Apache

基本設定

/etc/apache2/sites-available/test.conf :

<VirtualHost *:80>
        ServerName example.com
        ServerAdmin admin@example.com

        DocumentRoot /var/www/test
        <Directory /var/www/test>
                RewriteEngine on
                RewriteCond $1 !^(index\.php|static|crossdomain\.xml|robots\.txt|favicon\.ico)
                RewriteRule ^(.*)$ /index.php/$1 [L]

                Options Indexes FollowSymLinks MultiViews
                AllowOverride All
                Order allow,deny
                allow from all

                ExpiresActive On
                ExpiresByType image/jpg "access plus 10 years"
                ExpiresByType image/jpeg "access plus 10 years"
        </Directory>
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
        LogLevel warn
</VirtualHost>

啟動 conf

sudo a2ensite test

Options

All: 以下諸功能皆有
None: 以下諸功能皆無
Indexes: 自動產生目錄的索引, 將Indexes拿掉, 點選連結目錄就不會秀出目錄來, 會改成403 forbidden的訊息頁面, 如果網站下的 public 下有放 symbolic link 就要將此開啟, 才可以被 access
Includes: 提供 SSI (Server-Side Inclues) 功能, 即使用Apache的指令在html檔中寫程式, 須先載入 includes_module
FollowSymLinks: 遵循符號鏈接, 即能夠連到其它的目錄去執行, 會壓過 SymLinksIfOwnerMatch。
SymLinksIfOwnerMatch: 對符號鏈接及其每一層父資料夾, 都進行權限檢查, 當連結檔本身的owner跟連結目的地的owner不同時拒絕存取, 比 FollowSymLinks 更安全
ExecCGI: 可以執行CGI程式。
MultiViews: 送出多國語言支援的頁面. 此功能必須被明確指定, Options All並不會提供這個功能

打開 Rewrite 模組

cd /etc/apache2
a2enmod
rewrite

設置轉向自訂的404頁面

ErrorDocument 404 /404.php

建立多個virtual host

在/etc/apache2/sites-available建立virtual host, ex: test
sudo a2ensite test
sudo service apache2 restart

設定環境變數

多用在不同的virtual host使得每個都擁有不同的環境變數例如:

不同的virtual host要共用同一個環境變數可以在/etc/apache2/apache2.conf設定

SetEnv BRAND test

各別的virtual host變數可在/etc/apache2/sites-available/ 設定:

  <VirtualHost *:80>
    <Directory /var/www>
    ...
    SetEnv BRAND test[n]
    ...
    </Directory>
  </VirtualHost>

php取得apache環境變數:

  echo getenv('BRAND');

如果網址只指到資料夾，不顯示目前資料夾的檔案列表

<VirtualHost *:80>
    Options -Indexes FollowSymLinks
</VirtualHost>

apache2: Could not reliably determine the server’s fully qualified domain name

$ sudo service apache2 restart
[sudo] password for test:
 * Restarting web server apache2
apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName
... waiting apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName

在/etc/apache2/sites-available/default:

ServerName test.com
<VirtualHost *:80>
    ServerName test.com
    (...略...)
</VirtualHost>

將ServerName宣告為global

或

在/etc/apache2/httpd.conf加上:

ServerName test.com

但apache2.conf要記得Include httpd.conf

不存在的virtual host會自動導向(問題發生在將default不存在)

問題: 原本的default被我刪掉了，而加上兩個virtual host

w1.test.com
w2.test.com

如此一來 w3.test.com 因為不存在，所以會導向w1.test.com

解決方法:

將 /etc/apache2/sites-available/default 加回來, 即可解決此問題, 當不存在的domain會導向到default

後記 :

ServerName變數不可以在每一個virtual host都宣告成global，不然apache會誤判domain

建議ServerName只在default宣告為global變數

apache log

在/etc/apache2/sites-available/default可以找到apache的log存放位置,例如:

ErrorLog ${APACHE_LOG_DIR}/error.log

預設存放在/var/log/apache2/error.log

讓主機上的帳號都有自己的 public 資料夾 - public_html

load /etc/apache2/mods-enabled :

userdir.load

/etc/apache2/mods-enabled/userdir.conf:

 <IfModule mod_userdir.c>
         UserDir public_html
         UserDir disabled root

         <Directory /home/*/public_html>
                 AllowOverride FileInfo AuthConfig Limit Indexes
                 Options MultiViews Indexes FollowSymLinks IncludesNoExec

Indexes、FollowSymLinks

Options -Indexes +FollowSymLinks

-Indexes : 不允許顯示檔案目錄結構
+FollowSymLinks : 允許使用 .htaccess 檔案 override 預設的設定

特定副檔名忽略同源政策

在 <Directory> 裡加上

<FilesMatch "\.(ttf|otf|eot|woff|svg)$">
    <IfModule mod_headers.c>
        Header set Access-Control-Allow-Origin "*"
    </IfModule>
</FilesMatch>

