根据用户请求的User-Agent，调度到不同的后端集群
用户请求Chrome调度到172.16.1.7:80
用户请求Firefox调度到172.16.1.8:80

#web1：Chrome站点定义
cat /etc/nginx/conf.d/www.qingchen.com.conf
server {
    listen 80;
    server_name www.qingchen.com;
    root /www
    location / {
        index index.html
    }
}
echo "Chrome-->web1" > /www/index.html

#web2：Firefox站点定义
cat /etc/nginx/conf.d/www.qingchen.com.conf
server {
    listen 8080;
    server_name www.qingchen.com;
    root /www
    location / {
        index index.html
    }
}
echo "Firefox-->web2" > /www/index.html

frontend web
    bind *:80
    mode http
    
    # acl规则-基于设备调度   chrome --www    firefox -- m
    acl chrome_agent hdr(User-Agent) -m sub -i chrome
    acl firefox_agent hdr(User-Agent) -m sub -i firefox
    
    # 调用
    use_backend www_cluster if chrome_agent
    use_backend blog_cluster if firefox_agent
    default_backend www_cluster

backend www_cluster
    balance roundrobin
    option httpchk HEAD / HTTP/1.1\r\nHost:\ www.qingchen.net
    server 172.16.1.7 172.16.1.7:80 check port 80 inter 3s rise 2 fall 3
    server 172.16.1.8 172.16.1.8:80 check port 80 inter 3s rise 2 fall 3

backend blog_cluster
    balance roundrobin
    option httpchk HEAD / HTTP/1.1\r\nHost:\ www.qingchen.net
    server 172.16.1.7 172.16.1.7:8080 check port 8080 inter 3s rise 2 fall 3
    server 172.16.1.8 172.16.1.8:8080 check port 8080 inter 3s rise 2 fall 3

curl -A "firefox" -HHost:www.qingchen.net http://10.0.0.5
curl -A "chrome" -HHost:www.qingchen.net http://10.0.0.5