#!/bin/sh
# tadaen sylvermane | jason gibson
# duplicity script to backup all users on given machine via hostname
# script meant to be run from a single location over nfs share. it has a
# local and server part differentiated by hostname variable. requires
# root ssh via key.

# tested in virtualbox with a source and target vm.

# variables #

SERVER=192.168.1.83
SERVERHN=testserver
SERVERBUPATH=/snapraid/pool/backups/homebackups
SSHFSMOUNT=/tmp/"$SERVERHN"backuptemp

# begin script #

if [ "$SERVERHN" != $(uname -n) ] ; then
	case "$1" in
		backups)
			if [ "$USER" = root ] ; then
				# users to be backed up #
				for user in /home/* ; do
					BUSER=$(basename "$user")
					BACKUPLAUNCHER=/home/"$BUSER"/.local/share/applications/org.gnome.DejaDup.desktop
					# adjust backups launcher to run script instead of program directly
					# does by copying the .desktop file to the given users 
					# ~/.local/share/applications and adjusting to run this script instead
					# of the program directly. script edits target information into
					# deja dup via gsettings.
					if [ ! -f "$BACKUPLAUNCHER" ] ; then
						mkdir -p $(dirname "$BACKUPLAUNCHER")
						cp /usr/share/applications/org.gnome.DejaDup.desktop \
						"$BACKUPLAUNCHER"
						chown -R "$BUSER":"$BUSER" /home/"$BUSER"
						sed -i "s|Exec=deja-dup|Exec=${0} restore|" "$BACKUPLAUNCHER"
					fi
					# prep for each user and hostname. this will create backup 
					# folders as needed.
					[ -d "$SSHFSMOUNT" ] || mkdir -p "$SSHFSMOUNT"
					if ping -c 1 "$SERVER" ; then
						# runs on backup server making sure the target directory exists.
						ssh root@"$SERVER" "newbackups.sh create"
						sshfs root@"$SERVER":/"$SERVERBUPATH" "$SSHFSMOUNT"
						# sanity check for mountpoint
						if ! mountpoint -q "$SSHFSMOUNT" ; then
							echo "failed mount! exiting!"
							exit 1
						fi
					fi
					# temp directory creation for sshfs mounting
					[ -d "$SSHFSMOUNT"/$(uname -n)/"$BUSER" ] \
					|| mkdir -p "$SSHFSMOUNT"/$(uname -n)/"$BUSER"
					# basics. this is what i use around here. would be a bit more involved
					# if encryption required.
					duplicity \
						--exclude-if-present .nobackup \
						--no-encryption \
						--full-if-older-than 1M \
						/home/"$BUSER" file://"$SSHFSMOUNT"/$(uname -n)/"$BUSER"
					wait
					# basics for me again. clean up over time.
					duplicity remove-all-but-n-full 4 --force \
						file://"$SSHFSMOUNT"/$(uname -n)/"$BUSER"
					wait
					# unmount sshfs
					umount "$SSHFSMOUNT"
					# run this function on the backup server setting the rwx as needed
					# so users can read but can't delete or modify their existing backups
					ssh root@"$SERVER" "newbackups.sh permissions"
				done
			fi
			;;
		restore)
			# enters settings into deja dup gui for restoration. the users will need
			# ssh access to the backup server. keys preferrable but can be done with
			# name + password. This runs when the Backups / Deja Dup tool is called.
			# if anythign changes you just change it here in the variables. as the
			# script should be located on a central point (nfs share in my case) if I
			# update it then it's automatically updated everywhere it's shared to.
			gsettings set org.gnome.DejaDup.Remote uri \
			"ssh://${SERVER}"
			gsettings set org.gnome.DejaDup.Remote folder \
			"${SERVERBUPATH}/$(uname -n)/${USER}"
			deja-dup
			;;
	esac
else
	case "$1" in
		create)
			# will create backup path in variable if not exist
			[ -d "$SERVERBUPATH" ] || mkdir -p "$SERVERBUPATH"
			;;
		permissions)
			# this will be run on the backup server. makes sure people can restore
			# their backups while they are owned by root. also they cannot delete
			# the backups themselves.
			find "$SERVERBUPATH"/ \
				-mindepth 2 \
				-type d \
				-exec chmod 755 {} \;
			find "$SERVERBUPATH"/ \
				-mindepth 2 \
				-type f \
				-exec chmod 644 {} \;
			;;
	esac
fi

# end script #