#!/bin/bash

# Cronjob needs to be on one line, spaced out for example/ in-case running cronjob from a script that just runs the below
# e.g. 0 0 * * * /home/nathan/scripts/backup/borg/docker_backup.sh \
# -c "duckdns homer" \
# -d /home/samba/share/Docker_prod \
# -b /home/nathan/testBack \
# -r pi2 \
# -R ~/backups/pi1/docker

# Flags
while getopts c:d:b:r:R: flag
do
	case "${flag}" in
	    c) CONTAINER_DIRS=${OPTARG};; # Will accept an 'array', just individual names spaced within quotes. i.e. "homer npm vaultwarden"
		d) DIR=${OPTARG};; # /home/nathan/docker typically
	    b) BACKUP_DIR=${OPTARG};; # Where the backup is on local host
	    r) REMOTE=${OPTARG};; # user@remote or alias (from SSH config), prefer to use alias, as it can deal with port differences
	    R) REMOTE_DIR=${OPTARG};; # Location of remote backup i.e. /backup/borg/HOSTNAME/docker (then /npm, /vaultwarden, etc.)
	esac
done

# Borg assistance: https://borgbackup.readthedocs.io/en/stable/quickstart.html
# export BORG_PASSPHRASE='' # If using encryption in borg, ignoring for now, to just have it work

# Will need permissions to read and enter directories
# sudo setfacl -Rdm "u:nathan:rX" /home/samba/share/Docker_prod && sudo setfacl -Rm "u:nathan:rX" /home/samba/share/Docker_prod
# Also need to be part of docker group to down/up: sudo groupadd docker && sudo usermod -aG docker nathan

# Function(s)
borg_backup (){
	# $1 is the first variable passed to the function
	if [ ! -d "$1" ]; then
		mkdir -p $1
		borg init --encryption=none $1
	fi

	export BORG_REPO=$1
	borg create ::{hostname}-{now} $DIR/$i
}
borg_prune () {
	# Keep last 8 hours of backups, last 3 days, and last 2 weeks. LESS for local to save storage
	borg prune						\
	--glob-archives	'{hostname}-*'	\
    --keep-daily	5				\
    --keep-weekly	2
	# Then compact (actually clear up the disk space of the files removed via prune)
	borg compact
}
offsite_borg () {
	export BORG_REPO=$REMOTE:$1 # $1 is the first variable passed to the function
	borg create ::{hostname}-{now} $DIR/$i # Backup with of the directory itself (seperate borg repo)
}
offsite_prune () {
	export BORG_REPO=$REMOTE:$1 # $1 is the first variable passed to the function
	# Prune on server, this may take ages though so I'm not sure about this...
	borg prune						\
	--glob-archives	'{hostname}-*'	\
    --keep-daily	7				\
    --keep-weekly	4				\
    --keep-monthly	6				\
	--keep-yearly	1
	# Then compact (actually clear up the disk space of the files removed via prune)
	borg compact
}

# Script
DIRS=($CONTAINER_DIRS) # Put the CONTAINER_DIRS passed into an array that can be looped # DIRS=(homer npm) to hardcode
#DIRS=( "$DOCKER"/*/ )

# Currently backs up each docker container in its own repo, may be more efficient to have
# them all in the same repo? But this makes sense to me in a backup directory
for i in "${DIRS[@]}"
do

	# Stop docker containers before backup incase any moving parts
	cd $DIR/$i # Change into the container's directory (so it can be up/downed)
	docker compose stop

	# Local
	# Backup the container
	borg_backup "$BACKUP_DIR/$i"

	# Offsite
	# Check if the directory/repo exists. Create if not, and backup
	if (ssh $REMOTE ls $REMOTE_DIR/$i  2>/dev/null);
	then
		offsite_borg "$REMOTE_DIR/$i"
	else
		# Doesn't exist, create, and init repo first
		ssh $REMOTE mkdir -p $REMOTE_DIR/$i
		borg init --encryption=none $REMOTE:$REMOTE_DIR/$i
		offsite_borg "$REMOTE_DIR/$i"
	fi

	# Bring the container back up
	docker compose start

done

# To prevent hangs and the container(s) being down too long
# the prune occurs after all the containers are backed-up, and running/started
for i in "${DIRS[@]}"
do
	borg_prune "$REMOTE_DIR/$i"
	offsite_prune "$REMOTE_DIR/$i"
done