Lesson 3 of 4 ยท Debugging Terraform

Required arguments and valid values

Provider errors often tell you that a resource is missing a required argument or has an invalid combination. Read the named arguments as a rule, then add the required configuration rather than guessing unrelated values.

Example

resource "aws_lb" "app" {
  name               = "app-lb"
  load_balancer_type = "application"
  subnets            = [aws_subnet.public.id]
}

Step by step

  1. Read the resource and argument named in the error.
  2. Check the provider documentation.
  3. Choose one valid combination.
  4. Plan again to find the next genuine issue.

Common mistakes to avoid

  • Adding every optional argument at once.
  • Using placeholder IDs in a configuration meant to be applied.