玩转企业常见应用与服务系列（九）：开源HTTP加速器 Varnish 详解

yum -y install autoconf automake libedit-devel libtool ncurses-devel pcre-devel  pkgconfig python-docutils python-sphin

tar zxf varnish-4.0.3.tar.gz 
[root@localhost ~]# cd varnish-4.0.3/
[root@localhost varnish-4.0.3]# ./configure && make && make install
[root@localhost varnish-4.0.3]# cp etc/example.vcl /usr/local/var/varnish

vim /usr/local/var/varnish/example.vcl

vcl 4.0;
import directors;
import std;
backend default {
    .host = "127.0.0.1";
    .port = "80";
}
probe backend_healthcheck {
        .url="/";
        .interval = 5s;
        .timeout = 1s;
        .window = 5;
        .threshold = 3;
}
backend web1 {
        .host = "192.168.148.132";
        .port = "80";
        .probe = backend_healthcheck;
}
backend web2 {
        .host = "192.168.148.133";
        .port = "80";
        .probe = backend_healthcheck;
}
acl purgers {
        "127.0.0.1";
        "localhost";
        "192.168.148.0/24";
        !"192.168.148.133";
}
sub vcl_init  {
        new  web_cluster=directors.round_robin();
        web_cluster.add_backend(web1);
        web_cluster.add_backend(web2);
}
//把原来的全部删除添加如下
sub vcl_recv {
        set req.backend_hint = web_cluster.backend();
        if (req.method == "PURGE") {
                if (!client.ip ~ purgers) {
                        return (synth(405, "Not Allowed."));
        }
        return (purge);
}
if (req.method != "GET" &&
        req.method != "HEAD" &&
        req.method != "PUT" &&
        req.method != "POST" &&
        req.method != "TRACE" &&
        req.method != "OPTIONS" &&
        req.method != "PATCH" &&
        req.method != "DELETE") {
                return (pipe);
        }
if (req.method != "GET" && req.method != "HEAD") {
        return (pass);
}
if (req.url ~ "\.(php|asp|aspx|jsp|do|ashx|shtml)($|\?)") {
        return (pass);
}
if (req.http.Accept-Encoding) {
        if  (req.url  ~ "\.(bmp|png|gif|jpg|jpeg|ico|gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)$") {
        unset req.http.Accept-Encoding;
} elseif (req.http.Accept-Encoding ~ "gzip") {
                set req.http.Accept-Encoding = "gzip";
        } elseif (req.http.Accept-Encoding ~ "deflate") {
                set req.http.Accept-Encoding = "deflate";
        } else {
        unset req.http.Accept-Encoding;
        }
     }
if  (req.url  ~ "\.(css|js|html|htm|bmp|png|gif|jpg|jpeg|ico|gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)($|\?)") {
        unset req.http.cookie;
        return (hash);
}
if (req.restarts == 0) {
        if (req.http.X-Forwarded-For) {
                set req.http.X-Forwarded-For = req.http.X-Forwarded-For + ", " + client.ip;
        } else {
       set req.http.X-Forwarded-For = client.ip;
        }
}
return (hash);
}
sub vcl_hash {
        hash_data(req.url);
        if (req.http.host) {
        hash_data(req.http.host);
        } else {
                hash_data(server.ip);
        }
        return (lookup);
}
sub vcl_hit {
        if (req.method == "PURGE") {
                return (synth(200, "Purged."));
        }
        return (deliver);
}
sub vcl_miss {
    if (req.method == "PURGE") {
                return (synth(404, "Purged."));
        }
        return (fetch);
}
sub vcl_deliver {
        if (obj.hits > 0) {
                set resp.http.CXK = "HIT-from-varnish";
                set resp.http.X-Cache-Hits = obj.hits;
        } else {
        set resp.http.X-Cache = "MISS";
        }
        unset resp.http.X-Powered-By;
        unset resp.http.Server;
        unset resp.http.X-Drupal-Cache;
        unset resp.http.Via;
        unset resp.http.Link;
        unset resp.http.X-Varnish;
        set resp.http.xx_restarts_count = req.restarts;
        set resp.http.xx_Age = resp.http.Age;
        set resp.http.hit_count = obj.hits;
                unset resp.http.Age;
                        return (deliver);
                        }
 
sub vcl_purge {
        return (synth(200,"success"));
}
sub vcl_backend_error {
        if (beresp.status == 500 ||
                beresp.status == 501 ||
                beresp.status == 502 ||
                beresp.status == 503 ||
                beresp.status == 504) {
                return (retry);
        }
}
sub vcl_fini {
        return (ok);
}

varnishd -f /usr/local/var/varnish/example.vcl -s malloc,200M -a 0.0.0.0:80

[root@localhost ~]# yum -y install httpd
[root@localhost ~]# echo aaa > /var/www/html/index.html
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# systemctl start httpd

