HAProxy, health checking multiple servers with different host names
Solution 1:
defaults
log global
retries 2
timeout connect 3000
timeout server 5000
timeout client 5000
listen any-name-1
bind IP-Address:port
mode tcp or http
option user-check user haproxy_check
balance roundrobin
server hostname IpAddress:port check
server hostname IpAddress:port check
listen any-name-2
bind IP-Address:port
mode tcp or http
option user-check user haproxy_check
balance roundrobin
server hostname IpAddress:port check
server hostanme IpAddress:port check
listen any-name-3
bind IP-Address:port
mode tcp or http
option user-check user haproxy_check
balance roundrobin
server hostname IpAddress:port check
server hostname IpAddress:port check
listen any-name-4
bind IP-Address:port
mode tcp or http
option user-check user haproxy_check
balance roundrobin
server hostname IpAddress:port check
server hostname IpAddress:port check
listen any-name-5
bind IP-Address:port
mode tcp or http
option user-check user haproxy_check
balance roundrobin
server hostname IpAddress:port check
server hostname IpAddress:port check
listen haproxyadmin
bind HAproxyServerIP:HaproxyPort
mode http
stats enable
stats uri /haproxy
stats realm Strictly\ Private
stats auth username:password
Solution 2:
Update: In the case you described, you need HTTP/1.1 checks which require the host name hardcoded. Given the documentation of version 1.5, there doesn't seem to be a way to avoid this unless you can afford to drop the http checks (which of course is generally not recommended).
Original answer: While I am not familiar with the 1.5 changes of haproxy, what I would do in 1.4 (and I'm fairly sure it still applies in 1.5) is the following. Note that the frontend/backend separation is just a personal convenience and you could just use listen.
defaults
mode http
option httplog
timeout connect 5000
timeout client 10000
timeout server 10000
frontend inbound
bind 127.0.0.1:8000
default_backend webservers
backend webservers
option forwardfor
option httpchk HEAD / HTTP/1.0
http-send-name-header Host
server google www.google.com:80 check inter 5000 fall 3 rise 2
server bing www.bing.com:80 check inter 5000 fall 3 rise 2
And the result:
$ curl -i localhost:8000
HTTP/1.1 301 Moved Permanently
Cache-Control: no-cache
Content-Length: 0
Location: http://www.bing.com/
Server: Microsoft-IIS/8.0
P3P: CP="NON UNI COM NAV STA LOC CURa DEVa PSAa PSDa OUR IND"
Set-Cookie: _HOP=I=1&TS=1399981378; path=/
Edge-control: no-store
X-MSEdge-Ref: Ref A: 26CEE14531BF45EFAC91FAC3D1945EDF Ref B: 42CE8D142D427C30F7851B56F38837A6 Ref C: Tue May 13 04:42:58 2014 PST
Date: Tue, 13 May 2014 11:42:57 GMT
$ curl -i localhost:8000
HTTP/1.1 301 Moved Permanently
Location: http://www.google.com/
Content-Type: text/html; charset=UTF-8
X-Content-Type-Options: nosniff
Date: Tue, 13 May 2014 11:43:00 GMT
Expires: Thu, 12 Jun 2014 11:43:00 GMT
Cache-Control: public, max-age=2592000
Server: sffe
Content-Length: 219
X-XSS-Protection: 1; mode=block
Alternate-Protocol: 80:quic
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>301 Moved</TITLE></HEAD><BODY>
<H1>301 Moved</H1>
The document has moved
<A HREF="http://www.google.com/">here</A>.
</BODY></HTML>
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