKP_RESTIC_PASSWORD}"
log="$HOME/bkp-prune-$(date +%Y%m%d_%H%M%S).log.zst"
echo "LOG: $log"

processRepoClean() {
    restic unlock \
      -r "$1" \
      2>&1 | tee >(zstd -T0 --long >> "$log")

    # keep daily snapshots for a week, weekly for a month, monthly for a year and yearly for 2 years:
    ionice -c 2 -n 7 nice -n 19 \
    restic forget --verbose \
      --cleanup-cache \
      -r "$1" \
      --group-by host,tags \
      --keep-within-daily 7d --keep-within-weekly 1m --keep-within-monthly 1y --keep-within-yearly 2y \
      --keep-last 7 \
      2>&1 | tee >(zstd -T0 --long >> "$log")

    ionice -c 2 -n 7 nice -n 19 \
    restic prune --max-unused 0 \
      -r "$1" \
      2>&1 | tee >(zstd -T0 --long >> "$log")

    ionice -c 2 -n 7 nice -n 19 \
    restic check --read-data-subset=9.9% \
      -r "$1" \
      2>&1 | tee >(zstd -T0 --long >> "$log")
}

processRepoKeepOneClean() {
    restic unlock \
      -r "$1" \
      2>&1 | tee >(zstd -T0 --long >> "$log")

    ionice -c 2 -n 7 nice -n 19 \
    restic forget --keep-last 1 \
      -r "$1" \
      2>&1 | tee >(zstd -T0 --long >> "$log")

    ionice -c 2 -n 7 nice -n 19 \
    restic prune --max-unused 0 \
      -r "$1" \
      2>&1 | tee >(zstd -T0 --long >> "$log")
}

find "$BKP_REAL_PATH_RESTIC_REPOSITORY" -mindepth 0 -maxdepth 3 -name 'snapshots' -type d | \
while read k ; do
    dir="$(dirname $k)"
    if [ -r "${dir}/config" ] ; then
        echo "${dir}"
    fi
done | \
while read repo ; do
    processRepoClean "$repo"
    #processRepoKeepOneClean "$repo"
done