feat: Add support to return default resource group details (#728)

Author: whoffler

README.md

@@ -6,13 +6,14 @@
 [![Renovate enabled](https://img.shields.io/badge/renovate-enabled-brightgreen.svg)](https://renovatebot.com/)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
 
-This module returns the ID for the name of a resource group. It can also create a group from a name and return the ID.
+This module returns the ID for the name of a resource group. It can also create a group from a name and return the ID. The module will return the ID of the default resource group if no name is passed.
 
 <!-- Below content is automatically populated via pre-commit hook -->
 <!-- BEGIN OVERVIEW HOOK -->
 ## Overview
 * [terraform-ibm-resource-group](#terraform-ibm-resource-group)
 * [Examples](./examples)
+    * [Default resource group example](./examples/default-resource-group)
     * [Existing resource group example](./examples/existing-resource-group)
     * [New resource group example](./examples/new-resource-group)
 * [Contributing](#contributing)
@@ -38,6 +39,13 @@ module "resource_group" {
   existing_resource_group_name = "existing-resource-group"
 }
 ```
+Return ID of the default Resource group:
+```hcl
+module "resource_group" {
+  source                       = "terraform-ibm-modules/resource-group/ibm"
+  version                      = "X.X.X" # Replace "X.X.X" with a release version to lock into a specific release
+}
+```
 
 ### Required IAM access policies
 You need the following permissions to run this module.
@@ -63,13 +71,14 @@ No modules.
 | Name | Type |
 |------|------|
 | [ibm_resource_group.resource_group](https://registry.terraform.io/providers/IBM-Cloud/ibm/latest/docs/resources/resource_group) | resource |
+| [ibm_resource_group.default](https://registry.terraform.io/providers/IBM-Cloud/ibm/latest/docs/data-sources/resource_group) | data source |
 | [ibm_resource_group.existing_resource_group](https://registry.terraform.io/providers/IBM-Cloud/ibm/latest/docs/data-sources/resource_group) | data source |
 
 ### Inputs
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
-| <a name="input_existing_resource_group_name"></a> [existing\_resource\_group\_name](#input\_existing\_resource\_group\_name) | Name of the existing resource group.  Required if not creating new resource group | `string` | `null` | no |
+| <a name="input_existing_resource_group_name"></a> [existing\_resource\_group\_name](#input\_existing\_resource\_group\_name) | Name of the existing resource group. When null, set to the account's default resource group. | `string` | `null` | no |
 | <a name="input_resource_group_name"></a> [resource\_group\_name](#input\_resource\_group\_name) | Name of the resource group to create. Required if not using existing resource group | `string` | `null` | no |
 
 ### Outputs

examples/default-resource-group/README.md

@@ -0,0 +1,3 @@
+# Default resource group example
+
+An example showing how when no resource group or existing resource group is passed, the module can look up and return the default Resource group ID as an output.

examples/default-resource-group/main.tf

@@ -0,0 +1,3 @@
+module "resource_group" {
+  source = "../../"
+}

examples/default-resource-group/outputs.tf

@@ -0,0 +1,9 @@
+output "resource_group_name" {
+  value       = module.resource_group.resource_group_name
+  description = "Resource group name"
+}
+
+output "resource_group_id" {
+  value       = module.resource_group.resource_group_id
+  description = "Resource group ID"
+}

examples/default-resource-group/provider.tf

@@ -0,0 +1,3 @@
+provider "ibm" {
+  ibmcloud_api_key = var.ibmcloud_api_key
+}

examples/default-resource-group/variables.tf

@@ -0,0 +1,5 @@
+variable "ibmcloud_api_key" {
+  type        = string
+  description = "The IBM Cloud API Token"
+  sensitive   = true
+}

examples/default-resource-group/version.tf

@@ -0,0 +1,12 @@
+terraform {
+  required_version = ">= 1.9.0"
+
