Question

出于CDN失效的目的，我需要在网站的URL的路径元素中添加前缀。每当发布新版本的资产时，都会更改此信息。

然后使用mod_rewrite将URL重写为：http://example.com/cdn/20111030/images/image.jpg到http://example.com/images/image.jpg，这是资产实际所在的位置。

我想在响应中添加长期到期标题（至少3个月）（对于文件系统中实际不存在的第一个URL）。有谁知道怎么做？

Answer 1

如果您在Apache配置中为自己的解决方案添加RewriteEngine / Rule，则可以正确选择Location并在/ cdn调用上提供Expires / Cache-Control，并且不为非cdn提供它们电话，稍作改动：

    # in apache config
    RewriteEngine On
    RewriteRule ^/cdn/[^/]*/(.*) /$1 [L]

    <Location "/cdn">
      Header unset ETag
      FileETag None
      ExpiresActive on
      ExpiresDefault "access plus 1 year"
    </Location>

我无法在Apache配置中看到这个问题。

Answer 2

来自http://drupal.org/node/974350#comment-5305368
这些规则为480周，但您可以相应地调整时间。

<IfModule mod_rewrite.c>
  RewriteEngine on
  <IfModule mod_headers.c>
    # Transform /cdn/***/ to /
    RewriteCond %{REQUEST_URI} ^/cdn/([0-9a-zA-Z])*/(.+)$
    RewriteRule .* /%2 [L,E=CDN:1]
    # Apache will change CDN to REDIRECT_CDN.

    # Set a far future Cache-Control header (480 weeks), which prevents
    # intermediate caches from transforming the data and allows any
    # intermediate cache to cache it, since it's marked as a public resource.
    Header set Cache-Control "max-age=290304000, no-transform, public" env=REDIRECT_CDN

    # Set a far future Expires header. The maximum UNIX timestamp is somewhere
    # in 2038. Set it to a date in 2037, just to be safe.
    Header set Expires "Tue, 20 Jan 2037 04:20:42 GMT" env=REDIRECT_CDN

    # Pretend the file was last modified a long time ago in the past, this will
    # prevent browsers that don't support Cache-Control nor Expires headers to
    # still request a new version too soon (these browsers calculate a
    # heuristic to determine when to request a new version, based on the last
    # time the resource has been modified).
    # Also see http://code.google.com/speed/page-speed/docs/caching.html.
    Header set Last-Modified "Wed, 20 Jan 1988 04:20:42 GMT" env=REDIRECT_CDN

    # Do not use etags for cache validation.
    Header unset ETag env=REDIRECT_CDN
  </IfModule>
</IfModule>

另请参阅AdvAgg rules，因为这些处理服务器没有安装mod_headers或mod_expires。它使用FilesMatch指令; advagg文件有一个相当独特的文件名，因此我可以这样做。 AdvAgg后备在这种情况下不起作用，因为mod_expires不能使用环境变量; FileETag也不能。从我所看到的情况来看，mod_headers是在apache中设定远期未来时间的理想方式。

Answer 3

解决方案可以是将Expires应用于所有资产，使用mod_headers从非cdn版本中删除标题，例如：

 RewriteEngine on
 RewriteRule ^cdn/([0-9a-z])*/(.*) /$2 [L,E=cdn:1]

 ExpiresActive on
 ExpiresDefault "access plus 1 year"
 Header unset Expires env=!cdn
 Header unset Cache-Control env=!cdn

对于网站的根源来说，这有点过分，但如果仅应用于资产，则不会成为问题。

使用Apache为文件系统中不存在的路径添加到期标头

3 个答案: