scripts/borg_wrap.sh

#!/bin/sh
##### This is my (demuredemeanor) borgbackup wrapper script.
# Blog Post: https://demu.red/blog/2017/02/backups-revisited/
# Source Code:  https://notabug.org/demure/scripts/src/master/borg_wrap.sh
# Uses tabstop=4; shiftwidth=4 tabs; foldmarker={{{,}}};
#
# This is a script to run my borg backups.
# It has basic config error checking, and verifies I am on my home network.
# Usage: borg_wrap.sh [-q|--quiet]
#
# Note: I run this as root, and have a /etc/sudoers.d/ file granting permissions.
#
# Note: I run this via crontab
# 0 */1 * * * sudo /usr/local/sbin/borg_wrap.sh -q
#
# Note: pruning:
# borg prune -v --list --dry-run -d=7 -w=4 -m=12 -y=-1 --keep-within=1d /media/store/backups/doom/

### Conf ### {{{
## Set Repo location
#export BORG_REPO='/media/store/backups/doom/'
export BORG_REPO='ssh://demure@10.0.0.10:500/mnt/borg/doom'

## Set the right ssh key
## Note, use with the following in the destination ssh authorized_keys
## command="borg serve --restrict-to-path /path/to/repo",no-pty,no-agent-forwarding,no-port-forwarding,no-X11-forwarding,no-user-rc ssh-rsa AAAAB3[...]
export BORG_RSH="ssh -i $HOME/.ssh/borg_id_ed25519"

## Pull Repo passwd
export BORG_PASSPHRASE="$(pass cli/borg 2>/dev/null)"

## Path to log file
Log_Path="$HOME/.config/borg/log"

## Temp file for log pruning
Log_tmp="/tmp/borg_log.tmp"

## Define home routers MAC addr.
MAC_addr="10:FE:ED:E9:63:04"

## Define remote address, for testing.
Host="10.0.0.10"
### End Conf ### }}}

### Conf Check ### {{{
## Exit if BORG_REPO not specified.
if [ "${BORG_REPO}" = "" ]; then
	echo 'No repo specified.'
	exit 78
fi

## Exit if no log file specified.
if [ "${Log_Path}" = "" ]; then
	echo 'No log file specified.'
	exit 78
fi

## Exit if no router MAC specified.
if [ "${MAC_addr}" = "" ]; then
	echo 'No router MAC specified.'
	exit 78
fi

## Exit if storage address specified.
if [ "${Host}" = "" ]; then
	echo 'No storage address specified.'
	exit 78
fi
### End Conf Check ### }}}

### Startup Check ### {{{
	### Augment Check ### {{{
	if [ $# -gt 1 ]; then
		echo 'Too many augments.'
		exit 1
	fi

	if [ ! -z "$1" ]; then
		if [ "$1" = '-q' ] || [ "$1" = '--Quiet' ]; then
			VERBOSE=""
			Quiet=1
		else
			echo 'Bad augments.'
			exit 1
		fi
	  else
		VERBOSE='-v --stats -p'
		Quiet=0
	fi
	### End Augment Check ### }}}

	### Network Check ### {{{
	check_mac="$(/bin/ip neigh | awk '/router/ {} END {print $5}')"
	if [ ! "$MAC_addr" = "$check_mac" ]; then
		if [ $Quiet -eq 0 ]; then
			echo "Not on home network."
		fi
		Error='BadNet'
	  else
		ping -c 3 $Host 1>/dev/null
		if [ ! $? = 0 ]; then
			if [ $Quiet -eq 0 ]; then
				echo "Can't reach host."
			fi
			Error='NoPing'
		fi
	fi
	### End Network Check ### }}}

	### Passwd Load Check ### {{{
	if [ -z "$BORG_PASSPHRASE" ]; then
		if [ $Quiet -eq 0 ]; then
			echo "Password failed to load."
		fi
		Error='NoPass'
	fi
	### End Passed Load Check ### }}}
### End Startup Check ### }}}

## If no errors, run.
if [ -z $Error ]; then
	borg create ${VERBOSE} -C lz4 \
				::'{hostname}_{now:%Y-%m-%d_%H%M}' \
				/ \
				--exclude-caches \
				-e /dev \
				-e /media/ \
				-e /mnt/ \
				-e /proc \
				-e /run \
				-e /sys \
				-e /tmp \
				-e /var/cache \
				-e '/var/tmp/*' \
				-e '/home/*/Downloads/' \
				-e '/home/*/temp/' \
				-e '/home/*/vault' \
				-e '/home/*/.config/chromium' \
				-e '/home/*/.local/share/mana/updates' \
				-e '*.cache' \
				-e '*.mail' \
				-e '*.thumbnails'

	## Catch exit code
	Error=$?
fi

## Log pass/fail state
if [ ! $Error = "0" ]; then
	echo "$(date '+%F %T')\tfailed\t${Error}" | cat >> ${Log_Path}
  else
	echo "$(date '+%F %T')\tpassed" | cat >> ${Log_Path}
fi

## This prunes the log, leaving last 30 days.
## If no passed backups in 30 days, also leaves lasted passed entry.
## You can comment out to disable
awk -v cutoff="$(date -d"-30 days" +%F)" 'BEGIN{pchk=0} {a[i++]=$0} END{for(j=i-1;j>=0;j--) if(a[j] >= cutoff || pchk==0 && a[j] ~ /passed/){if(a[j] ~ /passed/){pchk=1}; b[k++]=a[j]};{for(l=k-1;l>=0;l--) print b[l]}}' ${Log_Path} > ${Log_tmp} && mv ${Log_tmp} ${Log_Path}

## Fix borg permissions so that things like `borg list` work without sudo
## This assumes that sudo preserves envars.
chown -R ${USER}:${USER} ${HOME}/.config/borg ${HOME}/.cache/borg