#img.test.com/img1 实际访问的路径是  http://127.0.0.1:123/a1

#img.test.com/img2 实际访问的路径是  http://127.0.0.1:123/a2

 location / {

                proxy_set_header Host img.test.com;

                rewrite img1/(.+)$  /a1/$  break;

                rewrite img2/(.+)$  /a2/$  break;

                proxy_pass http://127.0.0.1:123/;#代理ip:127.0.0.1,端口123

                proxy_redirect off;

                proxy_set_header X-Real-IP $remote_addr;

                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        }