基于Lua的Spring Cloud网关高可用通用Ngnix插件

r囧r小猫 2022-05-24 08:07 72阅读 0赞

项目github地址：[点击跳转][Link 1]

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## 场景痛点 ##

![这里写图片描述][70]

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;
            }
        }
    }

[Link 1]: https://github.com/SpringCloud/nginx-zuul-dynamic-lb
[70]: /images/20220524/4349490144e34909a82e99ef49985fdf.png