1 前言

一个问题，一篇文章，一出故事。
笔者今天需要实现HAProxy代理sftp，因此整理此文。

2 最佳实践

2.1 实践环境

HAProxy集群环境，

如何使用HAProxy配置PostFix集群？

sftp服务环境，

如何基于Oracle Linux 9.x配置独立的SFTP服务？

2.2 配置代理

2.2.1 修改配置文件

vim /etc/haproxy/conf.d/sftp.cmdschool.org_115.cfg

加入如下配置，

listen sftp_115
    bind 0.0.0.0:115
    mode tcp
    option tcplog
    log /var/log/haproxy/haproxy.log local0 info
    timeout connect         15m
    timeout client          15m
    timeout server          15m
    server sftp.cmdschool.org 10.168.0.169:115 check

需要注意的是，参数“timeout connect”、“timeout client”、“timeout server”和“log”是有需要的，否则后面检查配置步骤会见到如下警告，

[WARNING]  (110660) : config : missing timeouts for proxy 'sftp_115'.
   | While not properly invalid, you will certainly encounter various problems
   | with such a configuration. To fix this, please ensure that all following
   | timeouts are set to a non-zero value: 'client', 'connect', 'server'.
[WARNING]  (110660) : config : log format ignored for proxy 'sftp_115' since it has no log address.
Warnings were found.
Configuration file is valid

另外，以上部分参数如果不设置，登录一分钟会有以下提示，

sftp -P 115 'cmdschool.org\will'@sftp.cmdschool.org
Password: 
Connected to sftp.cmdschool.org.
sftp> ls
myhome 
sftp> Connection to sftp.cmdschool.org closed by remote host.

2.2.2 检查配置

haproxy -c -f /etc/haproxy/conf.d

2.2.3 应用配置

systemctl reload haproxy.service
systemctl status haproxy.service

参阅文档
======================
https://www.mail-archive.com/haproxy@formilux.org/msg23817.html
https://haproxy.formilux.narkive.com/EpMmLH3G/for-sftp-load-balancing
https://www.cnblogs.com/rongfengliang/p/10319205.html
https://jakec007.github.io/2021-03-09-load-balancing-ssh-with-haproxy/
https://docs.haproxy.org/2.2/configuration.html
https://www.haproxy.com/documentation/haproxy-configuration-tutorials/session-persistence/
https://www.haproxy.com/documentation/haproxy-configuration-tutorials/load-balancing/passive-ftp/