+  # Ensure that there is always 1 example locked into the lowest provider version of the range defined in the main
+  # module's version.tf (this example), and 1 example that will always use the latest provider version (new-resource-group example).
+  required_providers {
+    ibm = {
+      source  = "IBM-Cloud/ibm"
+      version = "1.79.0"
+    }
+  }
+}

main.tf

@@ -1,16 +1,28 @@
 ##############################################################################
 # terraform-ibm-resource-group-module
 #
-# Looks up resource group and creates a new one if none already exists
+# Creates a resource group if a new one is requested.
+# Otherwise it will look up a provided existing resource group or the account's default resource group
 ##############################################################################
 
+# Use a local variable to determine if the default resource group should be used
+locals {
+  # Use the local variable to decide which resource group name to use
+  existing_resource_group_name = var.existing_resource_group_name != null ? var.existing_resource_group_name : var.resource_group_name == null ? data.ibm_resource_group.default[0].name : null
+}
+
+data "ibm_resource_group" "default" {
+  count      = var.existing_resource_group_name == null && var.resource_group_name == null ? 1 : 0
+  is_default = "true"
+}
+
 data "ibm_resource_group" "existing_resource_group" {
-  count = var.existing_resource_group_name != null ? 1 : 0
-  name  = var.existing_resource_group_name
+  count = var.resource_group_name != null ? 0 : 1
+  name  = local.existing_resource_group_name
 }
 
 resource "ibm_resource_group" "resource_group" {
-  count    = var.existing_resource_group_name != null ? 0 : 1
+  count    = var.resource_group_name != null ? 1 : 0
   name     = var.resource_group_name
   quota_id = null
 }

outputs.tf

@@ -4,11 +4,11 @@
 
 output "resource_group_name" {
   description = "Resource group name"
-  value       = var.existing_resource_group_name != null ? data.ibm_resource_group.existing_resource_group[0].name : ibm_resource_group.resource_group[0].name
+  value       = var.resource_group_name == null ? data.ibm_resource_group.existing_resource_group[0].name : ibm_resource_group.resource_group[0].name
 }
 
 output "resource_group_id" {
   description = "Resource group ID"
-  value       = var.existing_resource_group_name != null ? data.ibm_resource_group.existing_resource_group[0].id : ibm_resource_group.resource_group[0].id
+  value       = var.resource_group_name == null ? data.ibm_resource_group.existing_resource_group[0].id : ibm_resource_group.resource_group[0].id
 }
 ##############################################################################

tests/pr_test.go

@@ -11,13 +11,13 @@ import (
 	"github.com/gruntwork-io/terratest/modules/logger"
 	"github.com/gruntwork-io/terratest/modules/random"
 	"github.com/gruntwork-io/terratest/modules/terraform"
-	"github.com/stretchr/testify/require"
-
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/terraform-ibm-modules/ibmcloud-terratest-wrapper/testhelper"
 )
 
 const newGroupExampleTerraformDir = "examples/new-resource-group"
+const defaultGroupExampleTerraformDir = "examples/default-resource-group"
 const existingGroupExampleTerraformDir = "examples/existing-resource-group"
 
 func TestRunNewGroupExample(t *testing.T) {
@@ -96,6 +96,20 @@ func TestRunExistingGroupExample(t *testing.T) {
 	}
 }
 
+func TestRunDefaultGroupExample(t *testing.T) {
+	t.Parallel()
+
+	options := testhelper.TestOptionsDefault(&testhelper.TestOptions{
+		Testing:      t,
+		TerraformDir: defaultGroupExampleTerraformDir,
+	})
+
+	output, err := options.RunTestConsistency()
+	assert.Nil(t, err, "This should not have errored")
+	assert.NotEmpty(t, output.RawPlan.OutputChanges["resource_group_id"].After.(string))
+	assert.Equal(t, output.RawPlan.OutputChanges["resource_group_name"].After.(string), "Default")
+}
+
 func TestRunUpgradeExample(t *testing.T) {
 	t.Skip()
 	t.Parallel()