Provided by: varnish_7.7.0-1_amd64 
NAME
vmod_cookie - Varnish Cookie Module
SYNOPSIS
import cookie [as name] [from "path"]
VOID clean()
VOID delete(STRING cookiename)
VOID filter(STRING filterstring)
VOID filter_re(REGEX expression)
VOID keep(STRING filterstring)
VOID keep_re(REGEX expression)
STRING format_date(TIME now, DURATION timedelta)
STRING get(STRING cookiename)
STRING get_re(REGEX expression)
STRING get_string()
BOOL isset(STRING cookiename)
VOID parse(STRING cookieheader)
VOID set(STRING cookiename, STRING value)
DESCRIPTION
Handle HTTP cookies more easily in Varnish VCL.
Parses a cookie header into an internal data store, where per-cookie get/set/delete functions are
available. A keep() function removes all but a set comma-separated list of cookies. A filter() function
removes a comma- separated list of cookies.
Regular expressions can be used for either selecting cookies, deleting matching cookies and deleting
non-matching cookie names.
A convenience function for formatting the Set-Cookie Expires date field is also included.
The state loaded with cookie.parse() has a lifetime of the current request or backend request context. To
pass variables to the backend request, store the contents as fake bereq headers.
Filtering example:
import cookie;
sub vcl_recv {
if (req.http.cookie) {
cookie.parse(req.http.cookie);
# Either delete the ones you want to get rid of:
cookie.delete("cookie2");
# or delete all but a few:
cookie.keep("SESSIONID,PHPSESSID");
# Store it back into req so it will be passed to the backend.
set req.http.cookie = cookie.get_string();
# If empty, unset so the builtin VCL can consider it for caching.
if (req.http.cookie == "") {
unset req.http.cookie;
}
}
}
VOID clean()
Clean up previously parsed cookies. It is not necessary to run clean() in normal operations.
Example:
sub vcl_recv {
cookie.clean();
}
VOID delete(STRING cookiename)
Delete cookiename from internal vmod storage if it exists.
Example:
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2");
cookie.delete("cookie2");
# get_string() will now yield "cookie1=value1"
}
VOID filter(STRING filterstring)
Delete all cookies from internal vmod storage that are in the comma-separated argument cookienames.
Example:
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2; cookie3=value3");
cookie.filter("cookie1,cookie2");
# get_string() will now yield "cookie3=value3"
}
VOID filter_re(REGEX expression)
Delete all cookies from internal vmod storage that matches the regular expression expression.
Example:
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2; cookie3=value3");
cookie.filter_re("^cookie[12]$");
# get_string() will now yield "cookie3=value3"
}
VOID keep(STRING filterstring)
Delete all cookies from internal vmod storage that is not in the comma-separated argument cookienames.
Example:
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2; cookie3=value3");
cookie.keep("cookie1,cookie2");
# get_string() will now yield "cookie1=value1; cookie2=value2"
}
VOID keep_re(REGEX expression)
Delete all cookies from internal vmod storage that does not match expression expression.
Example:
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2; cookie3=value3");
cookie.keep_re("^cookie[12]$");
# get_string() will now yield "cookie1=value1; cookie2=value2"
}
STRING format_date(TIME now, DURATION timedelta)
Get a RFC1123 formatted date string suitable for inclusion in a Set-Cookie response header.
Care should be taken if the response has multiple Set-Cookie headers. In that case the header vmod
should be used.
Example:
sub vcl_deliver {
# Set a userid cookie on the client that lives for 5 minutes.
set resp.http.Set-Cookie = "userid=" + req.http.userid +
"; Expires=" + cookie.format_date(now, 5m) + "; httpOnly";
}
STRING get(STRING cookiename)
Get the value of cookiename, as stored in internal vmod storage.
Example:
import std;
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2");
std.log("cookie1 value is: " + cookie.get("cookie1"));
}
If cookiename does not exist, the NULL string is returned. Note that a NULL string is converted to an
empty string when assigned to a header. This means that the following is correct:
if (req.http.Cookie) {
cookie.parse(req.http.Cookie);
set req.http.X-tmp = cookie.get("a_cookie");
} else {
set req.http.X-tmp = "";
}
if (req.http.X-tmp != "") {
// do something with the X-tmp header...
} else {
// fallback case
}
However, using cookie.isset() is often a better way to check if a particular cookie is present, like
this:
unset req.http.X-tmp; # unnecessary if no fallback is needed
if (req.http.Cookie) {
cookie.parse(req.http.Cookie);
if (cookie.isset("a_cookie")) {
set req.http.X-tmp = cookie.get("a_cookie");
# do something with the X-tmp header...
}
}
# if necessary, do something when a_cookie is not there
if (!req.http.X-tmp) {
# fallback case
}
STRING get_re(REGEX expression)
Get the value of the first cookie in internal vmod storage that matches the regular expression
expression. If nothing matches, the NULL string is returned.
Example:
import std;
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2");
std.log("cookie1 value is: " + cookie.get_re("^cookie1$"));
}
STRING get_string()
Get a Cookie string value with all cookies in internal vmod storage. Does not modify internal storage.
Example:
sub vcl_recv {
cookie.parse(req.http.cookie);
cookie.keep("SESSIONID,PHPSESSID");
set req.http.cookie = cookie.get_string();
}
BOOL isset(STRING cookiename)
Check if cookiename is set in the internal vmod storage.
Example:
import std;
sub vcl_recv {
cookie.parse("cookie1=value1; cookie2=value2");
if (cookie.isset("cookie2")) {
std.log("cookie2 is set.");
}
}
VOID parse(STRING cookieheader)
Parse the cookie string in cookieheader. If state already exists, clean() will be run first.
Example:
sub vcl_recv {
cookie.parse(req.http.Cookie);
}
VOID set(STRING cookiename, STRING value)
Set the internal vmod storage for cookiename to value.
Example:
sub vcl_recv {
cookie.set("cookie1", "value1");
std.log("cookie1 value is: " + cookie.get("cookie1"));
}
DEPRECATED
ALIAS format_rfc1123()
Deprecated alias for format_date().
COPYRIGHT
This document is licensed under the same conditions as Varnish itself.
See LICENSE for details.
SPDX-License-Identifier: BSD-2-Clause
VMOD_COOKIE(3)