def _resolve_module_variable()

in samcli/hook_packages/terraform/hooks/prepare/resource_linking.py [0:0]

• 38 lines of code
• 18 McCabe index (conditional complexity)

def _resolve_module_variable(module: TFModule, variable_name: str) -> List[Union[ConstantValue, ResolvedReference]]:
    # return a list of the values that resolve the passed variable
    # name in the input module.
    results: List[Union[ConstantValue, ResolvedReference]] = []

    LOG.debug("Resolving module variable for module (%s) and variable (%s)", module.module_name, variable_name)

    var_value = module.variables.get(variable_name)

    if not var_value:
        raise InvalidResourceLinkingException(
            message=f"The variable {variable_name} could not be found in module {module.module_name}."
        )

    # check the possible constant value for this variable
    if isinstance(var_value, ConstantValue) and var_value is not None:
        LOG.debug("Found a constant value (%s) in module (%s)", var_value.value, module.module_name)
        results.append(ConstantValue(var_value.value))

    # check the possible references value for this variable
    if isinstance(var_value, References) and var_value is not None:
        LOG.debug("Found references (%s) in module (%s)", var_value.value, module.module_name)
        cleaned_references = _clean_references_list(var_value.value)
        for reference in cleaned_references:
            LOG.debug("Resolving reference: %s", reference)
            # refer to a variable passed to this module from its parent module
            if reference.startswith("var."):
                config_var_name = get_configuration_address(reference[len("var.") :])
                if module.parent_module:
                    results += _resolve_module_variable(module.parent_module, config_var_name)
            # refer to another module output. This module will be defined in the same level as this module
            elif reference.startswith("module."):
                module_name = reference[reference.find(".") + 1 : reference.rfind(".")]
                config_module_name = get_configuration_address(module_name)
                output_name = reference[reference.rfind(".") + 1 :]
                if (
                    module.parent_module
                    and module.parent_module.child_modules
                    and module.parent_module.child_modules.get(config_module_name)
                ):
                    # using .get() gives us Optional[TFModule], if conditional already validates child module exists
                    # access list directly instead
                    child_module = module.parent_module.child_modules[config_module_name]
                    results += _resolve_module_output(child_module, output_name)
                else:
                    raise InvalidResourceLinkingException(f"Couldn't find child module {config_module_name}.")
            # this means either a resource, data source, or local.variables.
            elif module.parent_module:
                results.append(ResolvedReference(reference, module.parent_module.full_address))
            else:
                raise InvalidResourceLinkingException("Resource linking entered an invalid state.")

    return results