Introduction
With the release of Terraform version 0.15.0, workspaces in Terraform Enterprise can now begin using this version to perform plans and applies. If workspaces are subject to Sentinel Policy checks, then those checks will begin to fail when using Terraform version 0.15.0 or later with a Terraform Enterprise version of v202103-3 or earlier.
Use Case
When using Terraform version 0.15.0 or later for workspace runs with Terraform Enterprise version of v202103-3 or earlier Sentinel policy checks will begin to fail. This is because support for Terraform version 0.15.0 or later was not added to Sentinel until version 0.18.0, which was not included in Terraform Enterprise until version v202104-1.
Procedure
The specific error that will be encountered when using Terraform version 0.15.0 in a Terraform Enterprise version of v202203-3 or earlier would be the following.
An error occurred: unsupported provider schema data format version: expected "0.1", got "0.2"The reason this issue is seen is there are changes introduced to the schema generated for the Sentinel Mocks when using Terraform 0.15.0. Sentinel versions prior to 0.18.0 are unable to support the schema generated in the Sentinel mocks for Terraform version 0.15.0.
The solution to this issue is to upgrade Terraform Enterprise to version v202104-1 or later. More information on how to upgrade a Terraform Enterprise instance can be found in the official documentation:
https://www.terraform.io/docs/enterprise/admin/upgrades.html