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Accepted
KM.
Asked: 2012-01-26 19:02:09 +0800 CST

Adding Hostname as a Custom Varnish Header

  • 772

I've several varnish cache servers (v2.1), and I'm looking to add the hostname in the headers in the response from varnish -- so I know which server is (or not) serving cached pages. Upon googling, I found this snippet, but it gives errors:

sub vcl_deliver {
  if (obj.hits > 0) {
    set resp.http.X-MH-Cache ="HIT " obj.hits " "*
    server.hostname* " " resp.http.Age;
  } else {
    set resp.http.X-MH-Cache ="MISS " *server.hostname* ""
  }
}

I am not tied to this snippet per se. Ideally, I would like to set hostname in the event of a miss or a hit.

I am fairly new to vcl files, so any guidance and assistance would be much appreciated. Many thanks!

KM

configuration varnish

2 Answers

  1. Best Answer

    Stumbled upon this by chance (isn't it always that way?): https://www.varnish-cache.org/trac/wiki/VCLExampleHitMissHeader -- exactly what I was looking for.

    • 0

  2. More likely the error was due to the star signs, and missing plus signs when building up the "X-MH-Cache response header:

    Unknown token '*' when looking for STRING

    The working vcl code snippet looks like this:

    vcl 4.1;
import std;
sub vcl_deliver {
  if (obj.hits > 0) {
    set resp.http.X-MH-Cache = "HIT: " + obj.hits + " *" + server.hostname + "* Age: " + resp.http.Age;
  } else {
    set resp.http.X-MH-Cache = "MISS *" + server.hostname + "*";
  }
}

    A snapshot (January 2nd, 2012) to the URL from of the answer (January 27th, 2012) can be found on the Internet Archive site here: https://web.archive.org/web/20120309095329/https://www.varnish-cache.org/trac/wiki/VCLExampleHitMissHeader

    • 0