Inconsistent opinion on common name field

[stevenpitts]

website/content/docs/usage/certificate.md

Lines 66 to 67 in eab7224

	# The use of the common name field has been deprecated since 2000 and is
	# discouraged from being used.

As explored and summarized in caddyserver/caddy#3755 (comment), the deprecation of the CN field has some ambiguity. I don't have an opinion one way or the other, but cert-manager discourages its use and documents usage of it in a "Bootstrapping CA Issuers" example:

website/content/docs/configuration/selfsigned.md

Line 100 in eab7224

commonName: my-selfsigned-ca

If commonName were removed from that example, applying it would result in an error:

at least one of commonName, dnsNames, uriSANs, ipAddresses, emailSANs or otherNames must be set

The language in the comment should be made less absolute, or the usage of commonName in examples should be replaced with a field that is not deprecated.

[SgtCoDFish]

Fair comment to make!

I think we should say that the use of commonName is discouraged for end-entity certificates, where the SAN extension is simply better. For CA certs commonName is fine. I'll create a PR to try and capture that 🔨

[inteon]

fixed in #1548