If VARNISH_DRUPAL_PRESERVED_COOKIES is set, required Session and No_Cache cookies are also gets stripped contrary to documentation. Also, it's not clear how to handle multiple cookies with VARNISH_DRUPAL_PRESERVED_COOKIES on composer.yml
dockercompose:
VARNISH_DRUPAL_PRESERVED_COOKIES: "example"
actual varnish container "preset.vcl":
`/ # cat /etc/varnish/preset.vcl
sub vcl_recv {
# Pass through any administrative or AJAX-related paths.
if (req.url ~ "^(/update\.php|/([a-z]{2}/)?admin|/([a-z]{2}/)?admin/.*|/([a-z]{2}/)?system/files/.*|/([a-z]{2}/)?flag/.*|.*/ajax/.*|.*/ahah/.*)$") {
return (pass);
}
if (req.url ~ "(^/([a-z]{2}/)?batch)") {
return (pipe);
}
# Remove all cookies that Drupal doesn't need to know about. We explicitly
# list the ones that Drupal does need, the SESS and NO_CACHE. If, after
# running this code we find that either of these two cookies remains, we
# will pass as the page cannot be cached.
if (req.http.Cookie) {
# 1. Append a semi-colon to the front of the cookie string.
# 2. Remove all spaces that appear after semi-colons.
# 3. Match the cookies we want to keep, adding the space we removed
# previously back. (\1) is first matching group in the regsuball.
# 4. Remove all other cookies, identifying them by the fact that they have
# no space after the preceding semi-colon.
# 5. Remove all spaces and semi-colons from the beginning and end of the
# cookie string.
set req.http.Cookie = ";" + req.http.Cookie;
set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
set req.http.Cookie = regsuball(req.http.Cookie, ";(example)=", "; \1=");
set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
if (req.http.Cookie == "") {
# If there are no remaining cookies, remove the cookie header. If there
# aren't any cookie headers, Varnish's default behavior will be to cache
# the page.
unset req.http.Cookie;
}
else {
# If there is any cookies left (a session or NO_CACHE cookie), do not
# cache the page. Pass it on to Apache directly.
return (pass);
}
}
the default value of VARNISH_DRUPAL_PRESERVED_COOKIES is a regex that instructs what matched cookies to preserve, if current cookies match any of this, the page will not be cached
If VARNISH_DRUPAL_PRESERVED_COOKIES is set, required Session and No_Cache cookies are also gets stripped contrary to documentation. Also, it's not clear how to handle multiple cookies with VARNISH_DRUPAL_PRESERVED_COOKIES on composer.yml
dockercompose: VARNISH_DRUPAL_PRESERVED_COOKIES: "example" actual varnish container "preset.vcl": `/ # cat /etc/varnish/preset.vcl sub vcl_recv {
}`