Updated Magento 2 Varnish 6 VCL, in cooperation with Varnish Software

varnish6.vcl

# A number of these changes come form the following PR's; , combines changes in https://github.com/magento/magento2/pull/29360, https://github.com/magento/magento2/pull/28944 and https://github.com/magento/magento2/pull/28894, https://github.com/magento/magento2/pull/35228, https://github.com/magento/magento2/pull/36524, https://github.com/magento/magento2/pull/34323
# VCL version 5.0 is not supported so it should be 4.0 even though actually used Varnish version is 6
vcl 4.1;

import std;
# The minimal Varnish version is 6.0
# For SSL offloading, pass the following header in your proxy server or load balancer: '/* {{ ssl_offloaded_header }} */: https'

backend default {
    .host = "/* {{ host }} */";
    .port = "/* {{ port }} */";
    .first_byte_timeout = 600s;
    .probe = {
        .url = "/health_check.php";
        .timeout = 2s;
        .interval = 5s;
        .window = 10;
        .threshold = 5;
   }
}

acl purge {
/* {{ ips }} */
}

sub vcl_recv {
    # Remove empty query string parameters
    # e.g.: www.example.com/index.html?    
    if (req.url ~ "\?$") {
        set req.url = regsub(req.url, "\?$", "");
    }

    # Remove port number from host header
    set req.http.Host = regsub(req.http.Host, ":[0-9]+", "");
    
    # Sorts query string parameters alphabetically for cache normalization purposes    
    set req.url = std.querysort(req.url);
    
    # Remove the proxy header to mitigate the httpoxy vulnerability
    # See https://httpoxy.org/    
    unset req.http.proxy;
    
    # Add X-Forwarded-Proto header when using https
    if (!req.http.X-Forwarded-Proto && (std.port(server.ip) == 443 || std.port(server.ip) == 8443)) {
        set req.http.X-Forwarded-Proto = "https";
    }
    
    # Reduce grace to the configured setting if the backend is healthy
    # In case of an unhealthy backend, the original grace is used
    if (std.healthy(req.backend_hint)) {
        set req.grace = /* {{ grace }} */s;
    }
    
    if (req.method == "PURGE") {
        if (client.ip !~ purge) {
            return (synth(405, "Method not allowed"));
        }
        # To use the X-Pool header for purging varnish during automated deployments, make sure the X-Pool header
        # has been added to the response in your backend server config. This is used, for example, by the
        # capistrano-magento2 gem for purging old content from varnish during it's deploy routine.
        if (!req.http.X-Magento-Tags-Pattern && !req.http.X-Pool) {
            return (purge);
        }
        if (req.http.X-Magento-Tags-Pattern) {
          ban("obj.http.X-Magento-Tags ~ " + req.http.X-Magento-Tags-Pattern);
        }
        if (req.http.X-Pool) {
          ban("obj.http.X-Pool ~ " + req.http.X-Pool);
        }
        return (synth(200, "Purged"));
    }

    if (req.method != "GET" &&
        req.method != "HEAD" &&
        req.method != "PUT" &&
        req.method != "POST" &&
        req.method != "PATCH" &&
        req.method != "TRACE" &&
        req.method != "OPTIONS" &&
        req.method != "DELETE") {
          return (pipe);
    }

    # We only deal with GET and HEAD by default
    if (req.method != "GET" && req.method != "HEAD") {
        return (pass);
    }

    # Bypass health check requests
    if (req.url ~ "^/(pub/)?(health_check.php)$") {
        return (pass);
    }

    # Collapse multiple cookie headers into one
    std.collect(req.http.Cookie);

    # Remove all marketing get parameters to minimize the cache objects
    if (req.url ~ "(\?|&)(gad_source|gclid|cx|_kx|ie|cof|siteurl|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=") {
        set req.url = regsuball(req.url, "(gad_source|gclid|cx|_kx|ie|cof|siteurl|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=[-_A-z0-9+()%.]+&?", "");
        set req.url = regsub(req.url, "[?|&]+$", "");
    }

    # Static files caching
    if (req.url ~ "^/(pub/)?(media|static)/") {
        # Static files should not be cached by default
        return (pass);

        # But if you use a few locales and don't use CDN you can enable caching static files by commenting previous line (#return (pass);) and uncommenting next 3 lines
        #unset req.http.Https;
        #unset req.http./* {{ ssl_offloaded_header }} */;
        #unset req.http.Cookie;
    }

    # Don't cache the authenticated GraphQL requests
    if (req.url ~ "/graphql" && req.http.Authorization ~ "^Bearer") {
        return (pass);
    }

    return (hash);
}

sub vcl_hash {
    if (req.url !~ "/graphql" && req.http.cookie ~ "X-Magento-Vary=") {
        hash_data(regsub(req.http.cookie, "^.*?X-Magento-Vary=([^;]+);*.*$", "\1"));
    }

