ZengXu's BLOG

Latest posts

Dive into Knative Pod Autoscaler

Understanding the Knative Pod Autoscaler (KPA) and its scaling mechanisms

Apr 9, 2025

Kubernetes v1.14.5 → v1.21.14 升级补遗及经验教训

Mar 26, 2024

Notes on Retriable HTTP Client (with Golang/Rust example

Notes on Retriable Http Client (with Golang/Rust example

Dec 22, 2023

v1.14.5 - v1.21.14 Kubernetes 跨版本升级记录

Nov 30, 2023

Calico ➕ KubeOVN —— 为 KubeVirt VMs 提供受限的 underlay 网络访问

Calico ➕ KubeOVN - providing restricted underlay network access for KubeVirt VMs

Aug 13, 2023

K8s API Admission Control and Policy

This post provides an overview of Admission Controllers in Kubernetes, including their implementation and usage. Third-party admission controllers can be integrated into kube-apiserver by implementing them as admission webhooks. Many policy engines have appeared in the community on top of admission webhooks. This post introduces two policy engines, OPA/Gatekeeper and Kyverno. Finally, it covers…

Jun 19, 2023

K8s 多版本 API 转换最佳实践

规范的 K8s APIVersion 往往会经历由 alpha 到 beta 最后到 stable 的过程，API 转换就成了应有之义。本文提供多版本 API 转换的最佳实践。本文详细讲述了基于 CRD 提供多版本 API 时的困境和解决办法，并提供了一个基于最佳实践的 Conversion Webhook Server 实现

Jun 19, 2023

慎重选用 Runtime 类框架开发 K8s apiserver

apiserver-runtime 本身也是基于 k8s.io/apiserver 提供增强。当项目需要灵活定制策略时，就不可避免需要直接使用底层库。结果是，开发者除了要熟悉 k8s.io 库，还需要再学一套框架。那为什么不从一开始直接使用 k8s.io/apiserver？

Jun 18, 2023

使用 library 实现 K8s apiserver

理解 K8s apiserver 的最好方式就是自己动手实现同款

Jun 7, 2023

最不厌其烦的 K8s 代码生成教程

彻底而全面的梳理，甚至提供了复制即用的脚本和镜像…

Jun 5, 2023

搞懂 K8s apiserver aggregation

全图文展示 apiserver aggregation 原理，彻底搞懂 APIService 和 custom apiserver 认证授权 (authn, authz)

May 31, 2023

实现一个极简 K8s apiserver

本文实现了一个符合 Kubernetes REST 风格的极简 apiserver，代码量只有 500 行左右。无论是单独运行还是集成到 K8s 集群，它都支持 kubectl 增删改查操作。动手把玩这个 apiserver，可以很好理解 K8s apiserver aggregation 原理，以及 kubectl 与 apiserver 的交互机制

May 25, 2023

K8s CustomResourceDefinitions (CRD) 原理

K8s CustomResourceDefinition (CRD) 为使用者提供了开箱即用的 REST API 拓展能力。使用方只需创建一份 CRD 声明，kube-apiserver 就会自动提供一套成熟的 HTTP REST API，并直接将 Custom Resources 存储到背后存储（通常是 etcd）中。本文由浅入深，先展示了 CRD 的基本使用方式、kubectl 与对应 Custom API 模块的交互原理，再深入探究 CRD 在 kube-apiserver 内部的实现原理，最后对其特性的利弊做了总结

May 19, 2023

Enable Kubelet Serving Certificates in Kubernetes Setup by Kubeadmin

Setting up a Kubernetes cluster with a newly deployed metrics server often results in the following error message: Failed to scrape node, err=Get https://172.18.0.3:10250/metrics/resource: x509: cannot validate certificate for 172.18.0.3 because it doesn't contain any IP SANs node=kind-worker . This can be frustrating. In this post, I will demonstrate how to solve this problem in KinD.

Apr 22, 2023

REST: Part 2 - HTTP 缓存

HTTP REST 缓存简述

Apr 7, 2023

REST: Part 1 - HTTP API 设计思路

HTTP REST API 通用设计思路

Apr 5, 2023

Http Range Request and MP4 Video Play in Browser

HTTP range request is a widely used feature when it comes to file resource. Besides covering basic concept of range request, this blog show how HTTP range request works in browsers. Behaviors of Chrome, FireFox and Safari are coverd. several sample HTTP servers written in Golang are used to trick browsers.

Mar 8, 2023

Terminate Container in Responsive and Graceful Way

Running application in container as PID 1 is quite common today, shutdown application responsively and gracefully is hard. This article show how PID 1 behave in container and provides serveral ways to make container shutdown as we want.

Feb 27, 2023