[Bug fix] aws_lambda_function: Suppress false persistent diffs on log levels when logging_format = "JSON" and publish = true

.changelog/42660.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_lambda_function: Fixed an issue where persistent diffs appeared in log level arguments when `log_format` in `logging_config` was set to `JSON` and `publish = true`
+```

internal/service/lambda/function.go

@@ -1360,12 +1360,25 @@ func needsFunctionCodeUpdate(d sdkv2.ResourceDiffer) bool {
 		d.HasChange("architectures")
 }
 
+func hasChangeForLoggingConfigLogLevel(d sdkv2.ResourceDiffer, key string, logFormatHasChange bool) bool {
+	if d.HasChange(key) {
+		oldValue, newValue := d.GetChange(key)
+		suppressed := suppressLoggingConfigUnspecifiedLogLevelsPrimitive(key, oldValue.(string), newValue.(string), logFormatHasChange)
+		return !suppressed
+	} else {
+		return false
+	}
+}
+
 func needsFunctionConfigUpdate(d sdkv2.ResourceDiffer) bool {
 	return d.HasChange(names.AttrDescription) ||
 		d.HasChange("handler") ||
 		d.HasChange("file_system_config") ||
 		d.HasChange("image_config") ||
-		d.HasChange("logging_config") ||
+		d.HasChange("logging_config.0.log_format") ||
+		d.HasChange("logging_config.0.log_group") ||
+		hasChangeForLoggingConfigLogLevel(d, "logging_config.0.application_log_level", d.HasChange("logging_config.0.log_format")) ||
+		hasChangeForLoggingConfigLogLevel(d, "logging_config.0.system_log_level", d.HasChange("logging_config.0.log_format")) ||
 		d.HasChange("memory_size") ||
 		d.HasChange(names.AttrRole) ||
 		d.HasChange(names.AttrTimeout) ||
@@ -1544,7 +1557,11 @@ func flattenLoggingConfig(apiObject *awstypes.LoggingConfig) []map[string]any {
 
 // Suppress diff if log levels have not been specified, unless log_format has changed
 func suppressLoggingConfigUnspecifiedLogLevels(k, old, new string, d *schema.ResourceData) bool {
-	if d.HasChanges("logging_config.0.log_format") {
+	return suppressLoggingConfigUnspecifiedLogLevelsPrimitive(k, old, new, d.HasChanges("logging_config.0.log_format"))
+}
+
+func suppressLoggingConfigUnspecifiedLogLevelsPrimitive(k, old, new string, logFormatHasChanges bool) bool { //nolint:unparam
+	if logFormatHasChanges {
 		return false
 	}
 	if old != "" && new == "" {

internal/service/lambda/function_test.go

@@ -635,12 +635,12 @@ func TestAccLambdaFunction_versionedUpdate(t *testing.T) {
 				PreConfig: func() {
 					timeBeforeUpdate = time.Now()
 				},
-				Config: testAccFunctionConfig_versionedNodeJs20xRuntime(path, rName),
+				Config: testAccFunctionConfig_versionedNodeJs22xRuntime(path, rName),
 				Check: resource.ComposeTestCheckFunc(
 					testAccCheckFunctionExists(ctx, resourceName, &conf),
 					resource.TestCheckResourceAttr(resourceName, names.AttrVersion, versionUpdated),
 					acctest.CheckResourceAttrRegionalARN(ctx, resourceName, "qualified_arn", "lambda", fmt.Sprintf("function:%s:%s", rName, versionUpdated)),
-					resource.TestCheckResourceAttr(resourceName, "runtime", string(awstypes.RuntimeNodejs20x)),
+					resource.TestCheckResourceAttr(resourceName, "runtime", string(awstypes.RuntimeNodejs22x)),
 					func(s *terraform.State) error {
 						return testAccCheckAttributeIsDateAfter(s, resourceName, "last_modified", timeBeforeUpdate)
 					},
@@ -1251,6 +1251,104 @@ func TestAccLambdaFunction_loggingConfig(t *testing.T) {
 	})
 }
 
