简介：
haproxy为高性能的反向代理服务器，在向后端server调度方面支持很多的调度算法：roundrobin，source，uri，url_param，hdr()，leastconn等，且支持动态权重调整的一致性hash，后端为cache server时很好的提高cache命中率；相比nginx反向代理，haproxy调度功能更为强大，另外haproxy提供自带的gui接口，方便直接在web页面管理前、后端服务器，只需要在配置文件中开启即可。
nginx自身在处理web静态页面方面非常强大，其采用模块化设计，有较好的扩展性，但不支持模块动态装卸载（Tengine支持模块动态装卸载），nginx具有高可靠性，支持热部署，低内存消耗等优点，其在设计之初就吸纳了最新的技术，如支持事件驱动、异步IO等，并发处理能力强大。
apache结合php处理动态页面功能强大，php可直接以模块的形式加载到httpd，而nginx需要通过fastcgi协议与后端php通信。所以结合各组件优点，我们这里采用haproxy(支持https)+nginx(静态)+lamp(动态)架构，最后通过keepalived实现对haproxy高可用。
下图为本次实验架构图：
图1
图2
架构图说明
这里有2幅架构图，图1中，后端各主机均在同一网段，这也是我们这次实验所采用的架构；图2中后端static server group和dynamic server group不在同一网段，二者之间需要路由器相连，Router的地址：eth0 --> 192.168.100.80eth1 --> 192.168.200.80非但如此，采用图2架构还需在haproxy和各后端server上添加静态路由：
haproxy1： route add -net 192.168.200.0/24 gw 192.168.100.80 dev eth1
haproxy2： route add -net 192.168.100.0/24 gw 192.168.200.80 dev eth1
Nginx1： routeadd -net 192.168.200.0/24 gw 192.168.100.80 dev eth0
Nginx2： routeadd -net 192.168.200.0/24 gw 192.168.100.80 dev eth0
LAMP1： routeadd -net 192.168.100.0/24 gw 192.168.200.80 dev eth0
LAMP2： routeadd -net 192.168.100.0/24 gw 192.168.200.80 dev eth0
为简便，这里我们采用架构图1。这里我们用virtualbox准备6台linux主机，各主机IP地址、Gateway及所需安装软件等如下表所配置，这里我们将192.168.0.0/24网络模拟为公网，192.168.100.0/24为服务器内网网段。前端为2台haproxy组成的反向代理服务器，并实现双主高可用：所谓双主，即haproxy1和haproxy2都正常工作，均同时为后端server提供反向代理和调度功能，用户可通过DNS解析后的192.168.0.50和192.168.0.51两个地址访问我们的网站。客户端请求的所有phpBB静态页面由前端的haproxy调度至后端的2台nginx组成的服务器组响应；用户请求的所有phpBB动态页面由前端的haproxy调度至后端的2台lamp组成的服务器组响应。
6台linux主机上所需资源如下：
IP Address | Hosts Name | OS | Software Required | comments |
eth0 -->192.168.0.16; GW -->192.168.0.1 | HAProxy1(active) | centos6.8 | keepalived、haproxy、ntpd、双网卡 | HAProxy（active） |
eth0:0 -->192.168.0.50(由keepalived配置文件自动生成) | ||||
eth1 -->192.168.100.16 | ||||
eth0 -->192.168.0.66; GW -->192.168.0.1 | HAProxy2(active) | centos6.8 | keepalived、haproxy、双网卡 | HAProxy（active） |
eth0:1 -->192.168.0.51(由keepalived配置文件自动生成) | ||||
eth1 -->192.168.100.66 | ||||
eth0 -->192.168.100.64; GW -->192.168.100.16 | Nginx1 | centos6.8 | nginx、phpBB、单网卡 | Static Server Group |
eth0 -->192.168.100.65; GW -->192.168.100.66 | Nginx2 | centos6.8 | nginx、phpBB、单网卡 | |
enp0s3 -->192.168.100.70; GW -->192.168.100.16 | LAMP1 | centos7.3 | httpd、mariadb/mysql、php、单网卡、phpBB | Dynamic Server Group |
enp0s3 -->192.168.100.71; GW -->192.168.100.66 | LAMP2 | centos7.3 | httpd、mariadb/mysql、php、单网卡、phpBB |
软件安装
按照上面的清单，分别在各主机上部署所需软件，对于清单中HAProxy需要安装ntpd服务器的原因在于keepalived的运行需要后端server与前端服务器时钟保持同步，否则对后端server的健康状态检测会出现异常。
①、haproxy
haproxy在centos6.8上可以直接使用yum方式：
[root@centos68 ~]# yum install -y haproxy
目前系统提供的默认版本是1.5.18，且支持openssl：
[root@centos68 ~]# rpm -q haproxy ; ldd $(which haproxy)| grep ssl
haproxy-1.5.18-1.el6.x86_64
libssl.so.10 => /usr/lib64/libssl.so.10(0x00007f05e085c000)
如果是手动编译安装，则需要先在官网下载程序包，并添加对openssl的支持，下面是手动编译步骤：
[root@centos68 ~]# yum install -y openssl openssl-devel readline-devel pcre-devellibssl-dev libpcre3
[root@centos68 ~]# wget http://www.haproxy.org/download/1.6/src/haproxy-1.6.13.tar.gz
[root@centos68 ~]# tar xf haproxy-1.6.13.tar.gz ; cd haproxy-1.6.13
