How to Setup a Dummy Site for Let's Encrypt with TurnKey Linux

Open the proxmox manager (DNS should look like https://VirtMan-XX.yourdomainspace.com:8006). Login with a DomainAdmins account.

Install a fresh TurnKey Linux LAMP Stack using one of the available template in proxmox.
See How to Setup a TurnKey Linux Container

Now that you have a LAMP Stack running, you will need to connect to it using the 'root' account.

ssh root@403.yourdomainspace.com

Once connected, you will be ask to create the mysql 'root' password. We are now able to download the dummy index page locally using:

wget https://wiki.laswitchtech.com/downloads/index.php

Next, we will empty the current public directory using :

rm -vfr /var/www/*

Now we can insert our dummy page in the public directory using :

cp -vR index.php /var/www/

Finally we need to set the appropriate permission on the site by using:

chown -vR www-data:www-data /var/www/
chmod 444 /var/www/*

You now have a dummy site setup to create Let's Encrypt certificates for your internal sites.

You can use Let's Encrypt to provide the SSL Certificate for your NextCloud installation. TurnKey Linux already provides a simple interface to make those changes to you Stack. You can enter :

confconsole

From there, you can go into the <Advanced Menu> and select “Let's encrypt”.

Once there, we first need to generate a certificate by selecting “Get certificate”. You will get a tips explaining that to create the certificate, a valid DNS record must exist on the web. If this is not the case, make sure you configure one. If this site is only displayed in the internal network, just configure a dummy web server and create a DNS record that points to it online. This will allow CertBot to find something in order to confirm that the certificate you are requesting points to a site that exist. Now you can enter all the valid DNS Record that points to the NextCloud site.

Now that you have your certificate, you should enable the automatic renewal of the certificate.

Let's Encrypt is now configured.