backup-restic.sh - My generap-purpose script to backup a system, balancing simplicity with configurability.

backup-restic.sample.conf

# This is an example file, with example values.

#export RESTIC_PASSWORD=apassword
#export RESTIC_REPOSITORY=b2:bucket:path
#export B2_ACCOUNT_ID=12345
#export B2_ACCOUNT_KEY=abcdefg

#restic_backup /etc
#restic_backup /root
#restic_backup /var
#restic_backup /usr/local
#restic_backup /home
#restic_backup --exclude /srv/Apt/acng/ /srv
#cd /tmp ; sudo -u postgres /usr/bin/pg_dumpall | restic_backup --stdin --stdin-filename postgres.sql


## Example of using LVM snapshots to backup point-in-time. This may be merged into backup-restic.sh
#snap_and_mount() {
#  if [ -z "$1" ] ; then return 1 ; fi
#  vg="$1"
#  if [ -z "$2" ] ; then return 1 ; fi
#  lv="$2"
#  size=${3:-200G}
#  /sbin/lvcreate --snapshot "$vg"/"$lv" --size $size --name backupsnapb2 --addtag temporary ; ret=$?
#  #echo "lvcreate $ret"
#  if [ $ret -eq 0 ] ; then
#    mkdir -p /mnt/VG-"$vg"_LV-"$lv"
#    mount -o ro /dev/"$vg"/backupsnapb2 /mnt/VG-"$vg"_LV-"$lv" ; ret=$?
#    #echo "mount $ret"
#  fi
#  # Returns the last exit value, either lvcreate or mount, which should be 0 if success
#  return $ret
#}
#umount_and_unsnap() {
#  if [ -z "$1" ] ; then return 1 ; fi
#  vg="$1"
#  umount /dev/"$vg"/backupsnapb2 ; ret=$?
#  #echo "Umount $ret"
#  if [ $ret -eq 0 ] ; then
#    /sbin/lvremove --force /dev/"$vg"/backupsnapb2 ; ret=$?
#    #echo "lvremove $ret"
#  fi
#  # Returns the last exit value, either lvcreate or mount, which should be 0 if success
#  return $ret
#}

## N=boot
#restic_backup /boot

#V=nextcloud-vg
#N=root
#if snap_and_mount $V $N 8G ; then
#  restic_backup /mnt/VG-"$V"_LV-"$N"/etc
#  restic_backup /mnt/VG-"$V"_LV-"$N"/home
#  umount_and_unsnap $V
#fi

backup-restic.sh

#!/usr/bin/env bash
# backup-restic
#
# Simple, basic script for performing backups using restic, and maintaining
# restic repositories.
# Configuration, including RESTIC_* and backend variables, and backup tasks go
# into /etc/backup-restic.conf which is a regular shell script that is sourced.
#
# Help: backup-restic.sh [configuration] [<help|install <version>|init|newkey|backup|$othercommands>]
#       configuration -- Optional path to a configuration file. Defaults to /etc/backup-restic.conf
#       install <version> -- install the specified version of restic to /usr/local/bin/restic
#       init -- Initialise a new repository (RESTIC_REPOSITORY in the configuration)
#       newkey -- Add a new key to the RESTIC_REPOSITORY
#       backup -- Backup the given path. This is an alias to the restic_backup directive.
#       $othercommands -- Any other restic commands, and their arguments, to be executed within the configured Restic parameters.
#       No Arguments -- Perform the default backup operation.
# 
# Installation: Install this script into /usr/local/bin/backup-restic.sh, then
#   write the configuration file with commands and restic_backup.
# Cron: /usr/bin/ionice -c 2 -n 4 /usr/bin/nice /usr/local/bin/backup-restic.sh /etc/backup-restic_b2.conf | /usr/bin/logger -t backup-restic_b2
#
# PS: Yes, it does require bash (or ksh) for `[[`
#
# Author: Bryce Chidester <bryce@cobryce.com>
# Copyright: BSD 2-clause
#
# Changelog:
# 4: Work-around for https://github.com/restic/restic/issues/1807 by not
#    passing --one-file-system if the backup command contains --stdin
# 3: Support for specifying/installing restic beta snapshots. Improved error
#    handling and resiliency, will now exit if there are any syntax errors.
#    Note: This may cause problems when restic reports an error (such as a file
#    having changed on-disk during backup). This will be addressed in the future.
#    Added support for PRUNE_OPTS?
# 2: Added some "help" functionality
# 1: Initial "release"