[root@centos68 haproxy-1.6.13]# make TARGET=linux2628 USE_PCRE=1USE_OPENSSL=1 USE_ZLIB=1 USE_CRYPT_H=1 USE_LIBCRYPT=1
[root@centos68 haproxy-1.6.13]# ldd $(which haproxy) | grep ssl
libssl.so.10 => /usr/lib64/libssl.so.10 (0x00007f05e085c000)
[root@centos68 haproxy-1.6.13]# make install PREFIX=/usr/local/haproxy
[root@centos68 haproxy-1.6.13]# vi /etc/profile.d/haproxy.sh
#!/bin/bash
export PATH=$PATH:/usr/local/haproxy/sbin/
[root@centos68 haproxy-1.6.13]# source /etc/profile.d/haproxy.sh
创建配置文件目录及拷贝并修改启动脚本：
[root@centos68 haproxy-1.6.13]# mkdir -p /etc/haproxy
[root@centos68 haproxy-1.6.13]# cp examples/haproxy.init/etc/rc.d/init.d/haproxy
[root@centos68 haproxy-1.6.13]# vi /etc/rc.d/init.d/haproxy
BIN=/usr/local/haproxy/sbin/$BASENAME
CFG=/etc/$BASENAME/$BASENAME.cfg
PIDFILE=/var/run/$BASENAME.pid
LOCKFILE=/var/lock/subsys/$BASENAME
至此haproxy已经安装完毕，这里我们根据架构图提供haproxy的配置文件：
[root@centos68 ~]# vi /etc/haproxy/haproxy.cfg
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 40000
user haproxy
group haproxy
daemon
tune.ssl.default-dh-param 2048
# turn on stats unix socket
stats socket/var/lib/haproxy/stats
#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
mode http
log global
option httplog
option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------
frontend http_frontend
bind *:80
bind *:443 ssl crt /etc/haproxy/haproxy.pem # 网站证书文件
mode http
log global
option httpclose
option logasap
option dontlognull
option forwardfor except127.0.0.1 header X-Client if-none
capture request header Host len20
capture request header Refererlen 60
reqadd X-Forwarded-Proto:\ https
#rspadd Via:\ haproxy.example.com
acl url_static path_beg -i/static /p_w_picpaths /javascript /stylesheets
acl url_static path_end -i .jpg.jpeg .png .bmp .gif .css .js
redirect scheme https if !{ ssl_fc } # 全站采用https协议
use_backend static_servers ifurl_static
default_backend dynamic_servers
#---------------------------------------------------------------------
# static backend for serving up p_w_picpaths, stylesheets and such
#---------------------------------------------------------------------
backend static_servers
mode http
balance roundrobin
#option httpchk HEAD /healthchk.html
server static1 192.168.100.64:80 check inter 1000rise 2 fall 4 weight 1 maxconn 6000
server static2 192.168.100.65:80 check inter 1000rise 2 fall 4 weight 1 maxconn 6000
http-request set-headerX-Forwarded-Port %[dst_port]
http-request add-headerX-Forwarded-Proto https if { ssl_fc }
backend dynamic_servers
mode http
balance roundrobin
#cookie dynamic_cookie insert nocache indirect
server https_dynamic1 192.168.200.70:80 checkinter 2000 rise 2 fall 4 weight 1 maxconn 1000
server https_dynamic2 192.168.200.71:80 checkinter 2000 rise 2 fall 4 weight 1 maxconn 1000
http-request set-headerX-Forwarded-Port %[dst_port]
http-request add-headerX-Forwarded-Proto https if { ssl_fc }
listen stats
bind *:9090
stats enable
stats uri /haproxy?stats
stats hide-version
stats auth admin:yourpassword
stats admin if TRUE
②、haproxy.cfg配置说明
haproxy的配置文件位于：/etc/haproxy/haproxy.cfg，该配置文件中的一个重点是添加对https协议的支持，为了实现该目的，需要做如下操作：
