[root@varnish ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo 
#下載阿里鏡像站的repo文件
[root@varnish ~]# yum -y install libedit-devel pcre-devel python-docutils  #安裝依賴包
[root@varnish ~]# cd /usr/src    #切換至指定目錄
[root@varnish src]# rz   #上傳我提供的varnish源碼包
[root@varnish src]# tar zxf varnish-4.0.3.tar.gz     #解包
[root@varnish src]# cd varnish-4.0.3/      #進(jìn)入解壓后的目錄
[root@varnish varnish-4.0.3]# ./configure && make && make install    #編譯安裝
[root@varnish varnish-4.0.3]# cp etc/example.vcl /usr/local/var/varnish/   #復(fù)制模板到指定路徑
[root@varnish varnish-4.0.3]# cd !$    #切換到varnish安裝目錄下
[root@varnish varnish]# vim example.vcl     #編輯其模板配置文件，根據(jù)自己所需功能，編寫以下內(nèi)容：
#
# This is an example VCL file for Varnish.
#
# It does not do anything by default, delegating control to the
# builtin VCL. The builtin VCL is called when there is no explicit
# return statement.
#
# See the VCL chapters in the Users Guide at https://www.varnish-cache.org/docs/
# and http://varnish-cache.org/trac/wiki/VCLExamples for more examples.

# Marker to tell the VCL compiler that this VCL has been adapted to the
# new 4.0 format.
vcl 4.0;
import directors;
import std;
# Default backend definition. Set this to point to your content server.
probe backend_healthcheck {
.url="/"; #訪問后端服務(wù)器根路徑
.interval = 5s;  #請(qǐng)求時(shí)間間隔
.timeout = 1s;  #請(qǐng)求超時(shí)時(shí)間
.window = 5;  #指定輪詢次數(shù)5次
.threshold = 3;  #如果出現(xiàn)3次失敗則表示后端服務(wù)器宕機(jī)
}
backend web1 {  #定義后端服務(wù)器
.host = "192.168.20.4"; #要轉(zhuǎn)向主機(jī)（即后端主機(jī)）的 IP 或域名
.port = "80"; #指定后端服務(wù)器的端口號(hào)
.probe = backend_healthcheck; #健康檢查調(diào)用backend_healthcheck定義的內(nèi)容
}
backend web2 {
.host = "192.168.20.3";   
.port = "80";
.probe = backend_healthcheck;
}
acl purgers { #定義訪問控制列表
    "127.0.0.1";
    "localhost";
    "192.168.20.0/24";
    !"192.168.20.4";
}
sub vcl_init {   #調(diào)用 vcl_init 初始化子程序創(chuàng)建后端主機(jī)組，即 directors
    new web_cluster=directors.round_robin(); #使用 new 關(guān)鍵字創(chuàng)建 drector 對(duì)象,使用 round_robin(輪詢) 算法
    web_cluster.add_backend(web1);  #添加后端服務(wù)器節(jié)點(diǎn)
    web_cluster.add_backend(web2);
}
sub vcl_recv {
    set req.backend_hint = web_cluster.backend(); #指定請(qǐng)求的后端節(jié)點(diǎn)web_cluster定義的后端節(jié)點(diǎn)
    if (req.method == "PURGE") {  #判斷客戶端的請(qǐng)求頭部是否是PURGE
        if (!client.ip ~ purgers) {  #如果是，再判斷客戶端的IP地址是不是在ACL訪問控制列表中.
            return (synth(405, "Not Allowed.")); #如果不是，返回給客戶端405狀態(tài)碼并且返回定義的頁(yè)面.
    }
    return (purge);  #如果是ACL定義的，則交給purge處理.
}
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") {   #判斷客戶端的請(qǐng)求類型
        return (pipe);
    }
if (req.method != "GET" && req.method != "HEAD") {
    return (pass);   #如果不是GET及HEAD則交給pass.
}
if (req.url ~ "\.(php|asp|aspx|jsp|do|ashx|shtml)($|\?)") {
    return (pass);  #當(dāng)客戶端訪問的是.php等結(jié)尾的交給pass處理.
}
if (req.http.Authorization) {
    return (pass);  #當(dāng)客戶端請(qǐng)求的頁(yè)面類型是需要認(rèn)證的，交給pass處理
}
if (req.http.Accept-Encoding) {
    if (req.url ~ "\.(bmp|png|gif|jpg|jpeg|ico|gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)$") {
    unset req.http.Accept-Encoding;  #取消客戶端接收的壓縮類型
    } elseif (req.http.Accept-Encoding ~ "gzip") {
        set req.http.Accept-Encoding = "gzip"; #如果有g(shù)zip類型，標(biāo)記gzip類型.
    } elseif (req.http.Accept-Encoding ~ "deflate") {
        set req.http.Accept-Encoding = "deflate";
    } else {
    unset req.http.Accept-Encoding; #其他未定義的頁(yè)面也取消客戶但接收的壓縮類型.
    }
   }
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; #取消客戶端的cookie值.
    return (hash);  #將請(qǐng)求轉(zhuǎn)發(fā)給hash子程序，也就是查看本地緩存.
}
if (req.restarts == 0) { #判斷客戶端是不是第一次請(qǐng)求
    if (req.http.X-Forwarded-For) {   #如果是第一次請(qǐng)求，設(shè)置獲取客戶端的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);  #查看客戶端請(qǐng)求的頁(yè)面，并且進(jìn)行hash
    if (req.http.host) {
        hash_data(req.http.host); #設(shè)置客戶端的主機(jī)
    } else {
        hash_data(server.ip);  #設(shè)置服務(wù)器的IP
    }
    return (lookup);
}
sub vcl_hit {
    if (req.method == "PURGE") {  #如果是HIT并且當(dāng)客戶端請(qǐng)求的類型是PURGE返回的200的狀態(tài)碼，并返回相應(yīng)頁(yè)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"; #設(shè)置http頭部X-Cache =hit
        set resp.http.X-Cache-Hits = obj.hits; #返回命令的次數(shù)
    } else {
    set resp.http.X-Cache = "MISS";
    }
    unset resp.http.X-Powered-By; #取消顯示web版本
    unset resp.http.Server;  #取消顯示varnish服務(wù)
    unset resp.http.X-Drupal-Cache;  #取消顯示緩存的框架
    unset resp.http.Via;  #取消顯示文件內(nèi)容來源
    unset resp.http.Link; #取消顯示HTML的超鏈接地址
    unset resp.http.X-Varnish; #取消顯示varnish的id
    set resp.http.xx_restarts_count = req.restarts;  #設(shè)置客戶端請(qǐng)求的次數(shù)
    set resp.http.xx_Age = resp.http.Age;  #顯示緩存文件的時(shí)長(zhǎng)
    #set resp.http.hit_count = obj.hits;  #顯示緩存命中的次數(shù)
    #unset resp.http.Age;
    return (deliver);
}
sub vcl_pass {
    return (fetch);  #將后端服務(wù)器返回的數(shù)據(jù)緩存到本地
}
sub vcl_backend_response {
    set beresp.grace = 5m;  #緩存額外寬限時(shí)間
    if (beresp.status == 499 || beresp.status == 404 || beresp.status == 502) {
        set beresp.uncacheable = true;  #當(dāng)后端服務(wù)器相應(yīng)狀態(tài)碼是449等，不緩存
    }
    if (bereq.url ~ "\.(php|jsp)(\?|$)") {
        set beresp.uncacheable = true; #當(dāng)是PHP的頁(yè)面不緩存
    } else {
        if (bereq.url ~ "\.(css|js|html|htm|bmp|png|gif|jpg|jpeg|ico)($|\?)") {
        set beresp.ttl = 15m; #當(dāng)是上面結(jié)尾的，緩存15分鐘
        unset beresp.http.Set-Cookie;
        } elseif (bereq.url ~ "\.(gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)($|\?)") {
            set beresp.ttl = 30m; #緩存30分鐘
            unset beresp.http.Set-Cookie;
        } else {
            set beresp.ttl = 10m; #生存時(shí)間10分鐘
            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); #如果狀態(tài)碼是上述其中之一，則重新請(qǐng)求
    }
}
sub vcl_fini {
    return (ok);
}
#編輯完成后，保存退出后即可。
[root@varnish varnish]# varnishd -f /usr/local/var/varnish/example.vcl -s malloc,200M -a 0.0.0.0:80
#啟動(dòng)varnish服務(wù)，監(jiān)聽本機(jī)所有IP的80端口，-f為指定vcl文件，-s是指定用來存放緩存的容量
[root@varnish ~]# varnishlog  #varnish啟動(dòng)后，可以執(zhí)行此命令查看其日志。

