使用场景：
需要根据截取url动态配置跳转路径，常见于访问内网不固定ip地址的文件图片，
请求地址：http://11.19.1.212:82/bimg4/32.52.62.42:222/downloadfile?filename=loc:12/data/20180208/15/2e0ae54dfd752210083404deed15269c_222403
实际需要访问的内网地址：http://32.52.62.42:222/downloadfile?filename=loc:12/data/20180208/15/2e0ae54dfd752210083404deed15269c_222403
nginx配置文件
server {
listen 83;
server_name localhost;
index index.html index.htm;
root d: /workspace-xxxx/xxx_web;
error_page 500 502 503 504 / 50x.html;
location = /50x.html {
root html;
}
location ^~ /xxx/ {
proxy_pass http: //192.168.60.36:8090/xxxx/;
proxy_redirect default;
proxy_set_header host $host;
proxy_set_header x - real - ip $remote_addr;
proxy_set_header x - forwarded - host $host;
proxy_set_header x - forwarded - server $host;
proxy_set_header x - forwarded - for $proxy_add_x_forwarded_for;
proxy_set_header upgrade $http_upgrade;
proxy_set_header connection "upgrade";
}
# 此处为截取请求地址中bimg4之后的路径，并赋给转发地址
location ^ ~ / bimg4 / {
if ($request_uri~ / bimg4 / (. * )) {
set $bucketid $1;
}
proxy_pass http: //$bucketid;
}
}