Improve docs for Terraform CLI example

examples/terraform/complex_cli_only/README.md

@@ -0,0 +1,44 @@
+> [!IMPORTANT]
+> If your module can be used directly as a root module, consider following the [simple_cli_only](../simple_cli_only) example instead.
+
+This example meets the
+[Marketplace requirements](https://cloud.google.com/marketplace/docs/partners/vm/configure-terraform-deployment#requirements_for_custom_terraform_modules)
+for a Terraform **CLI Only** module
+
+If the `examples/marketplace_test` folder exists, marketplace will validate your
+module by executing:
+
+```
+terraform -chdir=examples/marketplace_test init
+terraform -chdir=examples/marketplace_test plan -var project_id=<test-project>
+```
+
+The module in `examples/marketplace_test` must reference your module in the root
+directory as shown below:
+
+```
+# The test module references the module in the root directory
+module "test" {
+  source = "../.."
+}
+```
+
+This test module can be used to create resources that the module in your root
+directory assumes already exists. For instance, this example creates a second
+network interface that is passed as an argument to the module in the root
+directory.
+
+For a Marketplace Partner to reuse this module, they must:
+
+1.  Declare "image" as a variable in Producer Portal.
+1.  Replace the default value of "image" with the image declared in Producer
+    Portal
+1.  Zip the module and upload to GCS
+
+```
+zip terraform.zip * -r
+gsutil cp terraform.zip gs://<YOUR-BUCKET>/<FOLDER>/terraform.zip
+```
+
+Additionally, Partners should include a README.md containing instructions on how
+to deploy their product.

examples/terraform/simple_cli_only/examples/marketplace_test/main.tf → examples/terraform/complex_cli_only/examples/marketplace_test/main.tf

@@ -13,17 +13,25 @@
 # limitations under the License.
 
 provider "google" {
-  project = var.project
+  project = var.project_id
 }
 
 # The test module references the module in the root directory
 module "test" {
   source = "../.."
+
+  other_nic = google_compute_network.new_nic.name
+}
+
+# Create a network interface in the test module. The Marketplace validation project
+# may not have a resource that your module in the root directory expects to exist.
+resource "google_compute_network" "new_nic" {
+  name = "new-test-nic"
 }
 
 # The module must declare a project variable that Marketplace can
 # set for validation
-variable "project" {
+variable "project_id" {
   type = string
 }
 

examples/terraform/complex_cli_only/main.tf

@@ -0,0 +1,35 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+resource "google_compute_instance" "default" {
+  name         = "example"
+  machine_type = "e2-medium"
+  zone         = "us-central1-a"
+
+  boot_disk {
+    initialize_params {
+      # The boot disk must be set to the variable declared in Producer Portal
+      image = var.image
+    }
+  }
+
+  network_interface {
+    network = "default"
+  }
+
+  network_interface {
+    network = var.other_nic
+  }
+}
+

examples/terraform/complex_cli_only/variables.tf

@@ -0,0 +1,26 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# The variable "image" is declared in Producer Portal
+variable "image" {
+  # Set the default value to your image. Marketplace will overwrite this value
+  # to a Marketplace owned image on publishing the product
+  default = "projects/<partner-project>/global/images/<image-name>"
+}
+
+# Specifies a network interface that this module assumes already exists
+variable "other_nic" {
+  type = string
+}
+

examples/terraform/simple_cli_only/README.md

@@ -5,12 +5,12 @@ for a Terraform **CLI Only** module
 To validate your module, Marketplace will execute:
 
 ```
-terraform -chdir=examples/marketplace_test init
-terraform -chdir=examples/marketplace_test plan -var project=<test-project>
+terraform init
+terraform plan -var-file=marketplace_test.tfvars -var project_id=<test-project>
 ```
 
-The module in examples/marketplace_test must reference your root module (i.e.
-the module in the root directory)
+The `marketplace_test.tfvars` can be used to set variables to default values for
+testing only purposes.
 
 For a Marketplace Partner to reuse this module, they must:
 

examples/terraform/simple_cli_only/main.tf

@@ -12,15 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+provider "google" {
+  project = var.project_id
+}
+
 resource "google_compute_instance" "default" {
   name         = "example"
   machine_type = "e2-medium"
   zone         = "us-central1-a"
 
   boot_disk {
     initialize_params {
-       # The boot disk must be set to the variable declared in Producer Portal
-       image = var.image
+      # The boot disk must be set to the variable declared in Producer Portal
+      image = var.image
     }
   }
 

examples/terraform/simple_cli_only/marketplace_test.tfvars

@@ -0,0 +1,2 @@
+# zone variable must be set because no default value was specified in "variables.tf"
+zone = "us-central1-a"

examples/terraform/simple_cli_only/variables.tf

@@ -14,7 +14,17 @@
 
 # The variable "image" is declared in Producer Portal
 variable "image" {
+  type = string
   # Set the default value to your image. Marketplace will overwrite this value
   # to a Marketplace owned image on publishing the product
   default = "projects/<partner-project>/global/images/<image-name>"
 }
+
+# Project Id is required for Marketplace validation
+variable "project_id" {
+  type = string
+}
+
+variable "zone" {
+  type = string
+}