Raspberry Pi Farm upgrade

Today i have upgraded my Raspberry Pi farm:
– Upgrade OS (bullseye) to latest version
– Created wildcard *.plaatsoft.nl HTTP certificate
– Added HaProxy software load balancer (disable Apache reverse proxy)
– Now load balancer is taking care of the HTTPS offloading
– Now load balancer route HTTP traffic to correct apache node
– Upgrade WordPress to v6.0.2 and wordpress plugins

Letsencrypt wildcard certificate

To enable a Letsencrypt wildcard certificate do the following steps

Create NEW wildcard certificate

1. Stop Apache or HaProxy
2. Run following certbot command to create a wildcard certificate
sudo certbot certonly -d '*.plaatsoft.nl' --manual

3. Certbot will ask you to add an extra DNS entry (TXT) with a unique token
Add this record in your DNS

4. Check with dig tool if DNS record is available (This can take some time)
sudo dig _acme-challenge.plaatsoft.nl TXT

5. Press "enter". Then wildcard certifate is created
6. Add new certificate to Apache or HaProxy.
7. Remove DNS TXT record (Updating it does not work, is my experience)
8. Done