每个通配符子域指向不同的IP地址

Question

I have been using AWS Route-53 as dns service for my application and say in my code, for every http request I have a requirement of creating some dynamic sub-domains and point it to the new ec2 instance that gets created on fly.

Any one should now be able to use the newly created sub-domain to make requests to the newly created ec2 instance.

I knew I could use wildcard dns record, but does it not just point to one single IP?

How could I make every sub-domain that was created to always point to the new ec2 instance?

Answer 1

traefik is exactly what I needed. I configured traefik with etcd as it's provider and just by making entries to etcd server, I could achieve what I wanted.

Now I just have a wild card domain mapped to an ec2 instance on which I run traefik which watches etcd server for any new entries with /traefik/ as it's prefix. It then dynamically generates new configuration and takes care of routing any request to the destination server based on the HOST header.

Answer 2

Create an A record of *.example.com and assign the value to the IP address.

If any sub domain does not have an explicit record it will default to this record.

Possible solutions for auto adding DNS record.

• When creating an EC2 instance add a tag of the domain name(s) that should be assigned to resolve to this instance. Have CloudWatch event detect "StartInstance", then trigger a Lambda to add DNS record via API.
• Write a proxy that can determine the IP address to use for each subdomain. Or instead have it manually added through some kind of automation (SSM/Ansible).