From 6f3dc2bc92a772d6b20b7093f87b7270646a4c91 Mon Sep 17 00:00:00 2001
From: Tristan Ancelet <tristanancelet@yahoo.com>
Date: Fri, 27 Oct 2023 15:01:31 -0500
Subject: [PATCH] Added my daily btrfs snapshot script

---
 Linux/scripts/do-daily-snapshot.sh | 107 +++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100755 Linux/scripts/do-daily-snapshot.sh

diff --git a/Linux/scripts/do-daily-snapshot.sh b/Linux/scripts/do-daily-snapshot.sh
new file mode 100755
index 0000000..fdb68de
--- /dev/null
+++ b/Linux/scripts/do-daily-snapshot.sh
@@ -0,0 +1,107 @@
+#!/usr/bin/bash
+
+
+###############################################################################
+# do-daily-backup.sh                                                          #
+###############################################################################
+# This script is my attempt at replicating the same function that timeshift   #
+# performs. This is a very simplified script to handle automated btrfs        #
+# snapshots via a daily cron entry.                                           #
+#                                                                             #
+# EX:                                                                         #
+# ```                                                                         #
+# 0 0 * * * /path/to/script                                                   #
+# ```                                                                         #
+#                                                                             #
+# Afer putting it in your crontab it will automatically handle your making    #
+# snapshots for your system and will only make up to the limit you set with   #
+# LIMIT.                                                                      #
+#                                                                             #
+# You will also have to configure your own subvols in the array decleration   #
+# SUBVOLS following the same format in the comments above it.                 #
+#                                                                             #
+###############################################################################
+
+
+# BEGIN: Variables
+
+## Reusable vars
+DATE=`date +%Y-%m-%d`
+### Getting the name of the script (as it will be the first thing passed to bash when executing)
+SCRIPT=`basename $0` 
+BACKUP_DIR=/.backups
+### Setting dir to house log files
+LOG_DIR=/var/log/$SCRIPT
+
+LOG_FILE=$LOG_DIR/$DATE.log
+
+## The amount of backups that are allowed of each configured subvols
+LIMIT=5
+
+## Because cron fucks our env, and loading /etc/bashrc doesn't always fix it
+alias btrfs='/usr/bin/btrfs'
+
+## The subvols that we want to backup
+### <actual-directory>:<name-of-backup-dir>
+declare -a SUBVOLS=(
+	/:root
+	/home:home
+)
+
+## To use to seperate named manual backups from automatic ones
+DATE_REGEX='[0-9]{4}-[0-9]{2}-[0-9]{2}'
+# END: Variables
+
+
+# BEGIN: Pre-Work Checks
+
+## This will check to make sure that the log directory has been created, if not it will create it
+[[ ! -d $LOG_DIR ]] && mkdir -p $LOG_DIR
+## Setting up the script to direct all output to the log file for this snapshot session
+exec > $LOG_FILE
+
+
+# END: Pre-Work Checks
+
+
+# BEGIN: Work
+for SUBVOL_INFO in ${SUBVOLS[@]}; do
+
+	## Stripping the delemited info out of the subvol entry
+	OIFS=$IFS
+	IFS=':'
+	read DIR NAME <<< "$SUBVOL_INFO"
+	IFS=$OIFS
+	echo "Subvol : $DIR, Name: $NAME"
+
+	SUBVOL_BACKUP_DIR=$BACKUP_DIR/$NAME
+
+	## This will handle creating the backup directory as well as the specific snapshot directory as well
+	[[ ! -d $SUBVOL_BACKUP_DIR ]] && mkdir -p $SUBVOL_BACKUP_DIR
+
+	## Implemented it this way so that it's less complex to handle when there are more backups than we are
+	## configured to keep. Definately a rather stupid way to implement it, but it works and requires less logic to handle
+	while true; do
+		## So that any manual ones I do (named pre-upgrade, etc) will remain. And it will only delete the
+		## Automatic timestamped ones
+		declare -a backups=( $( ls -1 $SUBVOL_BACKUP_DIR | grep -Eo $DATE_REGEX ) )
+		echo "${#backups[@]} backups were found the backup dir $SUBVOL_BACKUP_DIR"
+
+		if [[ ${#backups[@]} -ge $LIMIT ]]; then
+			SNAPSHOT_PATH="$SUBVOL_BACKUP_DIR/${backups[0]}"
+			echo "${#backups[@]} was found to be equal to or greater than $LIMIT. Deleting $SNAPSHOT_PATH."
+			btrfs subvol del "$SUBVOL_BACKUP_DIR/${backups[0]}"
+		else
+			break
+		fi
+
+		## Unsetting the backups list so that it can be reloaded again
+		unset backups $SNAPSHOT_PATH
+	done
+
+	SNAPSHOT=$SUBVOL_BACKUP_DIR/$DATE
+	## If the snapshot doesn't already exist, then create a new read-only snapshot
+	[[ ! -d $SNAPSHOT ]] && btrfs subvol snapshot -r $DIR $SNAPSHOT
+done
+
+# END: Work