I have only gone as far as this
sudo mv /opt/bitnami/varnish/scripts/ctl.sh.disabled /opt/bitnami/varnish/scripts/ctl.sh
sudo /opt/bitnami/ctlscript.sh start varnish
My key requirement is to have the https traffic to use the varnish cache. So far I cannot make ssl traffic (port 443) to proxy_pass to http (80)
I will greatly appreciate the update of the documentation. I actually need it rather urgently.