static void Main(string publicIp = "") { if (string.IsNullOrEmpty(publicIp)) { throw new Exception("Must provide a public IP to assign using --public-ip"); } var client = new AmazonEC2Client(); var instanceId = EC2InstanceMetadata.InstanceId; client.AssociateAddressAsync(new AssociateAddressRequest { InstanceId = instanceId, PublicIp = publicIp }).Wait(); Console.WriteLine($"Finished assigning {publicIp} to {instanceId}"); }