2023年1月21日，我的博客受到攻击宕机了4个小时左右。本文将介绍事件的经过，对根本原因的分析，及改进方案。

当天中午，我起床之后看到了UptimeRobot的报警邮件。有时一些网络或者服务器的短暂故障也会触发报警，但是当时距离收到报警邮件已经过去了近两个小时，所以事情显然没有这么简单。我简单检查后发现访问博客时有时完全无法连接，有时会返回504。

我ssh上去之后重启了一下所有Docker容器，但是故障依旧。top显示全部load average高达6.xx并且大部分的CPU使用来自php-fpm。检查nginx amplify图表之后发现过去几小时内nginx收到了大量的请求。

因为当天下午我计划和女朋友去采购年夜饭的食材，不想在这上面花费太多时间，于是我打开了Cloudflare的反向代理（橙色云图标）和Under attack模式，然后就出门了。

过了一段时间后就收到UptimeRobot的报警解除邮件，访问恢复。

我的博客上有一套监控和安全措施，以及一些自动化脚本来mitigate一些简单问题：

1. UptimeRobot用于监控可访问性，如果出现无法连接或异常的HTTP状态（5xx）则会发邮件报警
2. nginx amplify用于监控nginx和操作系统的指标，其中一些指标（例如磁盘使用，每秒请求数量）超过阈值之后会发邮件报警。
3. 如果每秒请求量超过阈值则会自动开启Cloudflare反向代理并升高安全等级。
4. WordPress的安全插件会自动block恶意请求。

受益于这些措施，博客在过去几年一直保持着近乎100%的uptime。作为一个每日访问量两位数的博客，4个小时的downtime并不是一个需要担心的问题，但是职业习惯还是让我想知道背后到底发生了什么，尤其是为什么这一系列措施都未能阻止宕机的发生。

中文版：使用K3s部署预算友好的ARM-X86混合Kubernetes集群 – Frank’s Weblog

Kubernetes were used for enterprise level services, which is heavy and expensive. Even for the least-expensive Digital Ocean, its managed Kubernetes starts with $12/month per node. Then I learned about K3s, a lightweight Kubernetes distribution that removes or lightens many of the components in Kubernetes, allowing K3s to run on smaller VMs and even Raspberry Pi while still having the Kubernetes’ features and scalability.

This article will demonstrate at how to build a budget friendly Kubernetes cluster using K3s on Oracle Cloud Free Tier and find a balance between fancy technology and cost. The goal is to migrate some of my personal services that I previously ran using Docker, including Matomo, Maraidb, Mastodon, and several personal services to Kubernetes. This article will focus on the high-level design and concepts, and will not cover specific implementation details.

Throughout 2022, the financial statements from tech companies were extensively discussed, and you probably have seen diagrams like this:

I later discovered that this diagram is known as Sankey Diagram, which is a type of flow diagram in which the width of the arrows is proportional to the flow rate of the depicted extensive property. The Sankey diagrams are often used in the visualization of material flow analysis. It can also visualize cost breakdowns.^[1]

I’ve been using Intuit Mint to manage my finance, however I feel that the budget and trends feature is not good enough: The pie chart and histogram that Mint provides doesn’t provide enough insight, and its budget feature is limited, for example, it’s not good at managing expenses that happens once but covers an extensive period of time.

English version: Deploying Budget Friendly ARM-X86 Hybrid Kubernetes Cluster with K3s – Frank’s Weblog

Kubernetes大多被用于企业级的服务，十分沉重且昂贵。即使是最便宜的DigitalOcean，其Managed Kubernetes最低也需要$12/月每节点。后来我了解到了K3s，一个轻量级的Kubernetes发行版。K3s移除或轻量化了Kubernetes中的很多组件，使得K3s可以运行在较小的VM甚至Raspberry Pi上，同时仍然拥有Kubernetes的可扩展性。

本文将研究如何使用K3s在免费的Oracle Cloud Free Tier上搭建一个预算友好的Kubernetes集群，并在炫酷技术和成本之间找到一个平衡，目标是将我之前使用Docker运行的一些个人服务，包括Matomo，Maraidb，Mastodon以及若干小工具迁移到Kubernetes上来。本文将侧重选型及概念，不会涉及具体实现细节。

English version: Backup and Restore Kubernetes Volumes with Velero Restic Integration – Frank’s Weblog

我搭建了一个Kubernetes集群，使用OpenEBS作为存储后端。我选择了Jiva作为存储引擎，Jiva是一个高可用的存储控制器，数据被复制到所有节点。为了确保数据的安全，我使用Velero及其Restic集成将卷备份到AWS S3。

安装

首先需要在本地电脑上安装 Velero CLI以控制Kubernetes集群上的Velero控制器，请参阅Velero Docs – Basic Install了解安装说明。

准备Kubernetes配置文件，其应位于.kube/config 并确保 kubectl get pod 返回正确的结果。

使用如下的格式创建一个AWS密钥文件，该密钥应具有访问在下一步骤中提供的S3存储桶的权限，记下该文件的路径。

中文版： 使用Velero Restic集成备份及恢复Kubernetes数据卷 – Frank’s Weblog

I built a Kubernetes cluster using OpenEBS as the storage backend. I selected Jiva as the storage engine, Jiva is a high-available storage controller, data is replicated to all nodes. To ensure the safety of the data, I used Velero and its Restic integration to backup the volumes to AWS S3.

Install

To install Velero CLI on your computer, see Velero Docs – Basic Install for install instructions.

Prepare the kubeconfig. The kubeconfig should be placed in .kube/config and make sure kubectl get pod returns the correct result.

Create an AWS credentials file with the following format, this credential should have access to the s3 bucket you provide below, note down the path to the file.