Using AWS ALB to have subdomains pointing to different target groups
Right now I have a domain (example.com) that I have hosted on Google Domains, but uses Amazon's Route 53 DNS servers, and I've created a hosted zone & registered an SSL certificate for free with ACM. So I got it to take requests for example.com and forwards them to a target group (EC2 instance).
I'd like to expand this into:
staging.example.comprod.example.com
where each has its own target group it points to.
Is this possible with an ALB? How would I encode this into the load balancer's routing rules?
(Also: would I have to re-verify the SSL cert for the subdomains?)
You route each subdomain to different target group using Listener Rules
When you add a Listener Rule, set a condition for Host header and select the subdomain you want to use e.g. staging.example.com and select Forward to as your target group.
Regarding SSL, you won't need to create a new certificate as long as you have the certificate for *.example.com attached to the listener (see View/Edit certificates)