安装 memcached

yum install -y memcached
#启动memcached服务，端口11211，以nobody身份启动，-d后台模式运行
memcached -p11211 -u nobody -d
#将自己的IP设为灰度测试的IP
telnet 127.0.0.1 11211
set 119.32.216.122 0 0 1
1
quit

安装 memcached for lua

wget https://github.com/openresty/lua-resty-memcached/archive/v0.11.tar.gz
tar -zxvf v0.11.tar.gz
mkdir -p /usr/local/share/lua/5.1
cp -r lua-resty-memcached-0.11/lib/resty /usr/local/share/lua/5.1

创建 test.lua 文件

clientIP=ngx.req.get_headers()["X-Real-IP"]
if clientIP == nil then
    clientIP=ngx.req.get_headers()["x_forwarded_for"]
end
if clientIP == nil then
    clientIP=ngx.var.remote_addr
end
    local memcached=require "resty.memcached"
    local memc,err=memcached:new()
    if not memc then
        ngx.say("failed to instantiate memc:",err)
        return
    end
    local ok,err =memc:connect("127.0.0.1",11211)
    if not ok then
        ngx.say("failed to connect:",err)
        return
    end
    local res,flags,err =memc:get(clientIP)
    --ngx.say("value key: ",res,clientIP)
    if err then
        ngx.say("failed to get clientIP",err)
        return
    end
    if res == "1" then
        ngx.exec("@server_test")
        return
    end
    ngx.exec("@server_product")

nginx配置

    server {
        listen 8867;
        server_name www.siguoya.name;
        root /usr/local/nginx/1.12.1/html;
        location / {
            content_by_lua_file /etc/nginx/test.lua;
        }
        location /hello {
            default_type text/plain;
            content_by_lua 'ngx.say("hello lua")';
        }
        location /ua {
            default_type text/plain;
            content_by_lua '
                clientIP=ngx.req.get_headers()["USER-AGENT"]
                ngx.say("IP:",clientIP)
                ';
        }
        location @server_product {
            default_type text/plain;
            return 200 'product';
        }
        location @server_test {
            default_type text/plain;
            return 200 'test';
        }
    }

由于我们将 119.32.216.122 这个IP添加进了memcached中，因此访问 http://www.siguoya.name:8867/ 的时候，看到的内容就是 test
而开启全局代理之后，发现看到的内容就是 product，这样就实现了针对部分用户进行灰度测试的效果