Cache issues

[meyskens]

Terraform Version

terraform v0.12.3

Affected Resource(s)

• All resources

Terraform Configuration Files

I have made an example repo for Terraform 0.11 which works (but may have issues as stated in #50): https://github.com/meyskens/tf-ignition-011
I ported the same codebase to Terraform 0.12 where this seems to always happens https://github.com/meyskens/tf-ignition-012-fail
The example is quite complex, this was because i wanted to investigate another issue. Happy to try to reproduce it on a simpler project if needed.

Expected Behavior

IDs be pulled out of the cache when being passed in igniton_config

Actual Behavior

Error: invalid file "c521f5d49123e48489100eaebf01a2b438653ada9d1a00839958076b85e2992d", unknown file id

  on baremetal/ignition.tf line 209, in data "ignition_config" "prometheus_worker":
 209: data "ignition_config" "prometheus_worker" {
[...]

Steps to Reproduce

1. terraform apply

Notes

I made an implementation that removes the cache in a PR. Not 100% sure this is the best approach to solve this issue. But it solved the bug for me. Happy to discuss this as this is a very breaking change.
#56