    # To make sure http users don't see ssl warning
    hash_data(req.http./* {{ ssl_offloaded_header }} */);

    /* {{ design_exceptions_code }} */

    if (req.url ~ "/graphql") {
        if (req.http.X-Magento-Cache-Id) {
            hash_data(req.http.X-Magento-Cache-Id);
        } else {
            # if no X-Magento-Cache-Id (which already contains Store & Currency) is not set, use the HTTP headers
            hash_data(req.http.Store);
            hash_data(req.http.Content-Currency);
        }
    }
}

sub vcl_backend_response {
	# Serve stale content for three days after object expiration
	# Perform asynchronous revalidation while stale content is served
    set beresp.grace = 3d;

    # All text-based content can be parsed as ESI
    if (beresp.http.content-type ~ "text") {
        set beresp.do_esi = true;
    }

    # Allow GZIP compression on all JavaScript files and all text-based content
    if (bereq.url ~ "\.js$" || beresp.http.content-type ~ "text") {
        set beresp.do_gzip = true;
    }
    
    # Add debug headers
    if (beresp.http.X-Magento-Debug) {
        set beresp.http.X-Magento-Cache-Control = beresp.http.Cache-Control;
    }

    # Only cache HTTP 200 and HTTP 404 responses
    if (beresp.status != 200 && beresp.status != 404) {
        set beresp.ttl = 120s;
        set beresp.uncacheable = true;
        return (deliver);
    }
    
    # Don't cache if the request cache ID doesn't match the response cache ID for graphql requests
    if (bereq.url ~ "/graphql" && bereq.http.X-Magento-Cache-Id && bereq.http.X-Magento-Cache-Id != beresp.http.X-Magento-Cache-Id) {
       set beresp.ttl = 120s;
       set beresp.uncacheable = true;
       return (deliver);
    }

    # Remove the Set-Cookie header for cacheable content
    # Only for HTTP GET & HTTP HEAD requests
    if (beresp.ttl > 0s && (bereq.method == "GET" || bereq.method == "HEAD")) {
        unset beresp.http.Set-Cookie;
    }
}

sub vcl_deliver {
    if (obj.uncacheable) {
        set resp.http.X-Magento-Cache-Debug = "UNCACHEABLE";
    } else if (obj.hits) {
        set resp.http.X-Magento-Cache-Debug = "HIT";
        set resp.http.Grace = req.http.grace;
    } else {
        set resp.http.X-Magento-Cache-Debug = "MISS";
    }

    # Not letting browser to cache non-static files.
    if (resp.http.Cache-Control !~ "private" && req.url !~ "^/(pub/)?(media|static)/") {
        set resp.http.Pragma = "no-cache";
        set resp.http.Expires = "-1";
        set resp.http.Cache-Control = "no-store, no-cache, must-revalidate, max-age=0";
    }

    if (!resp.http.X-Magento-Debug) {
        unset resp.http.Age;
    }
    unset resp.http.X-Magento-Debug;
    unset resp.http.X-Magento-Tags;
    unset resp.http.X-Powered-By;
    unset resp.http.Server;
    unset resp.http.X-Varnish;
    unset resp.http.Via;
    unset resp.http.Link;
}

@peterjaap Here's the notes I added for my team, with pwa studio references for usage

---

Seems magento 2.4.4 and above, and latest PWA studio have improved cacheability for GQL requests
https://devdocs.magento.com/guides/v2.4/graphql/caching.html#customers

Magento generates a x-cache-id variation - https://github.com/magento/magento2/blob/192b28038dac2e993c65b49fb8b5af10cb520945/app/code/Magento/PageCache/etc/varnish6.vcl#L116-L148

PWA studio constantly grabs it from the response, and updates it to attach to the next requests so that when you log in etc you change customer groups / get cacheability
magento/pwa-studio@626ea1f#diff-b638977b4ea6fd3f29b668736551ed752c5b3915805df1af2f1a7579a006aacbR27

https://github.com/magento/pwa-studio/blob/626ea1f1c384654703501783b219bc7c4efa672d/packages/peregrine/lib/Apollo/links/gqlCacheLink.js#L41

@peterjaap The Varnish6.vcl file below you diff has the following code:

sub process_graphql_headers {
    if (req.http.X-Magento-Cache-Id) {
        hash_data(req.http.X-Magento-Cache-Id);

        # When the frontend stops sending the auth token, make sure users stop getting results cached for logged-in users
        if (req.http.Authorization ~ "^Bearer") {
            hash_data("Authorized");
        }
    }

    hash_data(req.http.Store);

    hash_data(req.http.Content-Currency);
}

This code implies that authorized /graphql calls can be cached in Magento. Is that the desired behavior? I was under the impression that authorized /graphql calls should bypass the cache.

