If you want to stay with multi-tenancy (managing many sites with Crafter), then you simply front Engine with a WebServer to automatically indicate the crafterSite
in the URL. As an added bonus, you'll have the WebServer serve the static assets which is much faster. Here is an example vhost configuration for Apache HTTPd:
<VirtualHost *:80>
ServerName example.com
DocumentRoot /path_to_crafter/crafter/data/repos/sites/mysite
RewriteEngine On
RewriteRule (.*) $1?crafterSite=mysite [QSA,PT]
ProxyPreserveHost On
ProxyPass / ajp://localhost:8009/
ProxyPassReverse / ajp://localhost:8009/
ErrorLog ${APACHE_LOG_DIR}/mysite-error.log
CustomLog ${APACHE_LOG_DIR}/mysite-access.log combined
</VirtualHost>
Alternatively, if you just want to run a single site, you may disable multi-tenancy and have Engine deliver a single site. This link has more detail on that: https://docs.craftercms.org/en/3.0/system-administrators/engine/configure-engine-multi-tenancy.html