To be able to dynamically write values to the nginx.tmpl file we maintain a master template nginx.tmpl.master.
This way we can add firewall rules etc.
In the staging environment it enhances security to be able to only allow selected IP addresses access for some hosts.
Add the hosts to protect to the FIREWALL_PROTECTED_HOSTS variable in the .env file as a comma separated list.
Then add the IP addresses that are allowed access to the IP whitelist section in the .env file.
To write the new values to the nginx.tmpl, run ./start.sh script in the root folder. It is sometimes necessary to
restart the docker containers with
docker restart nginx-gen
and
docker restart nginx-web