From https://www.nginx.com/resources/wiki/start/topics/recipes/drupal/

drupal.conf

server {
    server_name example.com;
    root /var/www/drupal8; ## <-- Your only path reference.

    location = /favicon.ico {
        log_not_found off;
        access_log off;
    }

    location = /robots.txt {
        allow all;
        log_not_found off;
        access_log off;
    }

    # Very rarely should these ever be accessed outside of your lan
    location ~* \.(txt|log)$ {
        allow 192.168.0.0/16;
        deny all;
    }

    location ~ \..*/.*\.php$ {
        return 403;
    }

    location ~ ^/sites/.*/private/ {
        return 403;
    }

    # Allow "Well-Known URIs" as per RFC 5785
    location ~* ^/.well-known/ {
        allow all;
    }

    # Block access to "hidden" files and directories whose names begin with a
    # period. This includes directories used by version control systems such
    # as Subversion or Git to store control files.
    location ~ (^|/)\. {
        return 403;
    }

    location / {
        # try_files $uri @rewrite; # For Drupal <= 6
        try_files $uri /index.php?$query_string; # For Drupal >= 7
    }

    location @rewrite {
        rewrite ^/(.*)$ /index.php?q=$1;
    }

    # Don't allow direct access to PHP files in the vendor directory.
    location ~ /vendor/.*\.php$ {
        deny all;
        return 404;
    }

    # In Drupal 8, we must also match new paths where the '.php' appears in the middle,
    # such as update.php/selection. The rule we use is strict, and only allows this pattern
    # with the update.php front controller.  This allows legacy path aliases in the form of
    # blog/index.php/legacy-path to continue to route to Drupal nodes. If you do not have
    # any paths like that, then you might prefer to use a laxer rule, such as:
    #   location ~ \.php(/|$) {
    # The laxer rule will continue to work if Drupal uses this new URL pattern with front
    # controllers other than update.php in a future release.
    location ~ '\.php$|^/update.php' {
        fastcgi_split_path_info ^(.+?\.php)(|/.*)$;
        #NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
        fastcgi_intercept_errors on;
        fastcgi_pass unix:/var/run/php5-fpm.sock;
    }

    # Fighting with Styles? This little gem is amazing.
    # location ~ ^/sites/.*/files/imagecache/ { # For Drupal <= 6
    location ~ ^/sites/.*/files/styles/ { # For Drupal >= 7
        try_files $uri @rewrite;
    }

    location ~* \.(js|css|png|jpg|jpeg|gif|ico)$ {
        expires max;
        log_not_found off;
    }
}