In python module troposphere I am getting an error “AttributeError: 'module' object has no attribute 'EBSBlockDeviceMapping'”

Question

I'm following the example of some other code that has been written. The code in question looks like this:

   if virtualname == "ebs":
        if deviceSize == None:
            deviceSize = 8

            if delOnTerminate == None or delOnTerminate == "true":
                DOT = "true"
            else:
                DOT = "false"

        lc.BlockDeviceMappings.append(ec2.EBSBlockDeviceMapping(
                                            DeviceName=blockname,
                                            Ebs=ec2.EBSBlockDevice(VolumeSize=deviceSize,
                                                                   DeleteOnTermination=DOT)))
    else:
        lc.BlockDeviceMappings.append(ec2.BlockDeviceMapping(DeviceName=blockname,
                                                             VirtualName=virtualname))

Answer 1

The AttributeError happens only when you have a class (in this case a module) and refer to an attribute that doesn't exist. It is like a NameError but for attributes of objects.

You have imported a module like import ... as ec2 . The module marked ... does not have a function called EBSBlockDeviceMapping , so when you call it in your code, it gives an AttributeError .

Answer 2

Here is what works:

        lc.BlockDeviceMappings.append(ec2.BlockDeviceMapping(
                DeviceName = blockname,
                Ebs=ec2.EBSBlockDevice(
                    VolumeSize = deviceSize,
                    DeleteOnTermination = DOT
                    )
                )
        )

As pointed out by Reticality, EBSBlockDeviceMapping does not exist. Instead, I just needed to use BlockDeviceMapping and the ec2.EBSBlockDevice takes care of the EBS setup.

Oh yeah, and the argument for DOT needs to be a boolean and not a string so use 'DOT = False' and 'DOT = True' rather than 'DOT = "false"' and 'DOT = "true"'