我们知道，haproxy代理ssl有三种方式：第一种，haproxy 自身提供ssl 证书，仅是客户端与haproxy之间传输https协议，而haproxy与后端的web server仍然传输http；第二种为SSL透传，haproxy 本身工作于tcp传输层，https由后端server直接处理，但haproxy不对https报文做任何修改，这就意味着后端server失去了对客户端IP、端口及使用协议的记录；第三种，SSL连接在负载均衡器处终止，按需求调整，然后作为新的SSL连接代理到后端服务器。这可能会提供最大的安全性和发送客户端信息的能力。这样做的代价是更多的CPU能耗和稍复杂的配置。实验中我们采用第一种，所以我们需要提供haproxy的ssl证书文件：
因为是实验，所以我们需要生成自签署证书cacert.pem、应用程序haproxy证书haproxy.crt,应用程序haproxy私钥haproxy.key等文件，具体私钥及证书生成步骤这里不再详述。最后将haproxy.crt和haproxy.key合并为一个文件：
[root@centos68 ~]# cd /etc/haproxy
[root@centos68 haproxy]# cat haproxy.crt haproxy.key | tee haproxy.pem
而上面生成的haproxy.pem正是haproxy.cfg所需要的：
bind *:443 ssl crt /etc/haproxy/haproxy.pem
③、keepalived安装与配置
我们需要在前端部署有haproxy的两台server上安装keepalived，其安装过程较为简单，直接使用yum安装即可：
[root@centos68 ~]# yum install -y keepalived
[root@centos68 ~]# rpm -q keepalived
keepalived-1.2.13-5.el6_6.x86_64
haproxy1上的keepalived配置：
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id www.example.com
}
vrrp_script chk_haproxy {
script "killall -0 haproxy&> /dev/null"
interval 1
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 256f6df6
}
virtual_ipaddress {
192.168.0.50/24 dev eth0label eth0:0
}
track_script {
chk_haproxy
}
notify_master"/etc/keepalived/notify.sh master"
notify_backup"/etc/keepalived/notify.sh backup"
notify_fault"/etc/keepalived/notify.sh fault"
}
vrrp_instance VI_2 {
state BACKUP
interface eth0
virtual_router_id 52
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 19afa2c5
}
virtual_ipaddress {
192.168.0.51/24 dev eth0label eth0:1
}
track_script {
chk_haproxy
}
notify_master"/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.shbackup"
notify_fault"/etc/keepalived/notify.sh fault"
}
haproxy2上的keepalived配置：
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id centos66.example.com
}
vrrp_script chk_haproxy {
script "killall -0 haproxy&> /dev/null"
interval 1
weight -20
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 256f6df6
}
virtual_ipaddress {
192.168.0.50/24 dev eth0label eth0:0
}
track_script {
chk_haproxy
}
notify_master"/etc/keepalived/notify.sh master"
notify_backup"/etc/keepalived/notify.sh backup"
notify_fault"/etc/keepalived/notify.sh fault"
}
vrrp_instance VI_2 {
state MASTER
interface eth0
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 19afa2c5
}
virtual_ipaddress {
192.168.0.51/24 dev eth0label eth0:1
}
track_script {
chk_haproxy
}
notify_master "/etc/keepalived/notify.shmaster"
notify_backup"/etc/keepalived/notify.sh backup"
notify_fault"/etc/keepalived/notify.sh fault"
}
消息通知脚本notify.sh：
#!/bin/bash
#Date:2017-10-07
vip=192.168.0.50
contact="root@localhost"
notify() {
mailsubject="`hostname` tobe $1: $vip floating"
mailbody="`date +'%F%H:%M:%S'`: vrrp transition, `hostname` changed to be $1"
echo "$mailbody" | mail-s "$mailsubject" $contact
}
case "$1" in
master)
notify master
exit 0
;;
backup)
notify backup
exit 0
;;
fault)
notify fault
exit 0
;;
*)
echo "Usage: `basename $0`{master|backup|fault}"
exit 1
;;
esac
④、ntpd的安装与配置
由于前端keepalived与后端各server通信需要保证时钟同步，所以我们需要在前端的其中一台主机上安装ntpd服务器，注意本次实验采用的是架构图1，如果是架构图2，那么前端的2台haproxy服务器上均要部署ntpd。
