Backup script for restic

backup_restic.sh

#!/usr/bin/env bash
# shellcheck disable=SC2128
SOURCED=false && [ "$0" = "$BASH_SOURCE" ] || SOURCED=true

if ! $SOURCED; then
  set -euo pipefail
  IFS=$'\n\t'
fi

awk_script=$(cat <<'AWKSCRIPT'
BEGIN   { RS="(\r|\n)";
          FS="";
        }
{
    printf "[" strftime("%Y-%m-%d %H:%M:%S") "]: ";
    printf $0;
    if (RT=="\r") {
        printf "\r";
    } else {
        printf "\n";
    }
}
AWKSCRIPT
)
OLDIFS="$IFS"
IFS='' awk_script=$(echo "$awk_script" | tr '\t' ' ' | tr '\n' ' ')
IFS="$OLDIFS"

LOGFILE='/var/log/backup/restic.log'

#################### functions
function log() {

  echo "$1" | awk '{print "[" strftime("%Y-%m-%d %H:%M:%S") "]: " $0 }' | \
    sudo tee -a "$LOGFILE"

  return 0
}
##############################################################################

log 'Start'

# shellcheck disable=SC1090
source "$HOME/.restic/environment"

if [ -z "$RESTIC_REPOSITORY" ] || [ -z "$RESTIC_PASSWORD_FILE" ]; then
  (>&2 echo 'RESTIC_REPOSITORY or RESTIC_PASSWORD_FILE not set. Abort.' )
  exit 1
fi

if [ ! -d "$RESTIC_REPOSITORY" ]; then
  (>&2 echo 'RESTIC_REPOSITORY is not a directory. Abort.' )
  exit 2
fi

sudo mkdir -p '/var/log/backup/'
sudo touch "$LOGFILE"

log 'Backing up...'

sudo -EH stdbuf -o0 restic backup \
                            --exclude-file "$RESTIC_EXCLUDES_FILE" \
                            "$RESTIC_BACKUP_TARGET" 2>&1 | \
          stdbuf -o0 awk "$awk_script" | \
          sudo tee -a "$LOGFILE"

log 'Backup complete'

exit 0