Find all the attached volumes for an EC2 instance

Question

I'm using the below code to get all the available volumes under EC2. But I can't find any Ec2 api to get already attached volumes with an instance. Please let me know how to get all attached volumes using instanceId.

EC2Api ec2Api = computeServiceContext.unwrapApi(EC2Api.class);
List<String> volumeLists = new ArrayList<String>();
if (null != volumeId) {
    volumeLists.add(volumeId);
}
String[] volumeIds = volumeLists.toArray(new String[0]);
LOG.info("the volume IDs got from user is ::"+ Arrays.toString(volumeIds));

Set<Volume> ec2Volumes = ec2Api.getElasticBlockStoreApi().get()
                    .describeVolumesInRegion(region, volumeIds);

Set<Volume> availableVolumes = Sets.newHashSet();
for (Volume volume : ec2Volumes) {
    if (volume.getSnapshotId() == null
            && volume.getStatus() == Volume.Status.AVAILABLE) {
        LOG.debug("available volume with no snapshots ::" + volume.getId());
        availableVolumes.add(volume);
   }
}

Answer 1

The AWS Java SDK now provides a method to get all the block device mappings for an instance. You can use that to get a list of all the attached volumes:

// First get the EC2 instance from the id
DescribeInstancesRequest describeInstancesRequest = new DescribeInstancesRequest().withInstanceIds(instanceId);
DescribeInstancesResult describeInstancesResult = ec2.describeInstances(describeInstancesRequest);
Instance instance = describeInstancesResult.getReservations().get(0).getInstances().get(0);

// Then get the mappings
List<InstanceBlockDeviceMapping> mappingList = instance.getBlockDeviceMappings();
for(InstanceBlockDeviceMapping mapping: mappingList) {
    System.out.println(mapping.getEbs().getVolumeId());
}