openresty整合lua-resty-http实现根据固定参数转发请求

1 nginx_url_hash

Nginx第三方模块，如果后端服务器宕机会发生503,使用也不灵活

2 lua-resty-http

下载lua-resty-http
git 地址：https://github.com/pintsized/lua-resty-http

将http.lua，http_connect.lua，http_headers.lua三个文件拷贝到/app/openresty/lualib/resty目录下

local http = require("resty.http")  

local httpc = http.new()  
  
local resp, err = httpc:request_uri("http://10.10.100.24:8762", {  
    method = "GET",  
    path = "/sparksql/get/databases",  
    headers = {  
        ["User-Agent"] = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.111 Safari/537.36"  
    }  
})  
  
if not resp then  
    ngx.say("request error :", err)  
    return  
end  
  
 
ngx.status = resp.status  
  
  
for k, v in pairs(resp.headers) do  
    if k ~= "Transfer-Encoding" and k ~= "Connection" then  
        ngx.header[k] = v  
    end  
end  
  
ngx.say(resp.body)  
  
httpc:close()

编辑nginx配置文件

    location /restyhttp {
        default_type text/html;
        content_by_lua_file /app/openresty/luascript/restyhttp.lua;
    }

假如访问外网需要加nginx中假如dns地址

在nginx配置文件http模块中加入

resolver 8.8.8.8;

3 lua-resty-http根据url参数进行进行负载均衡

local http = require("resty.http")  

local httpc = http.new()  

local hosts = {"10.10.100.24:8762","10.10.100.24:8762"} -- 模拟测试两个IP
local item_id= ngx.var.arg_id -- url中传入参数名为id
local id_hash = ngx.crc32_long(item_id)
local index = (id_hash % 2) +1

local resp, err = httpc:request_uri("http://"..hosts[index], {  
    method = "GET",  
    path = "/sparksql/get/databases",  
    headers = {  
        ["User-Agent"] = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.111 Safari/537.36"  
    }  
})  
  
if not resp then  
    ngx.say("request error :", err)  
    return  
end  
  
 
ngx.status = resp.status  
  
  
for k, v in pairs(resp.headers) do  
    if k ~= "Transfer-Encoding" and k ~= "Connection" then  
        ngx.header[k] = v  
    end  
end  
  
ngx.say(resp.body)  
  
httpc:close()