fix: Restore warning on unused config option(s) (#12063)

config/config.go

@@ -693,8 +693,17 @@ func (c *Config) probeParser(table *ast.Table) bool {
 	var dataformat string
 	c.getFieldString(table, "data_format", &dataformat)
 
-	_, ok := parsers.Parsers[dataformat]
+	creator, ok := parsers.Parsers[dataformat]
-	return ok
+	if !ok {
+		return false
+	}
+
+	// Try to parse the options to detect if any of them is misspelled
+	// We don't actually use the parser, so no need to check the error.
+	parser := creator("")
+	_ = c.toml.UnmarshalTable(table, parser)
+
+	return true
 }
 
 func (c *Config) addParser(parentcategory, parentname string, table *ast.Table) (*models.RunningParser, error) {
@@ -754,6 +763,7 @@ func (c *Config) addProcessor(name string, table *ast.Table) error {
 	// for the input both need to miss the entry. We count the
 	// missing entries at the end.
 	missCount := make(map[string]int)
+	missCountThreshold := 0
 	c.setLocalMissingTomlFieldTracker(missCount)
 	defer c.resetMissingTomlFieldTracker()
 
@@ -772,6 +782,7 @@ func (c *Config) addProcessor(name string, table *ast.Table) error {
 	// it can accept arbitrary data-formats, so build the requested parser and
 	// set it.
 	if t, ok := processor.(telegraf.ParserPlugin); ok {
+		missCountThreshold = 2
 		parser, err := c.addParser("processors", name, table)
 		if err != nil {
 			return fmt.Errorf("adding parser failed: %w", err)
@@ -780,6 +791,7 @@ func (c *Config) addProcessor(name string, table *ast.Table) error {
 	}
 
 	if t, ok := processor.(telegraf.ParserFuncPlugin); ok {
+		missCountThreshold = 2
 		if !c.probeParser(table) {
 			return errors.New("parser not found")
 		}
@@ -804,6 +816,16 @@ func (c *Config) addProcessor(name string, table *ast.Table) error {
 	rf = models.NewRunningProcessor(streamingProcessor, processorConfig)
 	c.AggProcessors = append(c.AggProcessors, rf)
 
+	// Check the number of misses against the threshold
+	for key, count := range missCount {
+		if count <= missCountThreshold {
+			continue
+		}
+		if err := c.missingTomlField(nil, key); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
@@ -884,6 +906,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 	// for the input both need to miss the entry. We count the
 	// missing entries at the end.
 	missCount := make(map[string]int)
+	missCountThreshold := 0
 	c.setLocalMissingTomlFieldTracker(missCount)
 	defer c.resetMissingTomlFieldTracker()
 
@@ -902,6 +925,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 	// If the input has a SetParser or SetParserFunc function, it can accept
 	// arbitrary data-formats, so build the requested parser and set it.
 	if t, ok := input.(telegraf.ParserPlugin); ok {
+		missCountThreshold = 1
 		parser, err := c.addParser("inputs", name, table)
 		if err != nil {
 			return fmt.Errorf("adding parser failed: %w", err)
@@ -912,6 +936,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 	// Keep the old interface for backward compatibility
 	if t, ok := input.(parsers.ParserInput); ok {
 		// DEPRECATED: Please switch your plugin to telegraf.ParserPlugin.
+		missCountThreshold = 1
 		parser, err := c.addParser("inputs", name, table)
 		if err != nil {
 			return fmt.Errorf("adding parser failed: %w", err)
@@ -920,6 +945,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 	}
 
 	if t, ok := input.(telegraf.ParserFuncPlugin); ok {
+		missCountThreshold = 1
 		if !c.probeParser(table) {
 			return errors.New("parser not found")
 		}
@@ -930,6 +956,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 
 	if t, ok := input.(parsers.ParserFuncInput); ok {
 		// DEPRECATED: Please switch your plugin to telegraf.ParserFuncPlugin.
+		missCountThreshold = 1
 		if !c.probeParser(table) {
 			return errors.New("parser not found")
 		}
@@ -963,7 +990,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 
 	// Check the number of misses against the threshold
 	for key, count := range missCount {
-		if count <= 1 {
+		if count <= missCountThreshold {
 			continue
 		}
 		if err := c.missingTomlField(nil, key); err != nil {
@@ -1243,11 +1270,27 @@ func (c *Config) missingTomlField(_ reflect.Type, key string) error {
 }
 