Reduce requests from browser

當瀏覽器第一次讀取圖檔

status : 200 OK

request header:

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:zh-TW,zh;q=0.8,en-US;q=0.6,en;q=0.4
Connection:keep-alive
Host:test.com
User-Agent:Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36

response header:

Accept-Ranges:bytes
Connection:Keep-Alive
Content-Length:45860
Content-Type:image/jpeg
Date:Thu, 11 Jul 2013 08:09:03 GMT
ETag:"bc003e-b324-4e136f4c01a37"
Keep-Alive:timeout=5, max=100
Last-Modified:Thu, 11 Jul 2013 07:00:57 GMT
Server:Apache/2.2.22 (Ubuntu)

內容會有圖檔

第二次讀取讀檔會跟cache要所以

status : 304 Not Modified

request header:

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:zh-TW,zh;q=0.8,en-US;q=0.6,en;q=0.4
Cache-Control:max-age=0
Connection:keep-alive
Host:test.com
If-Modified-Since:Thu, 11 Jul 2013 07:00:57 GMT
If-None-Match:"bc003e-b324-4e136f4c01a37"
User-Agent:Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36

response header:

Connection:Keep-Alive
Date:Thu, 11 Jul 2013 08:09:51 GMT
ETag:"bc003e-b324-4e136f4c01a37"
Keep-Alive:timeout=5, max=100
Server:Apache/2.2.22 (Ubuntu)

內容不會有圖檔，只會送出request然候apache比對ETag及Last-Modified，如果檔案有被修改才是status:200

調整apache設定，當網址一樣時讓瀏覽器連304都不送直接取cache

[1] 打開模組

到 /etc/apache2/mods-available
ls | grep expire 及 ls | grep header 確定有沒有這兩個模組，如果沒有就開啟
Once you install the module, the module will be available in the /etc/apache2/mods-available directory. You can use the a2enmod command to enable a module. You can use the a2dismod command to disable a module. Once you enable the module, the module will be available in the the /etc/apache2/mods-enabled directory.

[2] 在 /etc/apache2/sites-available/default 的<Directory {你的path}> 加上

ExpiresActive On
ExpiresByType image/jpg "access plus 10 years"
ExpiresByType image/jpeg "access plus 10 years"

[3] sudo service apache2 restart

設定後的測試:

[1] 第一次load圖

status : 200 OK

request header:

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:zh-TW,zh;q=0.8,en-US;q=0.6,en;q=0.4
Cache-Control:no-cache
Connection:keep-alive
Host:test.com
Pragma:no-cache
User-Agent:Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36

response header:

Accept-Ranges:bytes
Cache-Control:max-age=315360000
Connection:Keep-Alive
Content-Length:45860
Content-Type:image/jpeg
Date:Thu, 11 Jul 2013 08:11:46 GMT
ETag:"bc003e-b324-4e136f4c01a37"
Expires:Sun, 09 Jul 2023 08:11:46 GMT
Keep-Alive:timeout=5, max=99
Last-Modified:Thu, 11 Jul 2013 07:00:57 GMT
Server:Apache/2.2.22 (Ubuntu)

有加上expire了

[2] 第二次load圖

status : 304 Not Modified

request header:

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:zh-TW,zh;q=0.8,en-US;q=0.6,en;q=0.4
Cache-Control:max-age=0
Connection:keep-alive
Host:test.com
If-Modified-Since:Thu, 11 Jul 2013 07:00:57 GMT
If-None-Match:"bc003e-b324-4e136f4c01a37"
User-Agent:Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36

response header:

Cache-Control:max-age=315360000
Connection:Keep-Alive
Date:Thu, 11 Jul 2013 08:25:53 GMT
ETag:"bc003e-b324-4e136f4c01a37"
Expires:Sun, 09 Jul 2023 08:25:53 GMT
Keep-Alive:timeout=5, max=99
Server:Apache/2.2.22 (Ubuntu)

[3] 當從外面直接連進來後會直接從cache拿了

Request URL:http://test.com/static/a/ce/ce9600a437486fbfd9b13856f2e1c55f.jpg?1373516123
Request Method:GET
Status Code:200 OK (from cache)
Query String Parametersview sourceview URL encoded
1373516123:

並不會有request header及response header，因為根本沒送request chrome也會顯示是 (from cache)

大頭貼檔名後加上從DB取的timestamp(ex: avatar.jpg?1373530721)，當更新大頭貼時要更新DB的欄位(紀錄修改時間)，才能讓瀏覽器判斷是否是修改過的圖

Conclusion

快取機制還是要看瀏覽器自已的實作, 如果到已造訪過的網站, chrome第一次可能拿快取的圖片, 但reload後chrome還是會去問一次得到304才去拿cache的檔案, 所以快取機制沒有一定, 或許chrome 再下一版又換方法了

ref : 夯哥