[root@localhost ~]# curl -X "PURGE" 192.168.20.5    #清除varnish的緩存

vcl 4.0;
import directors;
import std;
probe backend_healthcheck {
.url="/"; 
.interval = 5s;
.timeout = 1s;
.window = 5; 
.threshold = 3; 
}
backend web1 { 
.host = "192.168.20.4"; 
.port = "80"; 
.probe = backend_healthcheck; 
}
backend web2 {
.host = "192.168.20.3";   
.port = "80";
.probe = backend_healthcheck;
}
acl purgers { 
    "127.0.0.1";
    "localhost";
    "192.168.20.0/24";
    !"192.168.20.4";
}
sub vcl_init { 
    new web_cluster=directors.round_robin();
    web_cluster.add_backend(web1); 
    web_cluster.add_backend(web2);
}
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)($|\?)") {
    return (pass); 
}
if (req.http.Authorization) {
    return (pass); 
}
if (req.http.Accept-Encoding) {
    if (req.url ~ "\.(bmp|png|gif|jpg|jpeg|ico|gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)$") {
    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_pass {
    return (fetch); 
}
sub vcl_backend_response {
    set beresp.grace = 5m; 
    if (beresp.status == 499 || beresp.status == 404 || beresp.status == 502) {
        set beresp.uncacheable = true;
    }
    if (bereq.url ~ "\.(php|jsp)(\?|$)") {
        set beresp.uncacheable = true; 
    } else {
        if (bereq.url ~ "\.(css|js|html|htm|bmp|png|gif|jpg|jpeg|ico)($|\?)") {
        set beresp.ttl = 15m; 
        unset beresp.http.Set-Cookie;
        } elseif (bereq.url ~ "\.(gz|tgz|bz2|tbz|zip|rar|mp3|mp4|ogg|swf|flv)($|\?)") {
            set beresp.ttl = 30m;
            unset beresp.http.Set-Cookie;
        } else {
            set beresp.ttl = 10m;
            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); 
    }
}
sub vcl_fini {
    return (ok);
}

import directors;
probe backend_healthcheck {
    .url = "/";
    .timeout = 1s;
    .interval = 5s;
    .window = 5;
    .threshold = 3;
}
backend web1 {
    .host = "192.168.20.3";
    .port = "80";
    .probe = backend_healthcheck;
}
backend web2 {
    .host = "192.168.20.4";
    .port = "80";
    .probe = backend_healthcheck;
}
sub vcl_init {
    new web_cluster = directors.round_robin();
    web_cluster.add_backend(web1);
    web_cluster.add_backend(web2);
}
sub vcl_recv {
    set req.backend_hint = web_cluster.backend();
}