What is a requirement for version constraints in Terraform 0.13 and later configurations?

In Terraform 0.13 and later, version constraints are indeed defined in the required_providers block. This is a significant change introduced to help manage and specify which versions of providers should be used in your Terraform configurations. By using the required_providers block, you can set version constraints that ensure compatibility and stability in your infrastructure as code.

This allows for better control over the behavior of your Terraform configurations, making sure that the appropriate provider versions are used when running your infrastructure deployments. This feature also facilitates easier management of provider upgrades and ensures that any new features or changes in provider behavior won't unexpectedly affect your existing infrastructure.

Version constraints serve as a way to safeguard your configurations from breaking changes by allowing you to specify the range of acceptable versions for a provider, thereby enhancing the reliability of your Terraform deployments. Specifying version constraints in this manner is a best practice, as it helps avoid any unforeseen issues that might arise from automatic upgrades to newer provider versions.