I deploy a number of services to Google Cloud Run. The services typically follow naming with “my-domain” and “www.my-domain” point to the frontend service, and “api.my-domain” point to the api service.
Cloud Run suggests to map “my-domain” to via A and AAAA records to 8 different IPs. That works absolutely fine so long as the records are “DNS only” and I use full SSL/TLS encryption mode.
The problem is with the subdomains. Cloud run suggests to map those via CNAME to “ghs.googlehosted.com.”. Setting that up doesn’t work, the domain doesn’t resolve. When I set up the subdomains using A and AAAA records by pointing them to the root domains IPs it all works fine, but that needs setting up 8 records for each subdomain!
Can someone help me understand how to correctly configure the DNS using CNAME to point to Cloud Run for my subdomains?