borg-remote-android/backup-android.sh

#!/data/data/com.termux/files/usr/bin/bash
# Initialize
# if [ -z "$STY" ]; then exec screen -m -S backup-android /bin/bash "$0"; fi
ABSPATH="$(readlink -f "$BASH_SOURCE")"
set -x
cd "${ABSPATH%/*}" || { echo "Cannot change directory" >&2; exit 1; }
test -f ./env && source ./env || { echo "Unable to source user variables in $PWD"; exit 1;  }

# From https://serverfault.com/a/799198
# Since Termux has no uuidgen command, we need to create one randomly
function uuidgen() {
	od -x /dev/urandom | head -1 | awk '{OFS="-"; print $2$3,$4,$5,$6,$7$8$9}'
}

# From https://unix.stackexchange.com/a/27014
function time_diff {
	# Find the time difference between the two arguments (in seconds)
	local T="$(( "$1" - "$2" ))"
	local D=$((T/60/60/24))
	local H=$((T/60/60%24))
	local M=$((T/60%60))
	local S=$((T%60))
	(( $D > 0 )) && printf '%dd ' $D
	(( $H > 0 )) && printf '%dh ' $H
	(( $M > 0 )) && printf '%dm ' $M
	(( $D > 0 || $H > 0 || $M > 0 )) && printf 'and '
	printf '%ds\n' $S
}

function prune() {
	if [ -z "$PRUNE_COMMAND" ]; then
		echo "Not pruning" >&2
		return
	fi
	run_remote "${PRUNE_COMMAND[@]}" "$BORG_REPO"
}
function backup() {
	# First, we need to rsync our changes to the host
	echo "Running rsync..."
	local RETRIES=10
	while (( RETRIES > 0 )); do
		# Try to rsync
		"${RSYNC_COMMAND[@]}" "$SOURCE_LOCATION" "$REMOTE_HOST:$DESTINATION_LOCATION" && break
		(( RETRIES-- ))
		echo "rsync failed. Retrying $RETRIES more times. Sleeping 10s"
		sleep 10s
	done

	if (( RETRIES == 0 )); then
		# We exceeded the retry limit. Fail
		return 1
	fi

	# Next, instruct the host to create a borg
	echo "Running borg..."
	run_remote "${CREATE_COMMAND[@]}" "$BORG_REPO::$HOSTNAME-$(uuidgen)" . || return 2
}

# Take wakelock so we don't fall asleep
termux-wake-lock
START_TIME="$(date +%s)"

# Perform the backup
backup
RESULT=$?
DURATION="$(time_diff "$(date +%s)" "$START_TIME" )"

# Prune
prune

echo "Completed $(date +%F-%T)"
echo "Duration: $DURATION"

if (( RESULT == 0 )); then
	termux-notification --title "Backup completed successfully in $DURATION"
else
	termux-notification --title "Backup failed in $DURATION"
fi

# Remove our wakelock
termux-wake-unlock
printf "^c to exit"
cat