How can I get a list of my EC2 instances that have assigned Elastic IPs?

Question

How can I get a list of my EC2 instances that have assigned static public Elastic IPs using C#?

Answer 1

Basically you will get instances and public IP-s, then you will compare if instance contains any public IP address.

Here is the code which will do that for you:

                AmazonEC2 ec2 = AWSClientFactory.CreateAmazonEC2Client();

                //Create instance request
                DescribeInstancesRequest request = new DescribeInstancesRequest();
                DescribeInstancesResponse response = ec2.DescribeInstances(request);

                //Create ip address request enumeration
                DescribeAddressesRequest daRequest = new DescribeAddressesRequest();
                DescribeAddressesResponse daResponse = ec2.DescribeAddresses(daRequest);
                var publicIps = from ips in daResponse.DescribeAddressesResult.Address select ips.PublicIp;

                //List of the instances which has public IP
                List<RunningInstance> publicIpInstances = new List<RunningInstance>();

                //Iterate over instances and check if they have public IP
                foreach (Reservation ri in response.DescribeInstancesResult.Reservation)                    
                    publicIpInstances.AddRange(ri.RunningInstance.Where(inst => publicIps.Contains(inst.IpAddress)));