Terranix

terranix generates Terraform JSON from Nix modules. You write config.nix; the terranix tool (or a flake build) produces config.tf.json, which OpenTofu (tofu) applies exactly like HCL — same providers, same state, same plan/apply workflow.

Prefer OpenTofu over Terraform when the user hasn't pinned a choice: it's in nixpkgs as pkgs.opentofu, command tofu, reads the same .tf.json files, and resolves providers from its own registry mirror.

Two rules that prevent most mistakes:

• config.tf.json is a build artifact. Never hand-edit it; regenerate it. Gitignore it along with state (see below).
• Nix and Terraform share the ${} syntax (see Interpolation escaping) — this clash is the single biggest source of broken terranix configs.