[root@centos66 ~]# yum install -y ntpd
[root@centos66 ~]# vi /etc/ntpd.conf
# For more information about this file, see the man pages
# ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5),ntp_mon(5).
driftfile /var/lib/ntp/drift
# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict ntp1.aliyun.com
restrict ntp2.aliyun.com
restrict ntp3.aliyun.com
restrict ntp4.aliyun.com
restrict ntp5.aliyun.com
# Permit all access over the loopback interface. This could
# be tightened as well, but to do so would effect some of
# the administrative functions.
restrict 127.0.0.1
restrict -6 ::1
restrict 192.168.100.0 mask 255.255.255.0 nomodify
server ntp1.aliyun.com prefer
server ntp2.aliyun.com
server ntp3.aliyun.com
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys
安装完成后启动即可：service ntpd start ;chkconfig ntpd on
后端各server添加crontab任务计划：
[root@www ~]# crontab -e
MAILTO=""
*/10 * * * * /usr/sbin/ntpdate 192.168.100.16 &> /dev/null
这样设置完成后，后端的各server每10分钟就会与前端的ntpd进行一次时钟同步。
⑤、Static Server Group
静态服务器组的组成是由各linux主机上部署nginx来完成，在centos6.8上也可以直接使用yum来安装：
[root@centos66 ~]# yum install -y nginx
然后对后端各主机上的nginx配置文件进行配置：
[root@centos66 ~]# vi /etc/nginx/nginx.conf
# nginx.conf
user nginx;
worker_processes 1;
worker_rlimit_nofile 51200;
pid /var/run/nginx.pid;
events {
worker_connections 51200;
}
http {
include mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status$body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
error_log/var/log/nginx/error.log notice;
sendfile on;
keepalive_timeout 65;
server {
listen 80;
server_name localhost;
location / {
root /var/www/html/phpBB;
index index.html index.htm;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
}
⑥、Dynamic Server Group
在后端各server上需要部署httpd+mariadb+php，在centos7上安装过程比较简单，直接使用yum安装即可，这里不再具体给出各软件安装步骤，我们需要在/etc/httpd/conf.d中添加虚拟主机：
[root@www ~]# cd /etc/httpd/conf.d/
[root@www conf.d]# vi vhosts.conf
<VirtualHost *:80>
DocumentRoot"/var/www/html"
ServerName ftp.example.com
</VirtualHost>
<Directory "/var/www/html/phpBB">
Options Includes ExecCGIFollowSymLinks
AllowOverride None
Require all granted
</Directory>
<VirtualHost *:80>
DocumentRoot "/var/www/html/phpBB"
ServerName www.example.com:80
</VirtualHost>
另外需要将配置文件：/etc/httpd/conf/httpd.conf中的"DocumentRoot"这一行注释掉并修改日志格式：
#DocumentRoot "/var/www/html"
LogFormat "%{X-Client}i%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b\"%{Referer}i\" \"%{User-Agent}i\"" combined
#SetEnvIf Request_URI "^/test.html(/.*)?$" dontlog
#CustomLog "logs/access_log" combined env=!dontlog
⑦、部署phpBB
从phpBB官网下载安装包，将安装包分别拷贝至后端各server：Nginx1,Ngine2,LAMP1,LAMP2上的/var/www/html目录下，解压缩并修改所属用户和组，这里以后端的LAMP1来演示，其它各server上的操作步骤与下面类似：
[root@www ~]# cp phpBB-3.2.0.tar.bz2 /var/www/html
[root@www ~]# cd /var/www/html
[root@www html]# tar xf phpBB-3.2.0.tar.bz2
[root@www html]# ls
phpBB3
[root@www html]# chown -R apache:apache phpBB3
[root@www html]# ln -s phpBB3 phpBB
[root@www html]# chown -R apache:apache phpBB
最后我们在LAMP1和LAMP2上创建数据库
MariaDb[(none)] > create database phpBB
MariaDb[(none)] > grant all privileges on phpBB.* to phpBB@'127.0.0.1'identified by 'yourpassword';
MariaDb[(none)] > flush privileges;
上面创建了phpBB数据库名为：phpBB，数据库用户名：phpBB，密码：yourpassword，这在后续的phpBB页面安装过程中需要。
至此各server配置已经完成，最后就需要我们在浏览器安装phpBB了，在浏览器中输入www.example.com进入安装。