The image shows an OCI region that contains a parent compartment and an Events instance, an Add DNS Record function and a Remove DNS Record function. The parent compartment within the region contains three availability domainsd (AD), which as spanned by a virtual cloud network (VCN). The VCN contains two private subnets, which themselves span all three ADs.

• Private subnet 1 contains a single VM in both the first and third ADs.
• Private subnet 2 contains two worker nodes, also VMs, in each of the three ADs.

Access to both subnets is controlled by individual cloud guard implementations and security lists. Access to the VCN is through either a service gateway or a NAT gateway.

• When the Events instance generates a instance launch, the Add DNS Record function is updated and passes that information through a private DNS zone, which associates the event with the VCN via a VCN DNS resolver.
• When the Events instance generates a instance terminate, the Add DNS Record function is updated and passes that information through a private DNS zone, which associates the event with the VCN via a VCN DNS resolver.