fixed perma-diff on log_config.enable

.changelog/5324.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+compute: fixed perma-diff bug on `log_config.enable` of both `google_compute_backend_service` and `google_compute_region_backend_service`
+```

google/resource_compute_backend_service.go

@@ -30,6 +30,15 @@ import (
 	"google.golang.org/api/googleapi"
 )
 
+// suppress changes on sample_rate if log_config is set to disabled.
+func suppressWhenDisabled(k, old, new string, d *schema.ResourceData) bool {
+	_, n := d.GetChange("log_config.0.enable")
+	if isEmptyValue(reflect.ValueOf(n)) {
+		return true
+	}
+	return false
+}
+
 // Whether the backend is a global or regional NEG
 func isNegBackend(backend map[string]interface{}) bool {
 	backendGroup, ok := backend["group"]
@@ -652,8 +661,9 @@ If logging is enabled, logs will be exported to Stackdriver.`,
 							AtLeastOneOf: []string{"log_config.0.enable", "log_config.0.sample_rate"},
 						},
 						"sample_rate": {
-							Type:     schema.TypeFloat,
-							Optional: true,
+							Type:             schema.TypeFloat,
+							Optional:         true,
+							DiffSuppressFunc: suppressWhenDisabled,
 							Description: `This field can only be specified if logging is enabled for this backend service. The value of
 the field must be in [0, 1]. This configures the sampling rate of requests to the load balancer
 where 1.0 means all logged requests are reported and 0.0 means no logged requests are reported.
@@ -3525,7 +3535,7 @@ func expandComputeBackendServiceLogConfig(v interface{}, d TerraformResourceData
 	transformedEnable, err := expandComputeBackendServiceLogConfigEnable(original["enable"], d, config)
 	if err != nil {
 		return nil, err
-	} else if val := reflect.ValueOf(transformedEnable); val.IsValid() && !isEmptyValue(val) {
+	} else {
 		transformed["enable"] = transformedEnable
 	}
 

google/resource_compute_backend_service_test.go

@@ -583,15 +583,39 @@ func TestAccComputeBackendService_withLogConfig(t *testing.T) {
 		CheckDestroy: testAccCheckComputeBackendServiceDestroyProducer(t),
 		Steps: []resource.TestStep{
 			{
-				Config: testAccComputeBackendService_withLogConfig(serviceName, checkName, 0.7),
+				Config: testAccComputeBackendService_withLogConfig(serviceName, checkName, 0.7, true),
 			},
 			{
 				ResourceName:      "google_compute_backend_service.foobar",
 				ImportState:       true,
 				ImportStateVerify: true,
 			},
 			{
-				Config: testAccComputeBackendService_withLogConfig(serviceName, checkName, 0.4),
+				Config: testAccComputeBackendService_withLogConfig(serviceName, checkName, 0.4, true),
+			},
+			{
+				ResourceName:      "google_compute_backend_service.foobar",
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+			{
+				Config: testAccComputeBackendService_withLogConfig(serviceName, checkName, 0.4, false),
+			},
+			{
+				ResourceName:      "google_compute_backend_service.foobar",
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+			{
+				Config: testAccComputeBackendService_withLogConfig2(serviceName, checkName, false),
+			},
+			{
+				ResourceName:      "google_compute_backend_service.foobar",
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+			{
+				Config: testAccComputeBackendService_withLogConfig(serviceName, checkName, 0.7, false),
 			},
 			{
 				ResourceName:      "google_compute_backend_service.foobar",
@@ -1407,14 +1431,14 @@ resource "google_compute_instance_template" "foobar" {
 `, fr, proxy, backend, hc, urlmap)
 }
 
-func testAccComputeBackendService_withLogConfig(serviceName, checkName string, sampleRate float64) string {
+func testAccComputeBackendService_withLogConfig(serviceName, checkName string, sampleRate float64, enabled bool) string {
 	return fmt.Sprintf(`
 resource "google_compute_backend_service" "foobar" {
   name          = "%s"
   health_checks = [google_compute_http_health_check.zero.self_link]
 
   log_config {
-    enable      = true
+    enable      = %t
     sample_rate = %v
   }
 }
@@ -1425,5 +1449,25 @@ resource "google_compute_http_health_check" "zero" {
   check_interval_sec = 1
   timeout_sec        = 1
 }
-`, serviceName, sampleRate, checkName)
+`, serviceName, enabled, sampleRate, checkName)
+}
+
+func testAccComputeBackendService_withLogConfig2(serviceName, checkName string, enabled bool) string {
+	return fmt.Sprintf(`
+resource "google_compute_backend_service" "foobar" {
+  name          = "%s"
+  health_checks = [google_compute_http_health_check.zero.self_link]
+
+  log_config {
+	enable      = %t
+  }
+}
+
+resource "google_compute_http_health_check" "zero" {
+  name               = "%s"
+  request_path       = "/"
+  check_interval_sec = 1
+  timeout_sec        = 1
+}
+`, serviceName, enabled, checkName)
 }

google/resource_compute_region_backend_service.go

@@ -620,8 +620,9 @@ If logging is enabled, logs will be exported to Stackdriver.`,
 							AtLeastOneOf: []string{"log_config.0.enable", "log_config.0.sample_rate"},
 						},
 						"sample_rate": {
-							Type:     schema.TypeFloat,
-							Optional: true,
+							Type:             schema.TypeFloat,
+							Optional:         true,
+							DiffSuppressFunc: suppressWhenDisabled,
 							Description: `This field can only be specified if logging is enabled for this backend service. The value of
 the field must be in [0, 1]. This configures the sampling rate of requests to the load balancer
 where 1.0 means all logged requests are reported and 0.0 means no logged requests are reported.
@@ -3519,7 +3520,7 @@ func expandComputeRegionBackendServiceLogConfig(v interface{}, d TerraformResour
 	transformedEnable, err := expandComputeRegionBackendServiceLogConfigEnable(original["enable"], d, config)
 	if err != nil {
 		return nil, err
-	} else if val := reflect.ValueOf(transformedEnable); val.IsValid() && !isEmptyValue(val) {
+	} else {
 		transformed["enable"] = transformedEnable
 	}