 func (c *Config) setLocalMissingTomlFieldTracker(counter map[string]int) {
-	f := func(_ reflect.Type, key string) error {
+	f := func(t reflect.Type, key string) error {
-		if c, ok := counter[key]; ok {
+		// Check if we are in a root element that might share options among
-			counter[key] = c + 1
+		// each other. Those root elements are plugins of all types.
-		} else {
+		// All other elements are subtables of their respective plugin and
+		// should just be hit once anyway. Therefore, we mark them with a
+		// high number to handle them correctly later.
+		pt := reflect.PtrTo(t)
+		root := pt.Implements(reflect.TypeOf((*telegraf.Input)(nil)).Elem())
+		root = root || pt.Implements(reflect.TypeOf((*telegraf.ServiceInput)(nil)).Elem())
+		root = root || pt.Implements(reflect.TypeOf((*telegraf.Output)(nil)).Elem())
+		root = root || pt.Implements(reflect.TypeOf((*telegraf.Aggregator)(nil)).Elem())
+		root = root || pt.Implements(reflect.TypeOf((*telegraf.Processor)(nil)).Elem())
+		root = root || pt.Implements(reflect.TypeOf((*telegraf.Parser)(nil)).Elem())
+
+		c, ok := counter[key]
+		if !root {
+			counter[key] = 100
+		} else if !ok {
 			counter[key] = 1
+		} else {
+			counter[key] = c + 1
 		}
 		return nil
 	}

config/config_test.go

@@ -285,10 +285,70 @@ func TestConfig_LoadSpecialTypes(t *testing.T) {
 }
 
 func TestConfig_FieldNotDefined(t *testing.T) {
-	c := NewConfig()
+	tests := []struct {
-	err := c.LoadConfig("./testdata/invalid_field.toml")
+		name     string
-	require.Error(t, err, "invalid field name")
+		filename string
-	require.Equal(t, "error loading config file ./testdata/invalid_field.toml: plugin inputs.http_listener_v2: line 1: configuration specified the fields [\"not_a_field\"], but they weren't used", err.Error())
+		expected string
+	}{
+		{
+			name:     "in input plugin without parser",
+			filename: "./testdata/invalid_field.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in input plugin with parser",
+			filename: "./testdata/invalid_field_with_parser.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in input plugin with parser func",
+			filename: "./testdata/invalid_field_with_parserfunc.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in parser of input plugin",
+			filename: "./testdata/invalid_field_in_parser_table.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in parser of input plugin with parser-func",
+			filename: "./testdata/invalid_field_in_parserfunc_table.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in processor plugin without parser",
+			filename: "./testdata/invalid_field_processor.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in processor plugin with parser",
+			filename: "./testdata/invalid_field_processor_with_parser.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in processor plugin with parser func",
+			filename: "./testdata/invalid_field_processor_with_parserfunc.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in parser of processor plugin",
+			filename: "./testdata/invalid_field_processor_in_parser_table.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+		{
+			name:     "in parser of processor plugin with parser-func",
+			filename: "./testdata/invalid_field_processor_in_parserfunc_table.toml",
+			expected: `line 1: configuration specified the fields ["not_a_field"], but they weren't used`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := NewConfig()
+			err := c.LoadConfig(tt.filename)
+			require.ErrorContains(t, err, tt.expected)
+		})
+	}
 }
 
 func TestConfig_WrongFieldType(t *testing.T) {
@@ -843,6 +903,36 @@ func (m *MockupInputPlugin) SetParser(parser telegraf.Parser) {
 	m.parser = parser
 }
 
+/*** Mockup INPUT plugin with ParserFunc interface ***/
+type MockupInputPluginParserFunc struct {
+	parserFunc telegraf.ParserFunc
+}
+
+func (m *MockupInputPluginParserFunc) SampleConfig() string {
+	return "Mockup test input plugin"
+}
+func (m *MockupInputPluginParserFunc) Gather(_ telegraf.Accumulator) error {
+	return nil
+}
+func (m *MockupInputPluginParserFunc) SetParserFunc(pf telegraf.ParserFunc) {
+	m.parserFunc = pf
+}
+
+/*** Mockup INPUT plugin without ParserFunc interface ***/
+type MockupInputPluginParserOnly struct {
+	parser telegraf.Parser
+}
+
+func (m *MockupInputPluginParserOnly) SampleConfig() string {
+	return "Mockup test input plugin"
+}
+func (m *MockupInputPluginParserOnly) Gather(_ telegraf.Accumulator) error {
+	return nil
+}
+func (m *MockupInputPluginParserOnly) SetParser(p telegraf.Parser) {
+	m.parser = p
+}
+
 /*** Mockup PROCESSOR plugin for testing to avoid cyclic dependencies ***/
 type MockupProcessorPluginParser struct {
 	Parser     telegraf.Parser
@@ -871,6 +961,73 @@ func (m *MockupProcessorPluginParser) SetParserFunc(f telegraf.ParserFunc) {
 	m.ParserFunc = f
 }
 
