show the challenge that is being used on renewals

[jvanasco]

on first execution, this shows the required CNAME configuration

it would be nice to show the existing/expected configuration on renewal

if a DNS record gets wiped, it's kind of a pain to dig this information out. the easiest way to renew is to delete the acme-dns config data, which can have repercussions.

[joohoi]

Good idea! I'll probably add a cli flag to dig this information out.

[jas-per]

just had the problem with wiping a DNS record by accident - credentials and CNAME for all domains are in /etc/letsencrypt/acmedns.json no need to delete your acme-dns config data