Tutorial on Youqing Han - DevOps Engineer

Comprehensive DNS Guide

ihanyouqing#gmail.com (#->@) (Youqing Han) — Mon, 15 Sep 2025 10:00:00 +0800

Comprehensive DNS Guide

DNS (Domain Name System) is one of the most fundamental technologies in modern internet infrastructure. As a DevOps or SRE engineer, understanding DNS is crucial for troubleshooting, performance optimization, and system reliability. This comprehensive guide covers all DNS concepts you need to know for real-world scenarios and technical implementations.

DNS Fundamentals

What is DNS?

DNS is a hierarchical, distributed naming system that translates human-readable domain names (like hanyouqing.com) into IP addresses (like 104.21.25.158) that computers use to identify each other on the network.

CentOS下Nginx配置地理访问控制：限制仅允许特定地区/国家访问

ihanyouqing#gmail.com (#->@) (Youqing Han) — Mon, 01 Sep 2025 10:00:00 +0800

概述

需求来自某好友某生产环境，有古老的应用运行于远古的操作系统之上，年久失修，无人维护。某日，或老板/或领导/或客户，心血来潮提出一些需求，比如根据访问者的地理位置来限制对网站或API的访问。以应对以下场景：

合规性要求（如GDPR、数据本地化）
许可证限制（某些服务仅在特定国家可用）
安全防护（阻止来自特定地区的恶意流量）
业务需求（仅服务特定市场）

本文将详细介绍在CentOS系统上配置Nginx实现地理访问控制的多种方法。

方法一：使用Nginx GeoIP模块（推荐）

注意：CentOS 7兼容性

在CentOS 7上，默认的Nginx包可能不包含GeoIP模块。如果遇到模块缺失问题，请参考以下解决方案：

检查现有Nginx是否支持GeoIP：

nginx -V 2>&1 | grep -o with-http_geoip_module

如果支持，直接使用；如果不支持，选择以下方案之一：
- 使用防火墙规则（方法二）
- 使用第三方服务（方法三）
- 重新编译Nginx（见下方安装步骤）

1. 安装GeoIP模块

# 安装EPEL仓库
sudo yum install -y epel-release

# 安装GeoIP工具和数据库
yum -y install GeoIP GeoIP-devel GeoIP-data.noarch GeoIP geoipupdate geoipupdate-cron

# 检查Nginx是否已安装GeoIP模块
nginx -V 2>&1 | grep -o with-http_geoip_module

# 如果没有GeoIP模块，需要重新编译Nginx
# 安装编译依赖
sudo yum groupinstall -y "Development Tools"
sudo yum install -y pcre-devel zlib-devel openssl-devel libxml2-devel libxslt-devel gd-devel perl-devel perl-ExtUtils-Embed

# 安装Google perftools（如果启用该模块）
sudo yum install -y gperftools gperftools-devel

# 下载Nginx源码并编译（如果需要）
wget http://nginx.org/download/nginx-1.28.0.tar.gz
tar -xvf nginx-1.28.0.tar.gz
cd nginx-1.28.0

# 参数从原 nginx -V 中获取，追加 --with-http_geoip_module 
./configure --prefix=/usr/share/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib64/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --http-client-body-temp-path=/var/lib/nginx/tmp/client_body --http-proxy-temp-path=/var/lib/nginx/tmp/proxy --http-fastcgi-temp-path=/var/lib/nginx/tmp/fastcgi --http-uwsgi-temp-path=/var/lib/nginx/tmp/uwsgi --http-scgi-temp-path=/var/lib/nginx/tmp/scgi --pid-path=/run/nginx.pid --lock-path=/run/lock/subsys/nginx --user=nginx --group=nginx --with-compat --with-debug --with-file-aio --with-google_perftools_module --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_degradation_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_image_filter_module=dynamic --with-http_mp4_module --with-http_perl_module=dynamic --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-http_xslt_module=dynamic --with-mail=dynamic --with-mail_ssl_module --with-pcre --with-pcre-jit --with-stream=dynamic --with-stream_ssl_module --with-stream_ssl_preread_module --with-threads --with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic' --with-ld-opt='-Wl,-z,relro -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -Wl,-E' --with-http_geoip_module 

