combine two request by openresty

.conf

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;
	upstream backend1 {
		server 127.0.0.1:8081;
	}

	init_by_lua 'cjson = require "cjson"';
	lua_code_cache off;

    server {
        listen       8084;
        server_name  localhost;
	
        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
	    proxy_pass http://backend1;
        }

	location /combine {
		proxy_pass http://backend1;
		default_type application/json;

		content_by_lua_block {
			ngx. req. read_body()                                       -- explicitly read the req body
			local data = ngx. req. get_body_data()
			local jsonBody = cjson. decode(data);
			if data then
				local reqs = { }
				--ngx. say("body data:")

				for key, value in pairs(jsonBody) do
					--ngx.print(key)
					--ngx.print(value.url)
					local param = { }					
					param["args"] = value.query

					local method = ngx.HTTP_GET
					if value.method == "POST" then
						method = ngx.HTTP_POST
						param["body"] = value.body
					end
					param["method"] = method

					local reqParam = { }
					reqParam[1] = value.url
					reqParam[2] = param

					table.insert(reqs, reqParam)
				end

				local resps = {ngx.location.capture_multi(reqs)}

				local reponseData = {}
				-- loop over the responses table
				for key, value in pairs(resps) do
					-- process the response table "resp"
					-- ngx.print(key)
					-- ngx.print(value.body)

					--ngx.say(jsonBody[key].url)

					local theUrl = jsonBody[key].url
					reponseData[theUrl] = value.body 
				end


				local responseJson = cjson.encode(reponseData)


				ngx.header["Content-Type"] = "application/json; charset=UTF-8"

				ngx.say(responseJson)
			end


		}	
	}
		
		
		
        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

        # proxy the PHP scripts to Apache listening on 127.0.0.1:80
        #
        #location ~ \.php$ {
        #    proxy_pass   http://127.0.0.1;
        #}

        # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
        #
        #location ~ \.php$ {
        #    root           html;
        #    fastcgi_pass   127.0.0.1:9000;
        #    fastcgi_index  index.php;
        #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
        #    include        fastcgi_params;
        #}

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #    deny  all;
        #}
    }


    # another virtual host using mix of IP-, name-, and port-based configuration
    #
    #server {
    #    listen       8000;
    #    listen       somename:8080;
    #    server_name  somename  alias  another.alias;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}


    # HTTPS server
    #
    #server {
    #    listen       443 ssl;
    #    server_name  localhost;

    #    ssl_certificate      cert.pem;
    #    ssl_certificate_key  cert.key;

    #    ssl_session_cache    shared:SSL:1m;
    #    ssl_session_timeout  5m;

    #    ssl_ciphers  HIGH:!aNULL:!MD5;
    #    ssl_prefer_server_ciphers  on;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}

}

combine.lua

cjson = require "cjson"
ngx. req. read_body()                                       -- explicitly read the req body
local data = ngx. req. get_body_data()
local jsonBody = cjson. decode(data);
if data then
  local reqs = { }
  --ngx. say("body data:")

  for key, value in pairs(jsonBody) do
    --ngx.print(key)
    --ngx.print(value.url)
    local param = { }					
    param["args"] = value.query

    local method = ngx.HTTP_GET
    if value.method == "POST" then
      method = ngx.HTTP_POST
      param["body"] = value.body
    end
    param["method"] = method

    local reqParam = { }
    reqParam[1] = value.url
    reqParam[2] = param

    table.insert(reqs, reqParam)
  end

  local resps = {ngx.location.capture_multi(reqs)}

  local reponseData = {}
  -- loop over the responses table
  for key, value in pairs(resps) do
    -- process the response table "resp"
    -- ngx.print(key)
    -- ngx.print(value.body)

    --ngx.say(jsonBody[key].url)

    local theUrl = jsonBody[key].url
    reponseData[theUrl] = value.body 
  end


  local responseJson = cjson.encode(reponseData)

  ngx.header["Content-Type"] = "application/json; charset=UTF-8"

  ngx.say(responseJson)
end