How does certificate manager work for multiple domians

Question

I'm working with certification manager, Can someone pls explain me certification manager for multiple certificates.

For example

domain_name = foo.dev
alternate_domian_names = *.foo.dev , bar.com

so should create CNAME record for all 3 domain name (foo.dev,*foo.dev and bar.com) and validate for all the 3?

Answer 1

For the DNS foo.dev,*.foo.dev these seem to same parent DNS so single validation will work and you will need to add bar.com so All you will need to create 2 CNAME for the above DNS validation one for foo.dev and one for bar.com.

You can also compare CNAME record for foo.com or *.foo.com it should be same that is generated by AWS ACM.

You can attach a maximum 10 Domain names for each ACM certificate by default.

Understanding Automatic Domain Validation

To validate a domain, ACM sends automated, periodic HTTPS requests to it. For domains that start with www., ACM also sends HTTPS requests to the parent domain. For example, if your domain is www.example.com, ACM sends periodic requests to www.example.com and to example.com. For domains that don't start with www., ACM also sends HTTPS requests to www.domain. ACM treats wildcard domain names (for example, *.example.com) the same as the parent domain. For examples, see the following table.

How ACM domain validation works