nginx根据请求体内容进行条件代理传递

Question

我正在尝试将 nginx 配置为代理将请求传递到另一台服务器，前提是 $request_body 变量与特定正则表达式匹配。但这对我不起作用。

 server{
        listen 80 default;
        server_name www.applozic.com;

        location / {
                 proxy_set_header X-Real-IP $remote_addr;
                 proxy_set_header X-Forwarded-For $remote_addr;
                 proxy_set_header Host $http_host;

                if ($request_body ~* (.*)appId(.*)) {
                   proxy_pass http://apps.applozic.com;
                }
        }

}

请求正文是::

              {
               "applicationId": "appId",
               "authenticationTypeId": 1,
               "enableEncryption": false,
               "notificationMode": 0,
               "deviceType": 4,
              }

Answer 1

我找到了解决方案。

我在 nginx（打开 Resty）配置文件中做了以下更改

upstream algoapp {
   server 127.0.0.0.1:543;
}
upstream main {
   server 127.0.0.1:443;
}

location /rest/ws/login {
   proxy_set_header X-Forwarded-Host $host;
   proxy_set_header X-Forwarded-Server $host;
   proxy_set_header X-Real-IP $remote_addr;
   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   proxy_set_header X-Url-Scheme $scheme;
   proxy_set_header X-Forwarded-Proto $scheme;
   proxy_set_header Host $http_host;
   proxy_redirect off;
   if ($request_method = OPTIONS ) {
   proxy_pass https://127.0.0.1:543;
   }
   if ($request_method = POST ) {
   set $upstream '';
   access_by_lua '
   ngx.req.read_body()
   local data = ngx.req.get_body_data()
   local  match = ngx.re.match(ngx.var.request_body, "appId")
   if match then
      ngx.var.upstream = "algoapp"
   else
   ngx.var.upstream = "main"
   end
   ';
   proxy_pass https://$upstream;
   }
}

Answer 2

据我所知，问题是变量

$request_body

在执行 if 语句时可能尚未读入内存。

建议的替代方案是使用 lua 支持或 使用 echo 模块编译 nginx 并运行 echo_request_body。

Answer 3

一个带有自动化测试的工作示例，以防对其他人有用：https://github.com/ericminio/learning-nginx/tree/master/payload_filter

配置

map $request_body $matching {
    default       'not_matching';
    include       /etc/nginx/conf.d/matching;
}

server {                                                                              
    default_type  text/plain;

    location /ping {
        return 200 'pong';
    }

    location / {  
        proxy_set_header 'X-Matching' $matching;
        proxy_pass http://localhost/routing;           
    } 

    location /routing {
        try_files /unknown-file-to-trigger-redirect @_$http_x_matching;
    }
    location @_matching {
        proxy_pass http://host.docker.internal:5015;
    }
    location @_not_matching {
        proxy_pass http://host.docker.internal:5066;
    } 

}

Answer 4

使用集成时并不那么容易，比如某些情况下你的 nginx 不允许你做额外的代理东西来改变整个设计，那么你可以尝试 nginx-if-request-body 来实现结果

http {
 ....
     
 map "$uri" $forward_status {
    default 100; # 100 means nothing return, continue to proxy phase
    "~*.+?\.(css|js|bmp|gif|ico|jpeg|jpg|pict|png|svg|swf|tif)$" 418;
 }
 map "$request_body" $forward_status_by_body {
    default 100;
    "abc123xxx" 418;
    "~*.+?\.(css|js|bmp|gif|ico|jpeg|jpg|pict|png|svg|swf|tif)$" 418;
  }

server {
 ...
    error_page 418 =200 @welcome_if_request_body;

    location @welcome_if_request_body {
        add_header Content-Type text/plain;
        return 200 "welcome_if_request_body, you hit it";
    }

    location = / {
        if_request_body on;
        return_status_if_body_eq "ASD" 418 on;
        return_status_if_body_eq "foo" 418;
        return_status_if_body_eq "john" 418;
        return_status_if_body_startswith "report" 418;
        return_status_if_body_contains "report" 418;
        return_status_if_body_regex "^[\d]+?abc" 418;
        return_status_if_variable_map_to $forward_status;
        return_status_if_variable_map_to $forward_status_by_body;
        proxy_pass http://localhost:7777;

    }
...
  }
}

Answer 5

njs 模块的示例使用 r.internalRedirect 在 nginx 内部传递请求，以便可以填充和使用 r.requestText。 Nginx 需要在内部传递请求来填充 body 变量。

https://github.com/nginx/njs-examples