Your company’s cloud security policy dictates that VM instances should not have an external IP...

Cloud NAT Service: Use Cloud NAT (Network Address Translation) to allow VM instances without external IP addresses to access the internet securely.

Configuration: Configure Cloud NAT for the subnets containing your VM instances. This setup allows the VMs to initiate outbound connections to the internet for updates and other necessary communications.

Security Compliance: By using Cloud NAT, you adhere to the security policy of not assigning external IP addresses to VMs while still enabling necessary internet connectivity. Cloud NAT provides a secure method for outbound internet traffic without exposing VMs directly to the public internet. References:

Google Cloud - Cloud NAT Overview

Google Cloud - Configuring Cloud NAT