nginx配置使用一个域名重定向到两个不同的项目站点

一、nginx配置文件：

server {
    listen 80;
    server_name a;
    root /a;
    index index.php index.htm index.html;

    location / {
         try_files $uri $uri/ /index.php$is_args$args;
    }
           location ^~ /b/ {
               proxy_pass     http://127.0.0.1:自定义/;
               proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
               proxy_set_header Host $host;
               proxy_set_header X-Real-IP $remote_addr;
           }
    location ~ \.php$ {
        try_files $uri /index.php =404;
        fastcgi_pass 127.0.0.1:9000;
        fastcgi_index index.php;
        fastcgi_buffers 16 16k;
        fastcgi_buffer_size 32k;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_read_timeout 600;
        include fastcgi_params;
    }

    access_log  a.log;
    err