#!/bin/bash

savedays=7
num_keep_local=3
nas_backups="/home/artinx/.AutoBackup/nas-backups.log"
# volume path in synology nas
nas_target_path="/volume1/backup/jira"

timeshift --create
today=$(date -I)
cd /timeshift/snapshots
today_backup=$(ls | grep "$today")
# delete old local backups
ls -dt */ | tail -n +$((num_keep_local+1)) | xargs -I {} rm -rf {}
rsync -av "$today_backup" nas:${nas_target_path}/${today}
nas_today="/home/artinx/.AutoBackup/nas_today.log"
ssh nas "cd $nas_target_path; ls | grep $today; exit" >> "$nas_today"
while read -r line
do
    nas_backup=$line
done < "$nas_today"
rm /home/artinx/.AutoBackup/nas_today.log
check="$today_backup"
if [ "$nas_backup" = "$check" ]
then
    echo -e "$today\\nupload successfully\\n" >> /home/artinx/.AutoBackup/upload.log
else
    echo -e "$today\\nupload failed\\n" >> /home/artinx/.AutoBackup/upload.log
fi

# Auto delete full system backup(s)
ssh nas "cd $nas_target_path; ls" > "$nas_backups"
oldest=$(date --date="$today -$savedays days" +%s)
i=0
while read -r line
do
    filenames[$i]=$line
    ((++i))
done < "$nas_backups"
((--i))
first=true
echo "$today" >> /home/artinx/.AutoBackup/delete-history.log
count=0
for ((j=0; j!=i; ++j))
do
    if [ $(date --date="$(echo ${filenames[$j]} | cut -c1-10)" +%s) -le $oldest ]
    then
        ssh nas "rm -rf $nas_target_path/${filenames[$j]}"
        echo "delete ${filenames[$j]} from nas" >> /home/artinx/.AutoBackup/delete-history.log
        first=false
        ((++count))
    fi
done
if [ "$first" = true ]
then
    echo -e "delete nothing from nas\\n" >> /home/artinx/.AutoBackup/delete-history.log
else
    echo -e "totally delete $count file(s)\\n" >> /home/artinx/.AutoBackup/delete-history.log
fi

该脚本的主要功能是：

1. 创建本地 Timeshift 备份。
2. 将备份上传到 Synology NAS。
3. 删除超过指定保留时间（7天）的旧备份文件（无论是本地还是 NAS 上）。
4. 将每次备份的上传和删除操作结果记录在日志文件中。

详解：

0. 前提条件

需要备份的 Linux 系统可以直接通过 ssh 密钥连接群晖（或者你用来存放备份文件的机器），实现方法为如下：

1. 生成 SSH 密钥对

   已经生成的情况下请不要再次生成，以免影响运行中的备份服务！

   查看 ~/.ssh 文件夹确认是否已经存在 ssh 密钥。

 ssh-keygen -t rsa -b 4096 -C "[email protected]"

1. 将公钥复制到远程服务器

 ssh-copy-id username@remote_host

• username 是远程系统的用户名。
• remote_host 是远程系统的 IP 地址或主机名。

系统会提示输入该远程系统的密码，验证通过后，公钥将被添加到远程服务器的 ~/.ssh/authorized_keys 文件中。

1. 检查远程服务器的权限配置

确保远程服务器上的 ~/.ssh 目录及 authorized_keys 文件的权限设置正确：