Add Google Analytics tracking code to HTML via nginx

analytics.conf

#
# Add Google Analytics tracking code to HTML response
#
# Usage:
#   set $tracking_id 'UA-12345678-9';
#   include incl/analytics.conf;
#
# It needs nginx compiled with option --with-http_sub_module.
# Uses optimized GA code from: http://mathiasbynens.be/notes/async-analytics-snippet
#
sub_filter '</head>' '<script type="text/javascript">var _gaq=[["_setAccount","$tracking_id"],["_trackPageview"]];(function(d,t){var g=d.createElement(t),s=d.getElementsByTagName(t)[0];g.async=1;g.src="//www.google-analytics.com/ga.js";s.parentNode.insertBefore(g,s)})(document,"script")</script></head>';

pagespeed module has this as a built-in feature. https://www.modpagespeed.com/doc/filter-insert-ga

pagespeed on;

# This line is optional. Use it if you only want manually enabled filters to be active.
# Details https://www.modpagespeed.com/doc/config_filters
pagespeed RewriteLevel passthrough;

pagespeed EnableFilters insert_ga;
pagespeed AnalyticsID <Analytics ID>;

Hi @kurtabersold @jacobdr & @jirutka

How exactly does this work? You compile the open source version of Nginx with this module, and then you add this line to each location block and it will automatically inject the Google Analytics tracking code into the proxied page? Apache, plex, or whatever?

EDIT: I've done so, and nginx starts up cleanly without any errors. But I don't see any data appearing in Google Analytics unfortunately. Is
this a valid example of an http block including the analytics tracking code?

http {
    server  {
        listen  443 ssl;
        server_name www.website.com;
        ssl  on;
        location  / {
            proxy_pass http://12.34.56.78:2000/;

            sub_filter   </head>
                    "<script>
                        <!-- Global site tag (gtag.js) - Google Analytics -->
                        <script async src='https://www.googletagmanager.com/gtag/js?id=UA-##########-1'></script>
                        <script>
                          window.dataLayer = window.dataLayer || [];
                          function gtag(){dataLayer.push(arguments);}
                          gtag('js', new Date());
    
                      gtag('config', 'UA-##########-1');
                    </script>
                </script>";
            sub_filter_once on;
    }
}

EDIT2: I found further information here but am still unable to piece this together.

EDIT3: I did a little digging and learned about the analytics.js file. I've attempted to implement this and also finding it's still not working. Is it necessary to forward ports or anything for this?

http {
    server  {
        listen  443 ssl;
        server_name www.website.com;
        ssl  on;
        location  / {
            proxy_pass http://12.34.56.78:2000/;

            sub_filter </head> '<script>(function(i,s,o,g,r,a,m){i["GoogleAnalyticsObject"]=r;i[r]=i[r]||function(){(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)})(window,document,"script","https://www.google-analytics.com/analytics.js","ga");ga("create","UA-##########","auto");ga("send","pageview");</script></head>';        
            
            sub_filter_once on;
    }
}

EDIT4: I tried calling an entirely separate js file containing the code as well but it still isn't working unfortunately.

http {
    server  {
        listen  443 ssl;
        server_name www.website.com;
        ssl  on;
        location  / {
            proxy_pass http://12.34.56.78:2000/;

            sub_filter  </head>
            '<script language="javascript" src="/etc/nginx/analytics.js"></script></head>';
            sub_filter_once on;
    }
}

The analytics.js file in question:

<!-- Google Analytics -->
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

ga('create', 'UA-##########', 'auto');
ga('send', 'pageview');
</script>
<!-- End Google Analytics -->

Hi, did you get any luck to make it work?