[root@localhost ~]# yum -y install httpd
[root@localhost ~]# echo bbb > /var/www/html/index.html
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# systemctl start httpd

backend后端配置  #给varnish添加反代服务器节点，最少配置一个;
ACL配置  #给varnish添加访问控制列表，可以指定这些列表访问或禁止访问;
probes配置  #给varnish添加探测后端服务器是否正常的规则，方便切换或禁止对应后端服务器;
directors配置  #给varnish添加负载均衡模式管理多个后端服务器;
核心子程序配置  #给varnish添加后端服务器切换、请求缓存、访问控制、错误处理等规则;

vcl 4.0;
import directors;
import std;
# Default backend definition. Set this to point to your content server.
probe backend_healthcheck {
        .url="/"; #访问后端服务器根路径
        .interval = 5s;   #请求时间间隔
        .timeout = 1s;   #请求超时时间
        .window = 5;    #指定轮询次数5次
        .threshold = 3;   #如果出现3次失败则表示后端服务器异常
}
backend web1 {    #定义后端服务器
        .host = "192.168.1.7";  #要转向主机（即后端主机）的 IP 或域名
        .port = "80";  #指定后端服务器的端口号
        .probe = backend_healthcheck;  #健康检查调用backend_healthcheck定义的内容
}
backend web2 {
        .host = "192.168.1.8";
        .port = "80";
        .probe = backend_healthcheck;
}
acl purgers { #定义访问控制列表
        "127.0.0.1";
        "localhost";
        "192.168.1.0/24";
        !"192.168.1.8";
}
sub vcl_init  {     #调用 vcl_init 初始化子程序创建后端主机组，即 directors
        new  web_cluster=directors.round_robin(); #使用 new 关键字创建 drector 对象,使用 round_robin(轮询) 算法
        web_cluster.add_backend(web1);   #添加后端服务器节点
        web_cluster.add_backend(web2);
}
sub vcl_recv {
        set req.backend_hint = web_cluster.backend(); #指定请求的后端节点web_cluster定义的后端节点
        if (req.method == "PURGE") {   #判断客户端的请求头部是否是PURGE
                if (!client.ip ~ purgers) {   #如果是，再判断客户端的IP地址是不是在ACL访问控制列表中.
                        return (synth(405, "Not Allowed."));  #如果不是，返回给客户端405状态码并且返回定义的页面.
        }
        return (purge);   #如果是ACL定义的，则交给purge处理.
}
if (req.method != "GET" &&
        req.method != "HEAD" &&
        req.method != "PUT" &&
        req.method != "POST" &&
        req.method != "TRACE" &&
        req.method != "OPTIONS" &&
        req.method != "PATCH" &&
        req.method != "DELETE") {      #判断客户端的请求类型
                return (pipe);
        }
if (req.method != "GET" && req.method != "HEAD") {
        return (pass);      #如果不是GET及HEAD则交给pass.
}
if (req.url ~ "\.(php|asp|aspx|jsp|do|ashx|shtml)($|\?)") {
        return (pass);   #当客户端访问的是.php等结尾的交给pass处理.
}
if (req.http.Accept-Encoding) {
        if  (req.url  ~ "\.(bmp|png|gif|jpg|jpeg|ico|gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)$") {
        unset req.http.Accept-Encoding;   #取消客户端接收的压缩类型
        } elseif (req.http.Accept-Encoding ~ "gzip") {
                set req.http.Accept-Encoding = "gzip";  #如果有gzip类型，标记gzip类型.
        } elseif (req.http.Accept-Encoding ~ "deflate") {
                set req.http.Accept-Encoding = "deflate";
        } else {
        unset req.http.Accept-Encoding;  #其他未定义的页面也取消客户但接收的压缩类型.
        }
     }
if  (req.url  ~ "\.(css|js|html|htm|bmp|png|gif|jpg|jpeg|ico|gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)($|\?)") {
        unset req.http.cookie;  #取消客户端的cookie值.
        return (hash);    #将请求转发给hash子程序，也就是查看本地缓存.
}
if (req.restarts == 0) {  #判断客户端是不是第一次请求
        if (req.http.X-Forwarded-For) {     #如果是第一次请求，设置获取客户端的IP地址.
                set req.http.X-Forwarded-For = req.http.X-Forwarded-For + ", " + client.ip;
        } else {
       set req.http.X-Forwarded-For = client.ip;
        }
}
return (hash);
}
sub vcl_hash {
        hash_data(req.url);   #查看客户端请求的页面，并且进行hash
        if (req.http.host) {
                hash_data(req.http.host);  #设置客户端的主机
        } else {
                hash_data(server.ip);    #设置服务器的IP
        }
        return (lookup);
}
sub vcl_hit {
        if (req.method == "PURGE") {   #如果是HIT并且当客户端请求的类型是PURGE返回的200的状态码，并返回相应页面.
                return (synth(200, "Purged."));
        }
        return (deliver);
}
sub vcl_miss {
    if (req.method == "PURGE") {
                return (synth(404, "Purged."));   #如果是miss返回404
        }
        return (fetch);
}
sub vcl_deliver {
        if (obj.hits > 0) {
                set resp.http.CXK = "HIT-from-varnish"; #设置http头部X-Cache =hit
                set resp.http.X-Cache-Hits = obj.hits;  #返回命令的次数
        } else {
        set resp.http.X-Cache = "MISS";
        }
        unset resp.http.X-Powered-By;  #取消显示web版本
        unset resp.http.Server;    #取消显示varnish服务
        unset resp.http.X-Drupal-Cache;   #取消显示缓存的框架
        unset resp.http.Via;    #取消显示文件内容来源
        unset resp.http.Link;  #取消显示HTML的超链接地址
        unset resp.http.X-Varnish;  #取消显示varnish的id
        set resp.http.xx_restarts_count = req.restarts;   #设置客户端请求的次数
        set resp.http.xx_Age = resp.http.Age;   #显示缓存文件的时长
        #set resp.http.hit_count = obj.hits;   #显示缓存命中的次数
        #unset resp.http.Age;
        return (deliver);
}
sub vcl_pass {
        return (fetch);   #将后端服务器返回的数据缓存到本地
}
sub vcl_backend_response {
        set beresp.grace = 5m;   #缓存额外宽限时间
        if (beresp.status == 499 || beresp.status == 404 || beresp.status == 502) {
                set beresp.uncacheable = true;   #当后端服务器相应状态码是449等，不缓存
        }
        if (bereq.url ~ "\.(php|jsp)(\?|$)") {
                set beresp.uncacheable = true;  #当是PHP的页面不缓存
        } else {
                if (bereq.url ~ "\.(css|js|html|htm|bmp|png|gif|jpg|jpeg|ico)($|\?)") {
                set beresp.ttl = 15m;  #当是上面结尾的，缓存15分钟
                unset beresp.http.Set-Cookie;
                } elseif (bereq.url ~ "\.(gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)($|\?)") {
                        set beresp.ttl = 30m; #缓存30分钟
                        unset beresp.http.Set-Cookie;
                } else {
                        set beresp.ttl = 10m;  #生存时间10分钟
                        unset beresp.http.Set-Cookie;
                }
        }
        return (deliver);
}
sub vcl_purge {
        return (synth(200,"success"));
}
sub vcl_backend_error {
        if (beresp.status == 500 ||
                beresp.status == 501 ||
                beresp.status == 502 ||
                beresp.status == 503 ||
                beresp.status == 504) {
                return (retry);  #如果状态码是上述其中之一，则重新请求
        }
}
sub vcl_fini {
        return (ok);
}

