基于Lua的Spring Cloud网关高可用通用Ngnix插件

Posted 2022-11-27 ZhiYuanYe

项目github地址：点击跳转

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场景痛点

在Spring Cloud微服务架构体系中，我们往往会部署一个Zuul集群来横向扩展我们的微服务应用，集群的上层是nginx软负载，在实际情况中，往往会遇到Zuul宕机的尴尬事情，这时候从Nginx到这台机器的请求就会全部失效。此项目针对此痛点，用lua脚本实现定时拉取特定服务地址，动态无感知增减Zuul在Nginx中的负载节点。

如果您希望实现从Nginx直接到普通服务的动态节点负载，在下文配置服务名与Eureka注册中心地址即可。

OpenResty安装与配置

1、环境
yum -y install readline-devel pcre-devel openssl-devel gcc
2、下载解压OpenResty包
wget https://openresty.org/download/openresty-1.13.6.1.tar.gz
tar -zxvf openresty-1.13.6.1.tar.gz
3、下载ngx_cache_purge模块，该模块用于清理nginx缓存
cd openresty-1.13.6.1/bundle
wget http://labs.frickle.com/files/ngx_cache_purge-2.3.tar.gz
tar -zxvf ngx_cache_purge-2.3.tar.gz
4、下载nginx_upstream_check_module模块，该模块用于upstream健康检查
wget https://github.com/yaoweibin/nginx_upstream_check_module/archive/v0.3.0.tar.gz
tar -zxvf v0.3.0.tar.gz
5、OpenResty配置增加
cd openresty-1.13.6.1
./configure --prefix=/usr/servers --with-http_realip_module  --with-pcre  --with-luajit --add-module=./bundle/ngx_cache_purge-2.3/ --add-module=./bundle/nginx_upstream_check_module-0.3.0/ -j2 
6、编译安装
make
make install

7、OpenResty没有http模块，需要单独安装
cd /usr/servers/lualib/resty
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http_headers.lua  
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http.lua

8、项目脚本拷贝到这里
copy dynamic_eureka_balancer.lua into this dir
9、Nginx配置文件
vim /usr/servers/nginx/conf/nginx.conf

Nginx配置

http 
    #sharing cache area
    lua_shared_dict dynamic_eureka_balancer 128m;

    init_worker_by_lua_block 
        -- init eureka balancer
        local file = require "resty.dynamic_eureka_balancer"
        local balancer = file:new(dict_name="dynamic_eureka_balancer")

        --eureka server list
        balancer.set_eureka_service_url("127.0.0.1:8888", "127.0.0.1:9999")

        --The service name that needs to be monitored
        balancer.watch_service("zuul", "client")
    

    upstream springcloud_cn 
        server 127.0.0.1:666; # Required, because empty upstream block is rejected by nginx (nginx+ can use 'zone' instead)

        balancer_by_lua_block     

            --The zuul name that needs to be monitored
            local service_name = "zuul"

            local file = require "resty.dynamic_eureka_balancer"
            local balancer = file:new(dict_name="dynamic_eureka_balancer") 

            --balancer.ip_hash(service_name) --IP Hash LB
            balancer.round_robin(service_name) --Round Robin LB
        
    

    server 
        listen       80;
        server_name  localhost;

        location / 
            proxy_pass  http://springcloud_cn/;
            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto  $scheme;
        

        error_page   500 502 503 504  /50x.html;
        location = /50x.html 
            root   html;