func readBlockDevicesFromInstance(instance *ec2.Instance, ec2conn *ec2.EC2) (map[string]interface{}, error) {
blockDevices := make(map[string]interface{})
blockDevices["ebs"] = make([]map[string]interface{}, 0)
blockDevices["root"] = nil
instanceBlockDevices := make(map[string]ec2.InstanceBlockDeviceMapping)
for _, bd := range instance.BlockDeviceMappings {
if bd.EBS != nil {
instanceBlockDevices[*(bd.EBS.VolumeID)] = bd
}
}
if len(instanceBlockDevices) == 0 {
return nil, nil
}
volIDs := make([]string, 0, len(instanceBlockDevices))
for volID := range instanceBlockDevices {
volIDs = append(volIDs, volID)
}
// Need to call DescribeVolumes to get volume_size and volume_type for each
// EBS block device
volResp, err := ec2conn.DescribeVolumes(&ec2.DescribeVolumesRequest{
VolumeIDs: volIDs,
})
if err != nil {
return nil, err
}
for _, vol := range volResp.Volumes {
instanceBd := instanceBlockDevices[*vol.VolumeID]
bd := make(map[string]interface{})
if instanceBd.EBS != nil && instanceBd.EBS.DeleteOnTermination != nil {
bd["delete_on_termination"] = *instanceBd.EBS.DeleteOnTermination
}
if vol.Size != nil {
bd["volume_size"] = *vol.Size
}
if vol.VolumeType != nil {
bd["volume_type"] = *vol.VolumeType
}
if vol.IOPS != nil {
bd["iops"] = *vol.IOPS
}
if blockDeviceIsRoot(instanceBd, instance) {
blockDevices["root"] = bd
} else {
if instanceBd.DeviceName != nil {
bd["device_name"] = *instanceBd.DeviceName
}
if vol.Encrypted != nil {
bd["encrypted"] = *vol.Encrypted
}
if vol.SnapshotID != nil {
bd["snapshot_id"] = *vol.SnapshotID
}
blockDevices["ebs"] = append(blockDevices["ebs"].([]map[string]interface{}), bd)
}
}
return blockDevices, nil
}
