HAproxy 虚拟主机

dfdh

　　http://www.oschina.net/bbs/thread/4089

　　
　　请特别注意配置中粗体部分的内容。
　　Until recently, I wasn’t aware of the ACL system in HAProxy, but once
I found it I realized that I have been missing a very important part
of  load balancing with HAProxy!
　　While the full configuration settings available for the ACL are  listed in the configuration  doc
, the below example includes the basics that you’ll need to  build an HAProxy load balancer that supports multiple host headers.
　　Here is a quick example haproxy configuration file that uses ACLs:

global
log 127.0.0.1 local0
log 127.0.0.1 local1 notice
maxconn 4096
user haproxy
group haproxy
daemon

defaults
log global
mode http
option httplog
option dontlognull
retries 3
option redispatch
maxconn 2000
contimeout 5000
clitimeout 50000
srvtimeout 50000

frontend http-in
bind *:80
acl is_www_example_com hdr_end(host) -i example.com
acl is_www_domain_com hdr_end(host) -i domain.com

use_backend www_example_com if is_www_example_com
use_backend www_domain_com if is_www_domain_com
default_backend www_example_com

backend www_example_com
balance roundrobin
cookie SERVERID insert nocache indirect
option httpchk HEAD /check.txt HTTP/1.0
option httpclose
option forwardfor
server Server1 10.1.1.1:80 cookie Server1
server Server2 10.1.1.2:80 cookie Server2

backend www_domain_com
balance roundrobin
cookie SERVERID insert nocache indirect
option httpchk HEAD /check.txt HTTP/1.0
option httpclose
option forwardfor
server Server1 192.168.5.1:80 cookie Server1
server Server2 192.168.5.2:80 cookie Server2

　　In HAProxy 1.3, the ACL rules are placed in a “frontend” and  
(depending on the logic) the request is proxied through to any number of
“backends”. You’ll notice in our frontend entitled “http-in” that I’m
checking the host header using the hdr_end feature. This feature  
performs a simple check on the host header to see if it ends with the  
provided argument.
　　You can find the rest of the Layer 7 matching options by searching  
for “7.5.3. Matching at Layer 7″ in the configuration doc I linked to  
above. A few of the options I didn’t use but you might find useful are  
path_beg, path_end, path_sub, path_reg, url_beg, url_end, url_sub, and  
url_reg. The *_reg commands allow you to perform RegEx matching on the  
url/path, but there is the usual performance consideration you need to  
make for RegEx (especially since this is a load balancer).
　　The first “use_backend” that matches a request will be used, and if  
none are matched, then HAProxy will use the “default_backend”. You can  
also combine ACL rules in the “use_backend” statements to match one or  
more rules. See the configuration doc for more helpful info.
　　If you’re looking to use HAProxy with SSL, that requires a different  approach, and I’ll blog about that soon.