Terraform 1.15 ships dynamic module sources, variable deprecation

Summary

Removes friction from multi-environment infrastructure code by letting teams parameterize registry and version targets without duplicating entire module blocks. Deprecation tooling surfaces breaking changes directly in config validation instead of release notes.

Why it matters

Removes friction from multi-environment infrastructure code by letting teams parameterize registry and version targets without duplicating entire module blocks. Deprecation tooling surfaces breaking changes directly in config validation instead of release notes.

Sources

1. 1.dynamic module sources, a formal deprecation mechanism for variables and outputs, a new inline type conversion function, type constraints for output blocks, and native Windows ARM64 support
2. 2.previously, these had to be string literals, which forced teams to duplicate module blocks when they needed to point different environments at different registries or version pins
3. 3.when the deprecation grace period ends, authors can release a new module version without the deprecated variable and replace all references to the old one
4. 4.the feature extends to nested modules as long as their input variables are also declared with const = true
5. 5.OpenTofu shipped equivalent functionality in version 1.8.0, released in August 2024