nginx-1.15.2 版本新增了$ssl_preread_protocol 变量，通过该变量可以使用 stream 反向代理时预先判断连接是否为ssl/tls协议或者为非ssl/tls协议，从而实现同一个端口来转发不同的业务。
stream_ssl_preread模块检查初始ClientHello在SSL或TLS连接消息，并且提取其可用于管理连接几个值。$ssl_preread_protocol版本1.15.2中添加的变量从消息client_version字段中捕获最新的SSL / TLS版本号ClientHello。如果消息中supported_versions存在扩展名ClientHello，则变量设置为TLSv1.2/TLSv1.3。
实例：在一台反向代理服务器上运行Nginx，并监听443端口，后端有两组服务，一个为HTTPS(开启TLS1.2/1.3)网站服务，另一个为SSH 服务，我们要实现这两组服务运行在同一个端口上（配置的443端口）--入口请求由Nginx自动区分。
为简便，我这时直接使用 docker环境
nginx 版本
# docker exec -it nginx nginx -V nginx version: nginx/1.15.10 built by gcc 8.2.0 (Alpine 8.2.0) built with OpenSSL 1.1.1b 26 Feb 2019 ...<省略若干行>...
目录文件
# tree ./nginx-with-L4-reuse/./nginx-with-L4-reuse/ ├── config│ └── nginx │ ├── conf.d │ │ └── default.conf │ ├── fastcgi.conf │ ├── fastcgi_params │ ├── mime.types │ └── nginx.conf └── docker-compose.yaml 3 directories, 6 files
docker-compose.yaml
# docker-compose.yaml
version: "2.4"
services:
nginx:
container_name: nginx
image: nginx:alpine
network_mode: host
volumes:
- ./config/nginx:/etc/nginx/:ro
ports:
- "443:443"
restart: alwaysnginx.conf
user nginx;
worker_processes 2;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
stream {
log_format stream '{"@access_time":"$time_iso8601",'
'"clientip":"$remote_addr",'
'"pid":$pid,'
'"pro":"$protocol",'
'"ssl_pro": "$ssl_preread_protocol"',
'"pro":"$protocol",'
'"stus":$status,'
'"sent":$bytes_sent,'
'"recv":$bytes_received,'
'"sess_time":$session_time,'
'"up_addr":"$upstream_addr",'
'"up_sent":$upstream_bytes_sent,'
'"up_recv":$upstream_bytes_received,'
'"up_conn_time":$upstream_connect_time,'
'"up_resp_time":"$upstream_first_byte_time",'
'"up_sess_time":$upstream_session_time}';
upstream ssh {
server 192.168.50.212:22;
}
upstream web {
server 192.168.50.215:443;
}
map $ssl_preread_protocol $upstream {
default ssh;
"TLSv1.2" web;
"TLSv1.3" web;
}
# SSH and SSL on the same port
server {
listen 443;
proxy_pass $upstream;
ssl_preread on;
access_log /var/log/nginx/stream_443.log stream;
}
}$ssl_preread_protocol 实现IP层实现了不同业务配置，在某种需求上很有意义--虽然存在功能限制。然而Tengine-2.3.0已经实现的IP层基于域名转发，或许这一特性会引入到Nginx。
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