fix: Add VPC ID validation for RAM service network discovery (#858)

Adds validation in findServiceNetworkViaVPCAssociation() to ensure
CLUSTER_VPC_ID environment variable is set before attempting to list
VPC-to-Service Network associations.

Provides clear error message when configuration is missing, making
debugging easier for RAM-shared service network deployments.

Co-authored-by: Dan Lutsch <dan.lutsch@trueaccord.com>
Co-authored-by: Ryan Lymburner <137918933+rlymbur@users.noreply.github.com>

Author: 3 people

pkg/aws/services/vpclattice.go

@@ -426,6 +426,11 @@ func (d *defaultLattice) buildServiceNetworkInfo(ctx context.Context, snMatch *v
 // by examining VPC associations. This is used to discover RAM-shared
 // service networks that don't appear in ListServiceNetworks.
 func (d *defaultLattice) findServiceNetworkViaVPCAssociation(ctx context.Context, nameOrId string) (*ServiceNetworkInfo, error) {
+	// Validate that VPC ID is configured
+	if config.VpcID == "" {
+		return nil, fmt.Errorf("cannot discover RAM-shared service networks: CLUSTER_VPC_ID environment variable is not set")
+	}
+
 	// List all VPC-to-Service Network associations for the controller's VPC
 	associations, err := d.ListServiceNetworkVpcAssociationsAsList(ctx,
 		&vpclattice.ListServiceNetworkVpcAssociationsInput{