fallback to region from redis location_id when region isn't specified

products/redis/terraform.yaml

@@ -21,6 +21,8 @@ overrides: !ruby/object:Overrides::ResourceOverrides
     autogen_async: true
     id_format: "{{project}}/{{region}}/{{name}}"
     import_format: ["projects/{{project}}/locations/{{region}}/instances/{{name}}"]
+    custom_code: !ruby/object:Provider::Terraform::CustomCode
+      encoder: templates/terraform/encoders/redis_location_id_for_fallback_zone.go.erb
     examples:
       - !ruby/object:Provider::Terraform::Examples
         name: "redis_instance_basic"

templates/terraform/encoders/redis_location_id_for_fallback_zone.go.erb

@@ -0,0 +1,21 @@
+<%# The license inside this block applies to this file.
+	# Copyright 2019 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.
+-%>
+config := meta.(*Config)
+region, err := getRegionFromSchema("region", "location_id", d, config)
+if err != nil {
+	return nil, err
+}
+d.Set("region", region)
+return obj, nil

third_party/terraform/tests/resource_redis_instance_test.go

@@ -38,6 +38,38 @@ func TestAccRedisInstance_update(t *testing.T) {
 	})
 }
 
+func TestAccRedisInstance_regionFromLocation(t *testing.T) {
+	t.Parallel()
+
+	name := acctest.RandomWithPrefix("tf-test")
+
+	// Pick a zone that isn't in the provider-specified region so we know we
+	// didn't fall back to that one.
+	region := "us-west1"
+	zone := "us-west1-b"
+	if getTestRegionFromEnv() == "us-west1" {
+		region = "us-central1"
+		zone = "us-central1-a"
+	}
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckRedisInstanceDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccRedisInstance_regionFromLocation(name, zone),
+				Check:  resource.TestCheckResourceAttr("google_redis_instance.test", "region", region),
+			},
+			{
+				ResourceName:      "google_redis_instance.test",
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
 func testAccRedisInstance_update(name string) string {
 	return fmt.Sprintf(`
 resource "google_redis_instance" "test" {
@@ -76,3 +108,12 @@ resource "google_redis_instance" "test" {
 	}
 }`, name)
 }
+
+func testAccRedisInstance_regionFromLocation(name, zone string) string {
+	return fmt.Sprintf(`
+resource "google_redis_instance" "test" {
+	name           = "%s"
+	memory_size_gb = 1
+	location_id    = "%s"
+}`, name, zone)
+}