Varnish:如何根据特定cookie的值分别缓存页面

Question

我管理的站点只有一个cookie，我们必须使用它，但它始终是9个值中的一个(包括没有值)。我想在我们的应用服务器前面使用varnish，用varnish根据cookie值分别缓存每个页面的一个版本。

因此，如果我们有页面/page1，Varnish应该单独管理/page1的副本和Cookie值a、b、c、d等。

假设我们在Varnish服务器上有足够的内存来存储包含所有cookie组合的所有页面。

我们已经尝试了许多VCL设置，但不能准确地弄清楚如何使其工作。Varnish还需要将特定的cookie发送到我们的应用服务器，以便我们的应用程序知道要发送回哪些内容。

提前感谢！

Answer 1

实际上，要实现这一点非常简单，您应该添加一个自定义vcl_hash

sub vcl_hash {
  #...
  /* Hash cookie data */
  # As requests with same URL and host can produce diferent results when issued with  different cookies,
  # we need to store items hashed with the associated cookies. Note that cookies are already sanitized when we reach this point.
  if (req.http.Cookie) {
    /* Include cookie in cache hash */
    hash_data(req.http.Cookie);
  }
  #...
}

使用此代码，varnish将为每个Cookie值存储不同的cookie ...但我建议你也在vcl_recv上清理你的cookie，这是一段摘录，其中包含了针对Drupal站点的cookie清理：

sub vcl_recv {
  #...
  # Remove all cookies that backend doesn't need to know about.
  # See https://www.varnish-cache.org/trac/wiki/VCLExampleRemovingSomeCookies
  if (req.http.Cookie) {
    /* Warning: Not a pretty solution */
    /* Prefix header containing cookies with ';' */
    set req.http.Cookie = ";" + req.http.Cookie;
    /* Remove any spaces after ';' in header containing cookies */
    set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
    /* Prefix cookies we want to preserve with one space */
    /* 'S{1,2}ESS[a-z0-9]+' is the regular expression matching a Drupal session cookie ({1,2} added for HTTPS support) */
    /* 'NO_CACHE' is usually set after a POST request to make sure issuing user see the results of his post */
    /* Keep in mind we should add here any cookie that should reach the backend such as splahs avoiding cookies */
    set req.http.Cookie = regsuball(req.http.Cookie, ";(S{1,2}ESS[a-z0-9]+|NO_CACHE|OATMEAL|CHOCOLATECHIP)=", "; \1=");
    /* Remove from the header any single Cookie not prefixed with a space until next ';' separator */
    set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
    /* Remove any '; ' at the start or the end of the header */
    set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");

    if (req.http.Cookie == "") {
      /* If there are no remaining cookies, remove the cookie header. */
      unset req.http.Cookie;
    }
  }
  #...
  return(hash);
  #...
}

1

Answer 2

在最初提出这个问题的时候，NITEMAN提供了一个很好的答案。然而，中间的时间跨度导致了官方支持的VMOD，使过滤不需要的cookie变得更容易和更干净。可在以下位置找到：https://github.com/varnish/varnish-modules

来自自述文件中的示例(稍作调整)：

import cookie;

sub vcl_recv {
        cookie.parse(req.http.cookie);
        cookie.filter_except("SESSIONID,PHPSESSID");
        set req.http.cookie = cookie.get_string();
        # Only SESSIONID and PHPSESSID are left in req.http.cookie at this point.
        # ...
        return (hash);
        # ...
}