Error when adding an alias DNS record to Lightsail Zone

Yes, Amazon Lightsail DNS zones do support alias records, but there are some specific requirements and limitations.

When creating an alias record in Lightsail, you need to set the isAlias parameter to true to specify that the domain entry is an alias used by AWS resources like Lightsail load balancers, container services, CDN distributions, or other AWS resources.

The error you're encountering suggests that the format of the target you're providing isn't recognized as a valid DNS name by Lightsail. Unlike Route 53, which has broader support for various AWS resource aliases including S3 website endpoints, Lightsail's alias support appears to be more limited.

Lightsail DNS zones primarily support creating alias records that point to Lightsail's own resources (load balancers, container services, CDN distributions). There may be limitations when trying to create an alias to an S3 website endpoint directly in Lightsail DNS.

If you're trying to add an alias record to an S3 website endpoint, you might need to continue using Route 53 for this specific functionality, as Lightsail DNS may not fully support all the same alias targets that Route 53 does.

For Lightsail container services specifically, note that adding an alias record to point to them requires using the AWS CLI rather than the console interface.
Sources
DomainEntry - Amazon Lightsail
Route domain traffic to a Lightsail container service using Route 53 - Amazon Lightsail
I cannot add a DNS record to any new/existing Lightsail DNS Zone | AWS re:Post

Hello,

Thank you for your question.

Like the AI Generated response, I want to re-iterate the following:

Lightsail's DNS management system has limited support when it comes to ALIAS records unlike Route 53. This is an important limitation to be aware of.

Documentation: https://docs.aws.amazon.com/lightsail/2016-11-28/api-reference/API_DomainEntry.html

Here's the detailed explanation:

Route 53 specifically has the ALIAS record type which is an AWS-proprietary feature that allows pointing to AWS resources like S3 websites, CloudFront distributions, and other AWS services.

Lightsail's DNS management is more basic and is designed for simpler use cases. It only supports standard DNS record types (A, AAAA, CNAME, MX, etc.). When it comes to ALIAS Records, Lightsail allows you to point it to limited resources like Lightsail load balancer, Lightsail container service, Lightsail content delivery network (CDN) distribution,

For your specific case, you have a few options:

• Keep using Route 53 for DNS management (recommended if you need ALIAS functionality)
• If you must use Lightsail DNS, you would need to point directly to the S3 website endpoint using a CNAME record instead. However, this won't work for apex domains (example.com) as CNAME records are not allowed at the apex.

Recommendation: If you're using S3 website hosting with ALIAS records, it's better to stick with Route 53 for DNS management.