Please clarify.

This specific example implies that caching happens only when X-Magento-Cache-Id is set then, it additionally may add Authorization to it. Although, by default, GraphQL API allows doing queries without Authorization for stuff like catalog, so definitely looks strange.

Also, Authorization makes the cache user-specific, which removes any benefit of caching it in the Varnish server side, as if you have a spike of 1000 users, each of which will generate 1000 variations of the same cache.
I would probably remove Authorization header from the request in vcl_recv if X-Magento-Cache-Id is specified to prevent caching of customer-sensitive data in the first place. As a side effect, it should increase the cache hit ratio, as I imagine Authorization is added automatically if the request is sent when the user gets logged in. But that is implementation specific of the frontend that uses GraphQL, which should always separate customer-specific queries form cacheable ones.

@JeroenBoersma But that is if you use Nginx as a TLS proxy. I actually advise using Hitch as a TLS proxy:

• It's developed by Varnish Software
• It's open source
• It's a pure TLS proxy that has no HTTP awareness
• It supports both PROXY protocol version 1 & 2

See https://www.varnish-software.com/developers/tutorials/terminate-tls-varnish-hitch/ for more information about Hitch and Varnish.

@ThijsFeryn If it would be just SSL termination than that's a true point, in this case it's a combined effort for file serving and (generated) content you get a performance gain by serving the files directly from the server and using Varnish for the generated content. There is no need to cache these static files on the same server in Varnish.

rewrite /pub/health_check.php /health_check.php;

A customer notified us with a list of more marketing pixels....

I think we can include these in the list of parameters to...
https://maxchadwick.xyz/tracking-query-params-registry/ props to @mpchadwick

Source which links to the above list: https://www.rumvision.com/blog/make-sure-to-check-your-caching-rules/

A customer notified us with a list of more marketing pixels....

I think we can include these in the list of parameters to... https://maxchadwick.xyz/tracking-query-params-registry/ props to @mpchadwick

Source which links to the above list: https://www.rumvision.com/blog/make-sure-to-check-your-caching-rules/

@JeroenBoersma: here's the updated VCL:

    if (req.url ~ "(\?|&)(_branch_match_id|_bta_[a-z]+|campid|customid|_ga|gclid|gclsrc|gdf[a-z]+|cx|dm_i|ef_id|epik|ie|igshid|cof|hsa_[a-z]+|_ke|mk[a-z]{3}|msclkid|(mtm|matomo)_[a-z]+|pcrid|p(iwi)?k_[a-z]+|redirect(_log)?_mongo_id|siteurl|s_kwcid|sb_referer_host|si|trk_[a-z]+|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=") {
        set req.url = regsuball(req.url, "(_branch_match_id|_bta_[a-z]+|campid|customid|_ga|gclid|gclsrc|cx|dm_i|ef_id|epik|ie|igshid|cof|hsa_[a-z]+|_ke|mk[a-z]{3}|msclkid|(mtm|matomo)_[a-z]+|pcrid|p(iwi)?k_[a-z]+|redirect(_log)?_mongo_id|siteurl|s_kwcid|sb_referer_host|si|trk_[a-z]+|zanpid|origin|fbclid|mc_[a-z]+|utm_[a-z]+|_bta_[a-z]+)=[-_A-z0-9+()%.]+&?", "");
        set req.url = regsub(req.url, "[?|&]+$", "");
    }

@peterjaap and @ThijsFeryn magento/magento2#37524

These marketing pixels should be ignored when hitting graphql otherwise you'll endup regsub way more than you expect. Sometimes, likely unexpectedly, there's a relative URL (with query params) hidden inside the URL.

You have an error on line 44, the close bracket before the || needs removing.

@chrisastley thanks!

Can we add the "gad_source" parameter?
Source: https://support.google.com/google-ads/answer/13327296?hl=en & https://www.rumvision.com/use-cases/making-sure-paid-traffic-has-the-best-page-speed-possible/

@Melleschepers added!

sub process_graphql_headers {
if (req.http.X-Magento-Cache-Id) {
hash_data(req.http.X-Magento-Cache-Id);

    # When the frontend stops sending the auth token, make sure users stop getting results cached for logged-in users
    if (req.http.Authorization ~ "^Bearer") {
        hash_data("Authorized");
    }
}

hash_data(req.http.Store);

hash_data(req.http.Content-Currency);

}
Can we remove Authorization token from frontend as ‘X-Magento-Cache-Id’ already there which provide Authorization so no need of bearer token?