snaproot

#!/usr/bin/env bash
#-*-coding:utf-8 -*-
#Auto updated?
#   Yes
#File :
#   snaproot
#Author :
#   The-Repo-Club [wayne6324@gmail.com]
#Github :
#   https://github.com/The-Repo-Club/
#
#Created:
#   Sun 17 July 2022, 11:03:52 PM [GMT+1]
#Last edited:
#   Sun 31 July 2022, 05:02:25 PM [UTC]
#
#Description:
#   <Todo>
#
#Dependencies:
#   <None>
#
# shellcheck disable=all

set -e

SNAP_ROOT=$(snapexec root | sed s/\'//g)
SNAP_PACMAN=$(snapexec pacman | sed s/\'//g)

## Script metadata
SCRIPTNAME=${0##*/}
VERSION="2021.09.19"
DESCRIPTION="A bash BTRFS Sanpshot wrapper"
AUTHOR="The-Repo-Club <wayne6324@gmail.com>"

## Set Colors (copied from makepkg)
ALL_OFF="\e[1;0m"
RED="\e[1;31m"
GREEN="\e[1;32m"
YELLOW="\e[1;33m"
BLUE="\e[1;34m"
PURPLE="\e[1;35m"
CYAN="\e[1;36m"

readonly ALL_OFF RED GREEN YELLOW BLUE PURPLE CYAN

#=== FUNCTION =================================================================
#        Name: error
# Description: Print message with a red pretag an ERROR
# Parameter 1: Message to print
#==============================================================================

# copied from makepkg
error() {
  local mesg=$1
  shift
  printf "${RED}==> ERROR:${ALL_OFF}${BOLD} %s${ALL_OFF}\n" "$mesg" "$@" >&2
}

#=== FUNCTION =================================================================
#        Name: main
# Description: The main function if nothing is passed
#==============================================================================

main() {
  #number of snapshots allowed
  sn=$SNAP_ROOT

  runas=$(whoami)

  if [ $runas != 'root' ]; then
    printf ${GREEN}"%s ${RED}command must be ran as root\n" "$SCRIPTNAME"
    exit
  fi

  #root subvolume device
  hsvdvl=1
  while IFS= read -r Line; do
    if [ -n "$hsvdvl" ]; then
      unset hsvdvl
      continue
    fi
    set -- $Line
    [ "$2" = 'btrfs' ] && [ "${7}" = '/' ] && hsvdv="$1"
  done <<<$(df -Th)

  #current date
  cdt=$(date +"%F-%H-%M-%S")

  #root subvolume
  while IFS= read -r Line; do
    set -- $Line
    [ "$7" = '5' ] && [ "$9" = '@' ] && hsv="${@: -1}"
  done <<<$(btrfs subvolume list /)

  #snapshot subvolume
  while IFS= read -r Line; do
    set -- $Line
    [ "$7" = '5' ] && [ "$9" = '@.snapshots' ] && ssv="${@: -1}"
  done <<<$(btrfs subvolume list /)

  #number of root snapshots
  hsl=0
  while IFS= read -r Line; do
    LastColumn=${Line##* }
    [ "${LastColumn:0:17}" = '@.snapshots/@root' ] && [ "${LastColumn:17:7}" != '-pacman' ] && hsl=$((hsl + 1))
  done <<<$(btrfs subvolume list /)

  #oldest root snapshot
  while IFS= read -r Line; do
    LastColumn=${Line##* }
    [ "${LastColumn:0:17}" = '@.snapshots/@root' ] && [ "${LastColumn:17:7}" != '-pacman' ] && ohs="$LastColumn" && break
  done <<<$(btrfs subvolume list /)

  #Mount root subvolume to /mnt/500GB/.snapshots
  mnt=$(snapexec mnt | sed s/\'//g)

  $(mount $hsvdv $mnt)

  if [ -e "$hsvdv" ]; then
    if [ -d "$mnt" ]; then
      printf "${YELLOW}Mounted $hsvdv to $mnt${ALL_OFF}\n"
    else
      printf "${RED}No btrfs drives found${ALL_OFF}\n"
      exit 1
    fi
  else
    printf "${RED}No btrfs drives found${ALL_OFF}\n"
    exit 1
  fi

  #MUST be in /mnt to perform task
  cd $mnt

  # Check root subvolume exists...
  if [ -e "$hsv" ]; then
    printf "${GREEN}Found root subvolume... $hsv${ALL_OFF}\n"
  else
    printf "${RED}No root subvolume found... exiting${ALL_OFF}\n"
    exit 1
  fi

  # check snapshot subvolume exists...
  if [ -e "$ssv" ]; then
    printf "${GREEN}Found snapshot suvolume... $ssv${ALL_OFF}\n"
  else
    printf "${RED}No snapshot subvolume found${ALL_OFF}\n"

    exit 1
  fi

  #Make snapshot and place in snapshot directory
  btrfs subvolume snapshot $hsv $ssv/@root-$cdt

