Previously this resource (and, by extension, the aws_ami_copy and
aws_ami_from_instance resources that share much of its implementation)
was handling correctly the case where an AMI had been recently
deregistered, and was thus still returned from the API, but not correctly
dealing with the situation where the AMI has been removed altogether.
Now we additionally handle the NotFound error returned by the API when
we request a non-existent AMI, and remove the AMI from the state in the
same way we do for deregistered AMIs.
This commit resolves the issue where lack of snapshot ID in the device mapping
section of the API response to DescribeImagesResponse would cause Terraform to
crash due to a nil pointer dereference. Usually, the snapshot ID is included,
but in some unique cases (e.g. ECS-enabled AMI from Amazon available on the
Market Place) a volume that is attached might not have it.
The API documentation does not clearly define whether the snapshot ID either
should be or must be included for any volume in the response.
Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
AWS provides three different ways to create AMIs that each have different
inputs, but once they are complete the same management operations apply.
Thus these three resources each have a different "Create" implementation
but then share the same "Read", "Update" and "Delete" implementations.