external name: use function in the config directly instead of generating the call

pkg/config/common.go

@@ -0,0 +1,40 @@
+/*
+Copyright 2021 The Crossplane Authors.
+
+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.
+*/
+
+package config
+
+// Common ExternalName configurations.
+var (
+	// NameAsIdentifier uses "name" field in the arguments as the identifier of
+	// the resource.
+	NameAsIdentifier = ExternalName{
+		SetIdentifierArgumentFn: func(base map[string]interface{}, name string) {
+			base["name"] = name
+		},
+		OmittedFields: []string{
+			"name",
+			"name_prefix",
+		},
+	}
+
+	// IdentifierFromProvider is used in resources whose identifier is assigned by
+	// the remote client, such as AWS VPC where it gets an identifier like
+	// vpc-2213das instead of letting user choose a name.
+	IdentifierFromProvider = ExternalName{
+		SetIdentifierArgumentFn: NopSetIdentifierArgument,
+		DisableNameInitializer:  true,
+	}
+)

pkg/config/resource.go

@@ -18,12 +18,12 @@ package config
 
 import "github.com/imdario/mergo"
 
-// SetNameAttributeFn sets the name of the resource in Terraform attributes map.
-type SetNameAttributeFn func(base map[string]interface{}, name string)
+// SetIdentifierArgumentFn sets the name of the resource in Terraform attributes map.
+type SetIdentifierArgumentFn func(base map[string]interface{}, name string)
 
-// NopSetNameAttribute does nothing. It's useful for cases where the external
+// NopSetIdentifierArgument does nothing. It's useful for cases where the external
 // name is calculated by provider and doesn't have any effect on spec fields.
-func NopSetNameAttribute(_ map[string]interface{}, _ string) {}
+func NopSetIdentifierArgument(_ map[string]interface{}, _ string) {}
 
 // ResourceOption allows setting optional fields of a Resource object.
 type ResourceOption func(*Resource)
@@ -43,7 +43,7 @@ func NewResource(version, kind, terraformResourceType string, opts ...ResourceOp
 		TerraformResourceType: terraformResourceType,
 		TerraformIDFieldName:  "id",
 		ExternalName: ExternalName{
-			SetNameAttributeFn: NopSetNameAttribute,
+			SetIdentifierArgumentFn: NopSetIdentifierArgument,
 		},
 	}
 	for _, f := range opts {
@@ -56,9 +56,9 @@ func NewResource(version, kind, terraformResourceType string, opts ...ResourceOp
 // such as removal of those fields from spec schema and calling Configure function
 // to fill attributes with information given in external name.
 type ExternalName struct {
-	// SetNameAttributeFn sets the name of the resource in Terraform attribute
+	// SetIdentifierArgumentFn sets the name of the resource in Terraform argument
 	// map.
-	SetNameAttributeFn SetNameAttributeFn
+	SetIdentifierArgumentFn SetIdentifierArgumentFn
 
 	// OmittedFields are the ones you'd like to be removed from the schema since
 	// they are specified via external name. You can omit only the top level fields.

pkg/terraform/files.go

@@ -74,8 +74,8 @@ func NewFileProducer(ctx context.Context, client resource.SecretClient, dir stri
 		return nil, errors.Wrap(err, "cannot get sensitive parameters")
 	}
 	// TODO(muvaf): Once we have automatic defaulting, remove this if check.
-	if fp.Config.ExternalName.SetNameAttributeFn != nil {
-		fp.Config.ExternalName.SetNameAttributeFn(params, meta.GetExternalName(tr))
+	if fp.Config.ExternalName.SetIdentifierArgumentFn != nil {
+		fp.Config.ExternalName.SetIdentifierArgumentFn(params, meta.GetExternalName(tr))
 	}
 	fp.parameters = params