[root@varnish varnish]# /usr/local/sbin/varnishd -f /usr/local/var/varnish/default.vcl -s malloc,200M -T 127.0.0.1:2000 -a 0.0.0.0:80
#此处的80端口是varnish工作的监听端口;

-f /usr/local/varnish-3.0.2/etc/default.vcl
#这个–f选项指定varnishd使用哪个配置文件;

-s malloc,200M
#这个–s选项用来确定varnish使用的存储类型和存储容量,使用的是malloc类型(malloc是一个C函数,用于分配内存空间)200M定义多少内存;

-T 127.0.0.1:2000
#Varnish有一个基于文本的管理接口,启动它可以在不停止varnish的情况下来管理varnish。可以指定管理软件监听哪个接口。当然不能让所有人都能访问varnish管理接口,因为他们可以很轻松的通过访问varnish管理接口来获得root访问权限。推荐只让它监听本机端口;

-a 0.0.0.0:80
#varnish监听所有IP发给80端口的http请求,正常网站对外http访问端口为80;

[root@varnish varnish]# yum -y install telnet
[root@varnish varnish]# telnet 127.0.0.1 2000
ban.url test.php  #清除该url缓存
ban.url .*  #清除所有的
[root@varnish varnish]# varnishadm -T 127.0.0.1:2000 ban "req.http.host ~ www.abc.com$ && req.url ~ /image/test.jpg"
#www.abc.com为被清除的域名;
#/image/test.jpg为被清除的url地址列表;

清除所有缓存
[root@varnish varnish]# varnishadm -T 127.0.0.1:2000 ban.url *$

清除image目录下所有缓存
[root@varnish varnish]# varnishadm -T 127.0.0.1:2000 ban.url test.php.url /images

#查看客户端请求的url次数;
[root@varnish varnish]# varnishtop -i rxurl

#查看请求后端服务器的url次数;
[root@varnish varnish]# varnishtop -i txurl

#查看接收到的头信息中有多少次包含Accept-Encoding;
[root@varnish varnish]# varnishtop -i Rxheader -I Accept-Encoding

[root@varnish varnish]# varnishhist

[root@varnish varnish]# varnishsizes

[root@varnish varnish]# varnishstat

[root@varnish varnish]# varnishlog

[root@varnish varnish]# varnishncsa -w /var/lib/varnish/varnish.log  
#将varnishlog保存在一个文本文件里;