Stripping out select querystring attribute/value pairs so varnish will not vary cache by them

Question

My goal is to \"whitelist\" certain querystring attributes and their values so varnish will not vary cache between the urls.

Example:

Url 1: http:/         


        

Answer 1

There's something wrong with the RegEx.
I changed the RegExes used in both regsub calls:

sub normalize_req_url {
    # Clean up root URL
    if (req.url ~ "^/(?:\?.*)?$") {
        set req.url = "/";
    }

    # Strip out Google Analytics campaign variables
    # They are only needed by the javascript running on the page
    # utm_source, utm_medium, utm_campaign, gclid, ...
    if (req.url ~ "(\?|&)(gclid|cx|ie|cof|siteurl|zanpid|origin|utm_[a-z]+|mr:[A-z]+)=") {
        set req.url = regsuball(req.url, "(gclid|cx|ie|cof|siteurl|zanpid|origin|utm_[a-z]+|mr:[A-z]+)=[%\._A-z0-9-]+&?", "");
    }
    set req.url = regsub(req.url, "(\?&|\?|&)$", "");
}

The first change is the part "[%._A-z0-9-]", because the dash functioned like a range symbol, that's why I've moved it to the end, and the dot should be escaped.

The second change is to not only remove a question mark at the remaining URL, but also an ampersand or question mark and ampersand.