make && sudo make install

# 检查Nginx是否支持GeoIP模块
/usr/sbin/nginx -V 2>&1 | grep -o with-http_geoip_module

2. 下载MaxMind GeoIP数据库

# # 创建目录
# sudo mkdir -pv /usr/share/GeoIP

# # 下载GeoIP2数据库（需要Nginx支持geoip2模块）
# wget -P /usr/share/GeoIP https://github.com/P3TERX/GeoLite.mmdb/raw/download/GeoLite2-ASN.mmdb
# wget -P /usr/share/GeoIP https://github.com/P3TERX/GeoLite.mmdb/raw/download/GeoLite2-Country.mmdb
# wget -P /usr/share/GeoIP https://github.com/P3TERX/GeoLite.mmdb/raw/download/GeoLite2-City.mmdb
# ln -s /usr/share/GeoIP/GeoLite2-Country.mmdb /usr/share/GeoIP/GeoLite2-Country.dat

# 验证数据库文件
ls -la /usr/share/GeoIP/
geoiplookup 8.8.8.8

3. 配置Nginx

在/etc/nginx/nginx.conf中添加：

Complete macOS Development Environment Setup for SRE/DevOps Engineers

ihanyouqing#gmail.com (#->@) (Youqing Han) — Mon, 01 Sep 2025 00:00:00 +0000

Introduction

This guide is a synthesis of my personal configuration journey and best practices for SRE/DevOps engineers. It details how to set up a robust, reproducible macOS development environment, covering essential tools, configuration management, and automation strategies. The goal is to make environment setup painless, portable, and scalable—whether you’re starting over, joining a new team, or enabling seamless collaboration.

Prerequisites

Before we begin, ensure you have:

macOS 12.0 (Monterey) or later
Administrator access to your machine
Basic familiarity with command line operations
A GitHub account for configuration storage

Core Development Tools

Install required develop tools & Set update/upgrade

Infrastructure as Code Pipeline: Architecture with Terraform, GitHub Actions, and OCI Always Free Resources

ihanyouqing#gmail.com (#->@) (Youqing Han) — Fri, 22 Aug 2025 00:00:00 +0000

This article demonstrates a production-ready Infrastructure as Code pipeline that leverages OCI’s Always Free tier resources, making it perfect for learning, development, and small-scale production workloads.

Introduction

Infrastructure as Code (IaC) has revolutionized how we manage cloud infrastructure. By treating infrastructure configuration as code, we gain version control, automated deployments, consistency, and reproducibility. In this article, I’ll walk you through building a complete IaC pipeline using Terraform, GitHub Actions, and Oracle Cloud Infrastructure (OCI) Always Free resources.

Marp Slide Demo - DevOps Best Practices

ihanyouqing#gmail.com (#->@) (Youqing Han) — Mon, 27 Jan 2025 00:00:00 +0000

This is a demonstration of how Marp slides can be integrated with Hugo for creating professional technical presentations. The slides are defined in the front matter and rendered using the Marp template system.

Features Demonstrated

Title Slides: Professional opening and closing slides
Content Slides: Regular content with bullet points and formatting
Code Slides: Syntax-highlighted code examples
Section Slides: Clear section dividers
Navigation: Keyboard and mouse navigation
Responsive Design: Works on desktop and mobile
Fullscreen Mode: Professional presentation mode

Usage

To use this Marp integration in your own content:

Tutorial on Youqing Han - DevOps Engineer

Comprehensive DNS Guide

Comprehensive DNS Guide

Table of Contents

DNS Fundamentals

What is DNS?

CentOS下Nginx配置地理访问控制：限制仅允许特定地区/国家访问

概述

方法一：使用Nginx GeoIP模块（推荐）

1. 安装GeoIP模块

2. 下载MaxMind GeoIP数据库

3. 配置Nginx

Complete macOS Development Environment Setup for SRE/DevOps Engineers

Introduction

Prerequisites

Core Development Tools

Infrastructure as Code Pipeline: Architecture with Terraform, GitHub Actions, and OCI Always Free Resources

Introduction

Marp Slide Demo - DevOps Best Practices

Features Demonstrated

Usage