Comprehensive and Detailed Explanation From Exact Extract:
The problem is that the on-premises developers cannot resolve the Artifact Registry hostname, and they have no route to the internet. This is a classic DNS resolution problem in a hybrid network using private API access.
Artifact Registry is a Google-managed service, and its hostname (e.g., us-west1-docker.pkg.dev) resolves to a Google API domain. To access Google services privately from an on-premises network without an internet route, the traffic must be directed to Private Google Access IP ranges.
Issue: The on-premises DNS cannot resolve the Google service domain to the required private IP range.
Solution: The on-premises DNS needs a record (or a forwarding rule) to resolve the Google service domain to the dedicated IP ranges used for Private Google Access, specifically restricted.googleapis.com or private.googleapis.com (which provide the IP addresses for private access).
Extracts (Conceptual Basis):
"To direct traffic privately, you must ensure that your on-premises network's DNS is configured to resolve Google API and service domain names to the IP address range for Private Google Access." (Source 1.1)
"The IP addresses for private.googleapis.com are used for Private Google Access. To enable on-premises hosts to access Google APIs and services using this method, you must configure on-premises DNS to resolve requests for Google API domain names to the IP address range for private.googleapis.com." (Source 1.2)
Option B is incorrect because Private Google Access (PGA) is enabled on the VPC subnet, allowing VMs within the VPC to access Google APIs. However, the problem is with the on-premises developers; the on-premises DNS must be configured to resolve the hostname correctly.
