Add terragrunt example as a first class example on terratest.gruntwor…

…k.io (#994)

* Add terragrunt example as a first class example on terratest.gruntwork.io

* Fix web tags in go test

.circleci/config.yml

@@ -5,7 +5,7 @@ env: &env
     MODULE_GCP_CI_VERSION: v0.1.1
     TERRAFORM_VERSION: 1.0.3
     PACKER_VERSION: 1.7.4
-    TERRAGRUNT_VERSION: v0.31.4
+    TERRAGRUNT_VERSION: v0.32.3
     GO_VERSION: 1.16.3
     GO111MODULE: auto
     K8S_VERSION: v1.15.0  # Same as EKS

docs/_data/examples.yml

@@ -51,6 +51,21 @@
     - name: Kubernetes Hello, World
       url: https://github.com/gruntwork-io/terratest/tree/master/examples/kubernetes-hello-world-example
 
+- id: terragrunt-hello-world
+  name: Terragrunt Example
+  image: /assets/img/logos/terragrunt-logo.png
+  files:
+    - url: /examples/terragrunt-example/terragrunt.hcl
+      id: terragrunt_code
+    - url: /examples/terragrunt-example/main.tf
+      id: terraform_code
+    - url: /test/terragrunt_example_test.go
+      id: test_code
+      default: true
+  learn_more:
+    - name: Terragrunt
+      url: https://github.com/gruntwork-io/terratest/tree/master/examples/terragrunt-example
+
 - id: aws-hello-world
   name: AWS Hello, World Example
   image: /assets/img/logos/aws-logo.png

examples/terragrunt-example/README.md

@@ -0,0 +1,31 @@
+# Terragrunt Example
+
+This folder contains the simplest possible Terragrunt module—one that just passes inputs to terraform-to demonstrate how
+you can use Terratest to write automated tests for your Terragrunt code.
+
+Check out [test/terragrunt_example_test.go](/test/terragrunt_example_test.go) to see how you can
+write automated tests for this simple module.
+
+Note that this module doesn't do anything useful; it's just here to demonstrate the simplest usage pattern for
+Terratest.
+
+
+
+
+## Running this module manually
+
+1. Install [Terraform](https://www.terraform.io/) and make sure it's on your `PATH`.
+1. Install [Terragrunt](https://terragrunt.gruntwork.io/) and make sure it's on your `PATH`.
+1. Run `terragrunt apply`.
+1. When you're done, run `terragrunt destroy`.
+
+
+
+
+## Running automated tests against this module
+
+1. Install [Terraform](https://www.terraform.io/) and make sure it's on your `PATH`.
+1. Install [Terragrunt](https://terragrunt.gruntwork.io/) and make sure it's on your `PATH`.
+1. Install [Golang](https://golang.org/) and make sure this code is checked out into your `GOPATH`.
+1. `cd test`
+1. `go test -v -run TestTerragruntExample`

test/terragrunt_example_test.go

@@ -0,0 +1,28 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/gruntwork-io/terratest/modules/terraform"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTerragruntExample(t *testing.T) {
+	// website::tag::3:: Construct the terraform options with default retryable errors to handle the most common retryable errors in terraform testing.
+	terraformOptions := terraform.WithDefaultRetryableErrors(t, &terraform.Options{
+		// website::tag::1:: Set the path to the Terragrunt module that will be tested.
+		TerraformDir: "../examples/terragrunt-example",
+		// website::tag::2:: Set the terraform binary path to terragrunt so that terratest uses terragrunt instead of terraform. You must ensure that you have terragrunt downloaded and available in your PATH.
+		TerraformBinary: "terragrunt",
+	})
+
+	// website::tag::6:: Clean up resources with "terragrunt destroy" at the end of the test.
+	defer terraform.Destroy(t, terraformOptions)
+
+	// website::tag::4:: Run "terragrunt apply". Under the hood, terragrunt will run "terraform init" and "terraform apply". Fail the test if there are any errors.
+	terraform.Apply(t, terraformOptions)
+
+	// website::tag::5:: Run `terraform output` to get the values of output variables and check they have the expected values.
+	output := terraform.Output(t, terraformOptions, "output")
+	assert.Equal(t, "one input another input", output)
+}