Cannot request letsencrypt cert for a website with the same hostname as the server

Ubuntu 16.04

Summary: When a website is created with the same hostname as the server, the let's encrypt challenge process fails.

What happens: Parsing account key... Parsing CSR... Registering account... Already registered! Verifying mydomain.com... Traceback (most recent call last): File "/usr/share/webmin/webmin/acme_tiny.py", line 203, in main(sys.argv[1:]) File "/usr/share/webmin/webmin/acme_tiny.py", line 199, in main signed_crt = get_crt(args.account_key, args.csr, args.acme_dir, log=LOGGER, CA=args.ca) File "/usr/share/webmin/webmin/acme_tiny.py", line 128, in get_crt wellknown_path, wellknown_url)) ValueError: Wrote file to /home/user/public_html/.well-known/acme-challenge/xxxchallengestringxxx, but couldn't download http://mydomain.com/.well-known/acme-challenge/xxchallengestringxxx

What was expected: The challenge to succeed

Causes: The hostname of the server resolves to 127.0.0.1, due to the /etc/hosts. The website in apache is listening on 192.168.x.x address for both port 80 and 443, the port 80 website redirects to the port 443 website.

It looks like the letsencrypt client tries to download the file locally first to verify it's there? It will never be able to download the challenge file in this scenario because it's requesting on 127.0.0.1, but the website is only listening on 192.168.x.x. I do see the access attempts in /var/log/apache2/other_vhosts_access.log which seems to verify this.

Solutions: If I comment out the whole "check that the file is in place" block of acme_tiny.py, my cert is successfully requested.