Exam Terraform Associate topic 1 question 291 discussion

Output values have several uses: A child module can use outputs to expose a subset of its resource attributes to a parent module. A root module can use outputs to print certain values in the CLI output after running terraform apply.

Accessing Child Module Outputs In a parent module, outputs of child modules are available in expressions as module.<MODULE NAME>.<OUTPUT NAME>. For example, if a child module named web_server declared an output named instance_ip_addr, you could access that value as module.web_server.instance_ip_addr.

child modules send outputs to root module and then the root module prints the outputs.

True. Output values are stored in state file. Only after a terraform apply, it knows that there are values in state file. Running terraform output output_name results in warning Warning: No outputs found. The state file either has no outputs defined, or all the defined outputs are empty. Please define an output in your configuration with the `output` keyword and run `terraform refresh` for it to become available. If you are using interpolation, please verify the interpolated value is not empty. You can use the `terraform console` command to assist.