Resolved Login via FQDN hostname no longer works for me

[FifthRateIntellectual]

I'm running Obsidian 18.0.40 on Ubuntu 20.04 on a DigitalOcean droplet. When I first set up Pleask, I did not specify any hostname. I was able to log in properly using the IP address, and also using the temporary hostname supplied by Plesk when you first install the software. I've been able to setup up a couple of domains, email, WordPress, and even a docker container running Ghost, with no problems. Everything is working well.

I decided to finally update the temporary hostname to a FQDN based on one of the hosted domains on plesk. For the hostname, I chose admin.DOMAIN.com. Plesk reported that the change had been processed. I then went to Tools/Settings and ensured that the Plesk site was being encrypted by Let's Encrypt. I could see that the hostname was properly listed. After waiting for a bit for the Let's Encrypt process to complete, I logged out. I then went to the login screen using the IP address, and the usual "To avoid SSL warnings during Plesk login, use https://admin.DOMAIN.com:8443" message appeared. I clicked on the link, and was able to log in using the hostname, and the resultant page was properly encrypted.

After about a day, however, using the FQDN for login no longer works for some reason, throwing the error ERR_NAME_NOT_RESOLVED.

I checked out a few things using the terminal. The hostname is reported correctly as the FQDN, and /etc/hosts shows that both the localhost and droplet IP are associated with the new hostname.

This isn't a huge deal for me, but I would like to know if I've missed some kind of obvious step. I can't understand why it would work one day, but not on the next. Any help or insights would be greatly appreciated.

Grace and peace.

 

[Kaspar]

An "ERR_NAME_NOT_RESOLVED" error usually means that the DNS record is missing or not configured correctly. Did you check if the DNS record can be resolved?

 

[FifthRateIntellectual]

Interesting. There is no DNS record for the domain.

I suppose that makes sense, however, because I'm changing the hostname and doing nothing with the domain. Should plesk add the A record if I choose a hostname which corresponds with a domain I'm hosting on plesk?

If not, is the proper correction to add the necessary "A" record to DNS myself, or should I add a subdomain that matches the hostname?

 

[FifthRateIntellectual]

Interesting. There is no DNS record for the domain.

I suppose that makes sense, however, because I'm changing the hostname and doing nothing with the domain. Should plesk add the A record if I choose a hostname which corresponds with a domain I'm hosting on plesk?

If not, is the proper correction to add the necessary "A" record to DNS myself, or should I add a subdomain that matches the hostname?

To be clear, there is not DNS entry for the subdomain which I have used as the hostname. There *is* a DNS record for the primary domain name.

 

[Kaspar]

Just add an DNS ("A") record for you hostname.

 

[FifthRateIntellectual]

Thank you. All is well!