What hash function does the Azure Container Instances (ACI) DNS reuse policy use?

Question

I need to programmatically set ACI fqdn, but this is made difficult since the default DNS name reuse policy adds a random portion to the fqdn which is a hash of the DNS name and the tenant ID. If I knew the hash function I could generate the hash and thus know what the actual fqdn will be.

Answer 1

Hi @Reuben Cummings
Thank you for reaching out to the Microsoft Q&A platform.

I understand that you want to programmatically set the fully qualified domain name (FQDN) for your Azure Container Instance (ACI), but you are having difficulty doing so because the default DNS name reuse policy adds a random portion to the FQDN which is a hash of the DNS name and the tenant ID. Unfortunately, the hash function used to generate the random portion of the FQDN is not publicly documented, so it is not possible to generate the hash yourself.

However, you can set the DNS name reuse policy to "noReuse" when creating the ACI, which will prevent the random portion from being added to the FQDN.

Hope this helps!