HAProxy:多个网站，但其中只有一个需要使用所有后端

Question

我目前有一个HAproxy负载平衡器设置与2个后端，共3个网站。其中一个网站需要额外的服务器(一个新后端，后端#3)，但其他网站不需要使用这个后端。有办法这样做吗？遗憾的是，我无法使用文档来解决这个问题。配置添加。新的后端将是.77。谢谢!

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global
	log /dev/log	local0
	log /dev/log	local1 notice
	chroot /var/lib/haproxy
	stats socket /run/haproxy/admin.sock mode 660 level admin
	stats timeout 30s
	user haproxy
	group haproxy
	maxconn 2000
	daemon

	# Default SSL material locations
	ca-base /etc/ssl/certs
	crt-base /etc/ssl/private

	# Default ciphers to use on SSL-enabled listening sockets.
	# For more information, see ciphers(1SSL). This list is from:
	#  https://hynek.me/articles/hardening-your-web-servers-ssl-ciphers/
	ssl-default-bind-ciphers ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+3DES:!aNULL:!MD5:!DSS
	ssl-default-bind-options no-sslv3

	# use 7 of 8 cores, bind stats to the 7th. We want one core for OS and stuff :)
	
	nbproc 7
        cpu-map 1 1
        cpu-map 2 2
        cpu-map 3 3
        cpu-map 4 4
        cpu-map 5 5
        cpu-map 6 6
        cpu-map 7 7
        stats bind-process 7

defaults
	log	global
	mode	http
	option	httplog
	option	dontlognull
	option  forwardfor
	option  http-server-close
        timeout connect 5000
        timeout client  50000
        timeout server  50000
	errorfile 400 /etc/haproxy/errors/400.http
	errorfile 403 /etc/haproxy/errors/403.http
	errorfile 408 /etc/haproxy/errors/408.http
	errorfile 500 /etc/haproxy/errors/500.http
	errorfile 502 /etc/haproxy/errors/502.http
	errorfile 503 /etc/haproxy/errors/503.http
	errorfile 504 /etc/haproxy/errors/504.http


listen stats 192.168.3.78:1936
	stats enable
	stats uri /

frontend www-http
	bind 1.2.3.4:80
	bind 192.168.3.78:80
	reqadd X-Forwarded-Proto:\ http
	bind-process 1
	default_backend www-backend

frontend www-https
	bind 1.2.3.4:443 ssl crt /etc/ssl/private/1.full-pem crt /etc/ssl/private/2.full-pem crt /etc/ssl/private/3.full-pem 
	reqadd X-Forwarded-Proto:\ https
	option forwardfor
	bind-process 2 3 4 5 6
	default_backend www-backend

backend www-backend
	redirect scheme https if !{ ssl_fc }
        cookie SERVERID insert indirect nocache
	server www-1 192.168.3.75:80 check cookie www-1
	server www-2 192.168.3.74:80 check cookie www-2

​

Answer 1

关于“后端”一词的注意:您在问题中使用它来描述将被转发请求的服务。为了避免混淆，我将在这里使用server，backend将是一组server (以匹配HAProxy术语)。

您需要两个backend块，一个带两个server，另一个带三个。在frontend中，使用主机名选择正确的主机名：

frontend www-http
  [...]
  acl host_website3 hdr(host) -i website3.com         # match the new website
  use_backend www-backend-with3 if host_website3      # send it to the correct backend
  default_backend www-backend

backend www-backend
  redirect scheme https if !{ ssl_fc }
  cookie SERVERID insert indirect nocache
  server www-1 192.168.3.75:80 check cookie www-1
  server www-2 192.168.3.74:80 check cookie www-2

backend www-backend-with3                             # new backend here
  redirect scheme https if !{ ssl_fc }
  cookie SERVERID insert indirect nocache
  server www-1 192.168.3.75:80 check cookie www-1
  server www-2 192.168.3.74:80 check cookie www-2
  server www-3 192.168.3.77:80 check cookie www-3     # with a new server here