backup.sh

#!/usr/bin/env bash

# This script will 
#	1. (Optionally) First snapshot your BTRFS /home subvolume as /resticbackup
#	2. Generate a list of packages and backup as `pkglist'
#	3. Backup the pacman cache directory
#	4. Backup the users home directory (from the BTRFS snapshot or directly)

# Try to load a credentials file
source ./backup-creds &> /dev/null || true

# Pretty printers
msg() { printf "\033[1;34m$* \033[0m\n" && (echo $* >> /tmp/backup.log); }
err() { printf "\033[1;31m$* \033[0m\n" && (echo ERROR: $* >> /tmp/backup.log); exit 1; }

# Handle ^C etc
function finish {
	# Uninstall trap to stop double trigger
	trap - INT TERM

	# Clean up files and processes
	rm -f /tmp/pkglist &> /dev/null &
	killall restic &> /dev/null &

	# Wait for cleanup tasks to finish 
	wait; err Interrupt received
}
trap finish INT TERM

# Exit on errors and pipe errors
set -e -o pipefail

# Clear old log
echo -n > /tmp/backup.log

# START!
msg Starting backup $(date)

# Sanic
echo -e "\033[0;33m"
cat << 'EOF'

                      -     =    .--._
                - - ~_=  =~_- = - `.  `-.
              ==~_ = =_  ~ -   =  .-'    `.
            --=~_ - ~  == - =   .'      _..:._
           ---=~ _~  = =-  =   `.  .--.'      `.
          --=_-=- ~= _ - =  -  _.'  `.      .--.:
            -=_~ -- = =  ~-  .'      :     :    :
             -=-_ ~=  = - _-`--.     :  .--:    D
               -=~ _=  =  -~_=  `;  .'.:   ,`---'@
             --=_= = ~-   -=   .'  .'  `._ `-.__.'
            --== ~_ - =  =-  .'  .'     _.`---'
           --=~_= = - = ~  .'--''   .   `-..__.--.
          jgs--==~ _= - ~-=  =-~_-   `-..___(  ===;
          --==~_==- =__ ~-=  - -    .'       `---'

EOF
echo -e "\033[0m"

# Status
restic snapshots -q &>> /tmp/backup.log & wait || { err "( ≖‿≖)"; }

# Snapshot /home subvolume
# msg Taking BTRFS snapshot...
# SNAP="/resticbackup"
# [ -d $SNAP ] && btrfs subvol del "$SNAP"
# if ! btrfs subvol snap /home "$SNAP" | tee -a /tmp/backup.log
# then
#   err Error taking filesystem snapshot
# fi

# Generate list of currently installed packages
msg Generating pkglist...
if ! pacman -Qqe | grep -v "$(pacman -Qmq)" | tee -a /tmp/backup.log 1> /tmp/pkglist
then
	err Error, couldn\'t generate a package list
fi

# Backup package list and cache
msg Backup package list and cache...
if ! restic backup --tag pacman --tag pkglist /tmp/pkglist -q | tee -a /tmp/backup.log
then
	err Error backing up pkglist
fi
if ! restic backup --tag pacman --tag cache /var/cache/pacman/pkg/ -q | tee -a /tmp/backup.log
then
	err Error backing up package cache
fi

# Backup home directory
msg Backup $HOME...
if ! restic backup --tag home --exclude-caches \
$HOME \ #--prefix $HOME --strip-components 1 $SNAP/$HOME \
-q | tee -a /tmp/backup.log
then
	err Could not backup home\!
fi

msg Completed