  #remove a root snapshot if there are more than 5
  printf "${PURPLE}Found $hsl snapshots...${ALL_OFF}\n"
  if [ "$hsl" -ge "$sn" ]; then
    printf "${RED}Removing oldest $hsv snapshot... $ohs${ALL_OFF}\n"
    btrfs subvolume delete $ohs
  else
    printf "${YELLOW}Not enough $hsv snapshots...${ALL_OFF}\n"
    printf "${YELLOW}No snapshots to delete...${ALL_OFF}\n"
  fi

  printf "\n"
  cd ..
  $(umount $hsvdv)
}

#=== FUNCTION =================================================================
#        Name: pacman
# Description: this is ran if -p or --pacman is ran
#==============================================================================

pacman() {
  #number of snapshots allowed
  sn=$SNAP_PACMAN

  runas=$(whoami)

  if [ $runas != 'root' ]; then
    printf ${GREEN}"%s ${RED}command must be ran as root\n" "$SCRIPTNAME"
    exit
  fi

  #root subvolume device
  hsvdvl=1
  while IFS= read -r Line; do
    if [ -n "$hsvdvl" ]; then
      unset hsvdvl
      continue
    fi
    set -- $Line
    [ "$2" = 'btrfs' ] && [ "${7}" = '/' ] && hsvdv="$1"
  done <<<$(df -Th)

  #current date
  cdt=$(date +"%F-%H-%M-%S")

  #root subvolume
  while IFS= read -r Line; do
    set -- $Line
    [ "$7" = '5' ] && [ "$9" = '@' ] && hsv="${@: -1}"
  done <<<$(btrfs subvolume list /)

  #snapshot subvolume
  while IFS= read -r Line; do
    set -- $Line
    [ "$7" = '5' ] && [ "$9" = '@.snapshots' ] && ssv="${@: -1}"
  done <<<$(btrfs subvolume list /)

  #number of root snapshots
  hsl=0
  while IFS= read -r Line; do
    LastColumn=${Line##* }
    [ "${LastColumn:0:24}" = '@.snapshots/@root-pacman' ] && hsl=$((hsl + 1))
  done <<<$(btrfs subvolume list /)

  #oldest root snapshot
  while IFS= read -r Line; do
    LastColumn=${Line##* }
    [ "${LastColumn:0:24}" = '@.snapshots/@root-pacman' ] && ohs="$LastColumn" && break
  done <<<$(btrfs subvolume list /)

  #Mount root subvolume to /mnt/500GB/.snapshots
  mnt=$(snapexec mnt | sed s/\'//g)

  $(mount $hsvdv $mnt)

  if [ -e "$hsvdv" ]; then
    if [ -d "$mnt" ]; then
      printf "${YELLOW}Mounted $hsvdv to $mnt${ALL_OFF}\n"
    else
      printf "${RED}No btrfs drives found${ALL_OFF}\n"
      exit 1
    fi
  else
    printf "${RED}No btrfs drives found${ALL_OFF}\n"
    exit 1
  fi

  #MUST be in /mnt to perform task
  cd $mnt

  # Check root subvolume exists...
  if [ -e "$hsv" ]; then
    printf "${GREEN}Found root subvolume... $hsv${ALL_OFF}\n"
  else
    printf "${RED}No root subvolume found... exiting${ALL_OFF}\n"
    exit 1
  fi

  # check snapshot subvolume exists...
  if [ -e "$ssv" ]; then
    printf "${GREEN}Found snapshot suvolume... $ssv${ALL_OFF}\n"
  else
    printf "${RED}No snapshot subvolume found${ALL_OFF}\n"

    exit 1
  fi

  #Make snapshot and place in snapshot directory
  btrfs subvolume snapshot $hsv $ssv/@root-pacman-$cdt

  #remove a root snapshot if there are more than 5
  printf "${PURPLE}Found $hsl snapshots...${ALL_OFF}\n"
  if [ "$hsl" -ge "$sn" ]; then
    printf "${RED}Removing oldest $hsv snapshot... $ohs${ALL_OFF}\n"
    btrfs subvolume delete $ohs
  else
    printf "${YELLOW}Not enough $hsv snapshots...${ALL_OFF}\n"
    printf "${YELLOW}No snapshots to delete...${ALL_OFF}\n"
  fi

  printf "\n"
  cd ..
  $(umount $hsvdv)
}

#=== FUNCTION =================================================================
#        Name: version
# Description: Prints version information
#==============================================================================

version() {
  printf "
        %s v%s - %s

        This program may be freely redistributed
        under the terms of The MIT License.
        %s
    \n" "$SCRIPTNAME" "$VERSION" "$DESCRIPTION" "$AUTHOR"
  exit
}

#=== FUNCTION =================================================================
#        Name: usage
# Description: Prints the usage
#==============================================================================

usage() {

  printf "
    Snapshot the @ and @root btrfs subvolumes.
    Usage:
      %s...
      %s [options]...
    Options:
      -h, --help            Display help.
      -v, --version         Print version information and exits.
      -p, --pacman          Exec the scripts with the pacman hook.
      \n" "$SCRIPTNAME" "$SCRIPTNAME"
}

while true; do
  case $1 in
  -h | --help | -\?)
    usage
    exit 0
    ;;
  -v | --version)
    version
    exit 0
    ;;
  -p | --pacman)
    pacman
    exit 0
    ;;
  --)
    shift
    break
    ;;
  -*)
    error "Unknown option: $1"
    usage
    exit 1
    ;;
  *)
    main
    break
    ;;
  esac
done