+func TestAccLambdaFunction_loggingConfigWithPublish(t *testing.T) {
+	ctx := acctest.Context(t)
+	var conf lambda.GetFunctionOutput
+	rName := sdkacctest.RandomWithPrefix(acctest.ResourcePrefix)
+	resourceName := "aws_lambda_function.test"
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.PreCheck(ctx, t) },
+		ErrorCheck:               acctest.ErrorCheck(t, names.LambdaServiceID),
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories,
+		CheckDestroy:             testAccCheckFunctionDestroy(ctx),
+
+		Steps: []resource.TestStep{
+			{
+				Config: testAccFunctionConfig_loggingConfigWithPublish(rName, "Text"),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckFunctionExists(ctx, resourceName, &conf),
+					resource.TestCheckResourceAttr(resourceName, "publish", acctest.CtTrue),
+					resource.TestCheckResourceAttr(resourceName, names.AttrVersion, "1"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.application_log_level", ""),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.log_format", "Text"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.system_log_level", ""),
+				),
+			},
+			{
+				ResourceName:            resourceName,
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"filename", "publish"},
+			},
+			{
+				Config: testAccFunctionConfig_loggingConfigWithPublish(rName, "JSON"),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckFunctionExists(ctx, resourceName, &conf),
+					resource.TestCheckResourceAttr(resourceName, "publish", acctest.CtTrue),
+					resource.TestCheckResourceAttr(resourceName, names.AttrVersion, "2"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.application_log_level", "INFO"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.log_format", "JSON"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.system_log_level", "INFO"),
+				),
+			},
+			{
+				Config:             testAccFunctionConfig_loggingConfigWithPublish(rName, "JSON"),
+				ExpectNonEmptyPlan: false,
+				PlanOnly:           true,
+			},
+			{
+				Config: testAccFunctionConfig_loggingConfigWithPublishUpdated1(rName, "JSON", "DEBUG"),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckFunctionExists(ctx, resourceName, &conf),
+					resource.TestCheckResourceAttr(resourceName, "publish", acctest.CtTrue),
+					resource.TestCheckResourceAttr(resourceName, names.AttrVersion, "3"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.application_log_level", "DEBUG"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.log_format", "JSON"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.system_log_level", "INFO"),
+				),
+			},
+			{
+				Config: testAccFunctionConfig_loggingConfigWithPublishUpdated2(rName, "JSON", "WARN"),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckFunctionExists(ctx, resourceName, &conf),
+					resource.TestCheckResourceAttr(resourceName, "publish", acctest.CtTrue),
+					resource.TestCheckResourceAttr(resourceName, names.AttrVersion, "4"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.application_log_level", "DEBUG"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.log_format", "JSON"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.system_log_level", "WARN"),
+				),
+			},
+			{
+				Config:             testAccFunctionConfig_loggingConfigWithPublish(rName, "JSON"),
+				ExpectNonEmptyPlan: false,
+				PlanOnly:           true,
+			},
+			{
+				Config: testAccFunctionConfig_loggingConfigWithPublish(rName, "Text"),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckFunctionExists(ctx, resourceName, &conf),
+					resource.TestCheckResourceAttr(resourceName, "publish", acctest.CtTrue),
+					resource.TestCheckResourceAttr(resourceName, names.AttrVersion, "5"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.application_log_level", ""),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.log_format", "Text"),
+					resource.TestCheckResourceAttr(resourceName, "logging_config.0.system_log_level", ""),
+				),
+			},
+			{
+				Config:             testAccFunctionConfig_loggingConfigWithPublish(rName, "Text"),
+				ExpectNonEmptyPlan: false,
+				PlanOnly:           true,
+			},
+		},
+	})
+}
+
 func TestAccLambdaFunction_tracing(t *testing.T) {
 	ctx := acctest.Context(t)
 	if testing.Short() {
@@ -2973,7 +3071,7 @@ resource "aws_lambda_function" "test" {
 `, fileName, rName, publish))
 }
 
-func testAccFunctionConfig_versionedNodeJs20xRuntime(fileName, rName string) string {
+func testAccFunctionConfig_versionedNodeJs22xRuntime(fileName, rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLambdaBase(rName, rName, rName),
 		fmt.Sprintf(`
@@ -2983,7 +3081,7 @@ resource "aws_lambda_function" "test" {
   publish       = true
   role          = aws_iam_role.iam_for_lambda.arn
   handler       = "exports.example"
-  runtime       = "nodejs20.x"
+  runtime       = "nodejs22.x"
 }
 `, fileName, rName))
 }
@@ -3385,6 +3483,65 @@ resource "aws_lambda_function" "test" {
 `, rName))
 }
 
+func testAccFunctionConfig_loggingConfigWithPublish(rName, logFormat string) string {
+	return acctest.ConfigCompose(
+		acctest.ConfigLambdaBase(rName, rName, rName),
+		fmt.Sprintf(`
+resource "aws_lambda_function" "test" {
+  filename      = "test-fixtures/lambdatest.zip"
+  function_name = %[1]q
+  role          = aws_iam_role.iam_for_lambda.arn
+  handler       = "exports.example"
+  runtime       = "nodejs20.x"
+  publish       = true
+
+  logging_config {
+    log_format = %[2]q
+  }
+}
+`, rName, logFormat))
+}
+
+func testAccFunctionConfig_loggingConfigWithPublishUpdated1(rName, logFormat, appLogLevel string) string {
+	return acctest.ConfigCompose(
+		acctest.ConfigLambdaBase(rName, rName, rName),
+		fmt.Sprintf(`
+resource "aws_lambda_function" "test" {
+  filename      = "test-fixtures/lambdatest.zip"
+  function_name = %[1]q
+  role          = aws_iam_role.iam_for_lambda.arn
+  handler       = "exports.example"
+  runtime       = "nodejs20.x"
+  publish       = true
+
+  logging_config {
+    log_format            = %[2]q
+    application_log_level = %[3]q
+  }
+}
+`, rName, logFormat, appLogLevel))
+}
+
+func testAccFunctionConfig_loggingConfigWithPublishUpdated2(rName, logFormat, sysLogLevel string) string {
+	return acctest.ConfigCompose(
+		acctest.ConfigLambdaBase(rName, rName, rName),
+		fmt.Sprintf(`
+resource "aws_lambda_function" "test" {
+  filename      = "test-fixtures/lambdatest.zip"
+  function_name = %[1]q
+  role          = aws_iam_role.iam_for_lambda.arn
+  handler       = "exports.example"
+  runtime       = "nodejs20.x"
+  publish       = true
+
+  logging_config {
+    log_format       = %[2]q
+    system_log_level = %[3]q
+  }
+}
+`, rName, logFormat, sysLogLevel))
+}
+
 func testAccFunctionConfig_tracing(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLambdaBase(rName, rName, rName),