How should you pass the value of an input variable called environment from a parent module to a child module?

To pass the value of an input variable called "environment" from a parent module to a child module, declaring it as an input variable in the child module allows the parent module to provide that value explicitly. This approach establishes a clear contract for data flow between modules, ensuring that the parent module can set the variable when calling the child module.

When declaring the "environment" variable in the child module, the child module needs to have this variable defined within a variables.tf file (or similar) to accept the input. When the parent module calls the child module, it can set this variable explicitly, promoting modularity and reusability of the child module across different environments.

The variability of the "environment" input allows the parent module to change this value without modifying the child module, adhering to best practices in infrastructure as code by keeping modules independent and encapsulated. This approach supports Terraform's design principles centered on modular and reusable code.

Other options do not facilitate a structured way to pass variable values between modules effectively. For instance, declaring it as a local variable in the child module would not allow the parent module to set the value, and a global variable would violate the principles of encapsulation and modularity by making variables accessible in an uncontrolled manner