NGINX proxy for Google Analytics, allows you to bypass ad blockers

ga.example.com.conf

# /etc/nginx/sites-available/ga.example.com.conf
#
# Example of an host that uses the snippet

server {
    listen 80;
    server_name ga.example.com;

    # verify that the query relates to my account
    if ($arg_tid !~ "^$|^UA-XXXXXXXX-") { 
        return 403; 
    }

    include snippets/google-analytics-proxy.conf;
}

google-analytics-proxy.conf

# /etc/nginx/snippets/google-analytics-proxy.conf
#
# A reusable configuration to proxy Google Analytics

proxy_buffering on;
proxy_cache TMP;

location = /analytics.js {
    proxy_set_header Accept-Encoding "";
    sub_filter 'www.google-analytics.com'  $server_name;
    sub_filter_types *;
    sub_filter_once off;

    proxy_pass https://www.google-analytics.com/analytics.js;

    break;
}

location / {
    # Override IP address
    set $args $args&uip=$remote_addr;

    proxy_pass https://www.google-analytics.com; # CAUTION: no trailing slash
}

tmp-cache.conf

# /etc/nginx/conf.d/tmp-cache.conf
#
# Configure a small cache named TMP

proxy_cache_path  /tmp/nginx  keys_zone=TMP:10m max_size=100m;