How to mock a remote call so the Internet is not required during testing

I think my question is rather simple. I want to define some Terraform tests using mock_provider. Of course, I don’t want those provider to actually make remote calls (thus requiring the Internet). I simply want to override various behaviors in those providers to return mock data.

Concrete example
I am using the following provider:

    http = {
      source  = "hashicorp/http"
      version = "~> 3.4"

I am making simple HTTP calls (expecting 200 response codes):

lifecycle {
    postcondition {
      condition     = contains([200], data.http.validate_backstage_system.status_code) 
      error_message = "System not found in Backstage"

data "http" "validate_backstage_system" {
  url = "${var.my_system}"

I am mocking the provider using:

mock_provider "http"    {}

I always get the following response:

│ Error: Resource postcondition failed
│   on line 115, in resource "datadog_service_level_objective" "dd_slo":
│  115:       condition     = contains([200], data.http.validate_backstage_system.status_code)  # located here below
│     ├────────────────
│     │ data.http.validate_backstage_system.status_code is 0
│ System not found in Backstage

The bottom-line question is:

  • how do I define the mock_provider so that I can avoid making the actual HTTP calls?
  • it’s got to be some version of override_module, override_data, or override_resource
  • but ALL examples on the web are only for aws and there’s very, very little info anywhere for the mock_provider ability

I will answer my own question. After the better part of about 2 hours, I’ve finally found this solution:

mock_provider "http" {
  override_data {
    target = data.http.validate_backstage_system
    values = { status_code = "200"}

I really just wish the mock_provider docs provided more examples than just for aws …and for more relatively common use cases.