Virtual field for google_cloud_run_service revision names (#3306)

* Add `autogenerate_revision_name` virtual field to `google_cloud_run_service`

* Add field to examples

products/cloudrun/terraform.yaml

@@ -82,6 +82,8 @@ overrides: !ruby/object:Overrides::ResourceOverrides
           cloud_run_sql_name: "cloudrun-sql"
         test_env_vars:
           project: :PROJECT_NAME
+        ignore_read_extra:
+          - "autogenerate_revision_name"
       - !ruby/object:Provider::Terraform::Examples
         name: "cloud_run_service_noauth"
         primary_resource_id: "default"
@@ -98,9 +100,22 @@ overrides: !ruby/object:Overrides::ResourceOverrides
           cloud_run_service_name: "cloudrun-srv"
         test_env_vars:
           project: :PROJECT_NAME
+        ignore_read_extra:
+          - "autogenerate_revision_name"
+    virtual_fields:
+      - !ruby/object:Provider::Terraform::VirtualFields
+        name: 'autogenerate_revision_name'
+        description: |
+          If set to `true`, the revision name (template.metadata.name) will be omitted and 
+          autogenerated by Cloud Run. This cannot be set to `true` while `template.metadata.name` 
+          is also set. 
+          (For legacy support, if `template.metadata.name` is unset in state while
+          this field is set to false, the revision name will still autogenerate.)
     custom_code: !ruby/object:Provider::Terraform::CustomCode
       encoder: 'templates/terraform/encoders/cloud_run_service.go.erb'
       decoder: 'templates/terraform/decoders/cloud_run.go.erb'
+      constants: templates/terraform/constants/cloud_run_service.go.erb
+      resource_definition: templates/terraform/resource_definition/cloud_run_service.go.erb
     properties:
       name: !ruby/object:Overrides::Terraform::PropertyOverride
         required: true
@@ -116,6 +131,7 @@ overrides: !ruby/object:Overrides::ResourceOverrides
       spec.template.metadata: !ruby/object:Overrides::Terraform::PropertyOverride
         default_from_api: true
       spec.template.metadata.name: !ruby/object:Overrides::Terraform::PropertyOverride
+        custom_expand: 'templates/terraform/custom_expand/cloud_run_service_revision_name.erb'
         default_from_api: true
       spec.template.metadata.annotations: !ruby/object:Overrides::Terraform::PropertyOverride
         default_from_api: true

templates/terraform/constants/cloud_run_service.go.erb

@@ -0,0 +1,7 @@
+func revisionNameCustomizeDiff(diff *schema.ResourceDiff, v interface{}) error {
+	autogen := diff.Get("autogenerate_revision_name").(bool)
+	if autogen && diff.HasChange("template.0.metadata.0.name") {
+		return fmt.Errorf("google_cloud_run_service: `template.metadata.name` cannot be set while `autogenerate_revision_name` is true. Please remove the field or set `autogenerate_revision_name` to false.")
+	}
+	return nil
+}

templates/terraform/custom_expand/cloud_run_service_revision_name.erb

@@ -0,0 +1,6 @@
+func expand<%= prefix -%><%= titlelize_property(property) -%>(v interface{}, d TerraformResourceData, config *Config) (interface{}, error) {
+	if d.Get("autogenerate_revision_name") == true {
+		return nil, nil
+	}
+	return v, nil
+}

templates/terraform/examples/cloud_run_service_multiple_environment_variables.tf.erb

@@ -22,4 +22,5 @@ resource "google_cloud_run_service" "<%= ctx[:primary_resource_id] %>" {
     percent         = 100
     latest_revision = true
   }
+  autogenerate_revision_name = true
 }

templates/terraform/examples/cloud_run_service_sql.tf.erb

@@ -17,6 +17,7 @@ resource "google_cloud_run_service" "<%= ctx[:primary_resource_id] %>" {
       }
     }
   }
+  autogenerate_revision_name = true
 }
 
 resource "google_sql_database_instance" "instance" {

templates/terraform/resource_definition/cloud_run_service.go.erb

@@ -0,0 +1,16 @@
+<%# The license inside this block applies to this file.
+	# Copyright 2020 Google Inc.
+	# 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.
+-%>
+SchemaVersion: 1,
+CustomizeDiff: revisionNameCustomizeDiff,