用openresty实现动态upstream

╰+哭是因爲堅強的太久メ 2022-07-15 05:26 372阅读 0赞

**前言：**  
此文的读者定义为对openresty有一定了解的读者。  
  
  
openresty：  
[https://github.com/openresty/lua-nginx-module][https_github.com_openresty_lua-nginx-module]  
  
  
**此文要讲什么：**  
大家都知道openresty可以用ngx.location.capture和ngx.exec来实现内部跳转，  
下面要讲怎么将ngx.location.capture和ngx.exec与upstream模块结合起来，实现一个动态的upstream。

下面的演示中：

80端口表示首次请求入口

8080端口表示upstream的出口

**直接上配置和源码：**

**配置： conf/nginx.conf**

worker_processes  1;
    error_log logs/error.log;
    events {
        worker_connections 1024;
    }
    
    http {
    
        log_format  main  '$msec $status $request $request_time '
                          '$http_referer $remote_addr [ $time_local ] '
                          '$upstream_response_time $host $bytes_sent '
                          '$request_length $upstream_addr';
    
        access_log  logs/access.log main buffer=32k flush=1s;
    
    
        upstream remote_hello {
            server 127.0.0.1:8080;
        }
    
        upstream remote_world {
            server 127.0.0.1:8080;
        }
    
        server {
            listen 80;
    
            location /capture {
                content_by_lua '
                    local test = require "lua.test"
                    test.capture_test()
                ';
            }
    
            location /exec {
                content_by_lua '
                    local test = require "lua.test"
                    test.exec_test()
                ';
            }
    
            location /upstream {
                internal;
    
                set $my_upstream $my_upstream;
                set $my_uri $my_uri;
                proxy_pass http://$my_upstream$my_uri;
            }
        }
    
    
        server {
            listen 8080;
            location /hello {
                echo "hello";
            }
    
            location /world {
                echo "world";
            }
        }
    }

**源码： lua/test.lua**

local _M = { _VERSION = '1.0' }
    
    function _M:capture_test()
        local res = ngx.location.capture("/upstream",
            {
                 method = ngx.HTTP_GET,
                 vars = {
                     my_upstream = "remote_hello",
                     my_uri = "/hello",
                 },
            }
        )
        if res == nil or res.status ~= ngx.HTTP_OK then
            ngx.say("capture failed")
            return
        end
        ngx.print(res.body)
    end
    
    function _M:exec_test()
        ngx.var.my_upstream = "remote_world"
        ngx.var.my_uri = "/world"
        ngx.exec("/upstream")
    end
    
    return _M

**运行效果：**  
![SouthEast][]

原文出自：[http://blog.csdn.net/daiyudong2020/article/details/53027934][http_blog.csdn.net_daiyudong2020_article_details_53027934]

End;

[https_github.com_openresty_lua-nginx-module]: https://github.com/openresty/lua-nginx-module
[SouthEast]: /images/20220715/376633ae4e314b7db353b21665e72602.png
[http_blog.csdn.net_daiyudong2020_article_details_53027934]: http://blog.csdn.net/daiyudong2020/article/details/53027934