export SCRIPT_VERSION=4
UPSTREAM_VERSION=$(curl -sSL -A "$(basename $0)/$SCRIPT_VERSION ($(hostname))" https://brycesawesomeapp.com/backup-restic.sh | perl -n -e'/export SCRIPT_VERSION=(\d+)/ && print $1')
if [ "$UPSTREAM_VERSION" -gt "$SCRIPT_VERSION" ]; then
  echo "Warning: There is an updated script available. Upgrade with:"
  echo "curl --output $0 https://brycesawesomeapp.com/backup-restic.sh ; chmod +x $0"
  sleep 5
  # Don't exit, just warn.
fi

set -e # All errors (non-zero return) are fatal errors.
set -f # No globbing
set -C # No clobber

export CONFIG_FILE=/etc/backup-restic.conf
if [ -f "$1" ]; then
  echo "Found configuration file: $1"
  export CONFIG_FILE="$1"
  shift
fi
if [ ! -f "$CONFIG_FILE" ]; then
  echo "Unable to open the configuration file ($CONFIG_FILE). Exiting."
  exit 1
fi

export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
export SCRIPT_NAME=$(basename $0)
export SCRIPT_BASENAME=$(basename $0 .sh)
export CONFIG_NAME=$(basename $CONFIG_FILE)
export CONFIG_BASENAME=$(basename $CONFIG_FILE .conf)

function restic_backup { # Alias
  # Only runs once everything is ready and configured.
  [ "x$CONFIGURED" = "x1" ] || return 0
  ex=
  if ! [[ $@ == *'--stdin'* ]]; then
    ex=--one-file-system
  fi
  restic backup \
    --tag "SCR:$SCRIPT_NAME" \
    --tag "VER:$SCRIPT_VERSION" \
    --tag "CFG:$CONFIG_NAME" \
    $ex \
    $@
}

# Read the configuration (embedded calls to restic_backup will fail until CONFIGURED=1)
export CONFIGURED=0
. $CONFIG_FILE

if [[ "$1" = *help* ]]; then
  head -n22 $0
  exit 0

elif [ "x$1" = "xinstall" -a -n "$2" ]; then
  GOOS=$(uname -s)
  if [ "$GOOS" = "Linux" ]; then GOOS=linux
  elif [ "$GOOS" = "OpenBSD" ]; then GOOS=openbsd
  fi
  GOARCH=$(uname -m)
  if [ "$GOARCH" = "x86_64" ]; then GOARCH=amd64
  elif [[ "$GOARCH" = i*86 ]]; then GOARCH=386
  fi
  if [[ "$2" = *.*.*-* ]]; then
    echo "Downloading and installing restic SNAPSHOT v$2 for $GOOS/$GOARCH"
    if ! curl -sSL --output /usr/local/bin/restic https://beta.restic.net/v$2/restic_v${2}_${GOOS}_${GOARCH} ; then
      echo "Error downloading restic."
      exit 1
    fi
  else
    echo "Downloading and installing restic v$2 for $GOOS/$GOARCH"
    # Note: curl exits non-zero if bzcat fails because curl "Failed writing body"
    if ! curl -sSL https://github.com/restic/restic/releases/download/v$2/restic_${2}_${GOOS}_${GOARCH}.bz2 | bzcat > /usr/local/bin/restic ; then
      echo "Error downloading restic."
      exit 1
    fi
  fi
  chmod +x /usr/local/bin/restic
  exit 0

elif [ "x$1" = "xinstall" ]; then
  echo "A version to install must be specified."
  exit 1

elif [ "x$1" = "xnewkey" ]; then
  echo -n "Enter current password: "
  read -s RESTIC_PASSWORD
  echo
  restic key add
  echo Be sure to update RESTIC_PASSWORD
  exit 0

elif [ "x$1" = "xinit" ]; then
  restic init -o b2.connections=10
  exit 0

elif [ -n "$1" ]; then
  if [ "$1" = "backup" ]; then
    shift
    export CONFIGURED=1
    restic_backup $@
  else
    restic $@
  fi
  exit 0

fi

# TODO: Change lock path on OpenBSD
if ! mkdir /var/lock/$SCRIPT_BASENAME ; then echo Lock file exists. Another backup process is already running. ; exit 1 ; fi
trap "rmdir /var/lock/$SCRIPT_BASENAME" EXIT INT TERM ERR

# No point scooping up anything temporary
which apt-get 2>/dev/null >/dev/null && apt-get clean

# This time, it's okay to run
export CONFIGURED=1
. $CONFIG_FILE