+/*** Mockup PROCESSOR plugin without parser ***/
+type MockupProcessorPlugin struct{}
+
+func (m *MockupProcessorPlugin) Start(_ telegraf.Accumulator) error {
+	return nil
+}
+func (m *MockupProcessorPlugin) Stop() error {
+	return nil
+}
+func (m *MockupProcessorPlugin) SampleConfig() string {
+	return "Mockup test processor plugin with parser"
+}
+func (m *MockupProcessorPlugin) Apply(_ ...telegraf.Metric) []telegraf.Metric {
+	return nil
+}
+func (m *MockupProcessorPlugin) Add(_ telegraf.Metric, _ telegraf.Accumulator) error {
+	return nil
+}
+
+/*** Mockup PROCESSOR plugin with parser ***/
+type MockupProcessorPluginParserOnly struct {
+	Parser telegraf.Parser
+}
+
+func (m *MockupProcessorPluginParserOnly) Start(_ telegraf.Accumulator) error {
+	return nil
+}
+func (m *MockupProcessorPluginParserOnly) Stop() error {
+	return nil
+}
+func (m *MockupProcessorPluginParserOnly) SampleConfig() string {
+	return "Mockup test processor plugin with parser"
+}
+func (m *MockupProcessorPluginParserOnly) Apply(_ ...telegraf.Metric) []telegraf.Metric {
+	return nil
+}
+func (m *MockupProcessorPluginParserOnly) Add(_ telegraf.Metric, _ telegraf.Accumulator) error {
+	return nil
+}
+func (m *MockupProcessorPluginParserOnly) SetParser(parser telegraf.Parser) {
+	m.Parser = parser
+}
+
+/*** Mockup PROCESSOR plugin with parser-function ***/
+type MockupProcessorPluginParserFunc struct {
+	Parser telegraf.ParserFunc
+}
+
+func (m *MockupProcessorPluginParserFunc) Start(_ telegraf.Accumulator) error {
+	return nil
+}
+func (m *MockupProcessorPluginParserFunc) Stop() error {
+	return nil
+}
+func (m *MockupProcessorPluginParserFunc) SampleConfig() string {
+	return "Mockup test processor plugin with parser"
+}
+func (m *MockupProcessorPluginParserFunc) Apply(_ ...telegraf.Metric) []telegraf.Metric {
+	return nil
+}
+func (m *MockupProcessorPluginParserFunc) Add(_ telegraf.Metric, _ telegraf.Accumulator) error {
+	return nil
+}
+func (m *MockupProcessorPluginParserFunc) SetParserFunc(pf telegraf.ParserFunc) {
+	m.Parser = pf
+}
+
 /*** Mockup OUTPUT plugin for testing to avoid cyclic dependencies ***/
 type MockupOuputPlugin struct {
 	URL             string            `toml:"url"`
@@ -903,6 +1060,12 @@ func init() {
 	inputs.Add("parser_test_old", func() telegraf.Input {
 		return &MockupInputPluginParserOld{}
 	})
+	inputs.Add("parser", func() telegraf.Input {
+		return &MockupInputPluginParserOnly{}
+	})
+	inputs.Add("parser_func", func() telegraf.Input {
+		return &MockupInputPluginParserFunc{}
+	})
 	inputs.Add("exec", func() telegraf.Input {
 		return &MockupInputPlugin{Timeout: Duration(time.Second * 5)}
 	})
@@ -916,10 +1079,19 @@ func init() {
 		return &MockupInputPlugin{}
 	})
 
-	// Register the mockup output plugin for the required names
+	// Register the mockup processor plugin for the required names
 	processors.Add("parser_test", func() telegraf.Processor {
 		return &MockupProcessorPluginParser{}
 	})
+	processors.Add("processor", func() telegraf.Processor {
+		return &MockupProcessorPlugin{}
+	})
+	processors.Add("processor_parser", func() telegraf.Processor {
+		return &MockupProcessorPluginParserOnly{}
+	})
+	processors.Add("processor_parserfunc", func() telegraf.Processor {
+		return &MockupProcessorPluginParserFunc{}
+	})
 
 	// Register the mockup output plugin for the required names
 	outputs.Add("azure_monitor", func() telegraf.Output {

config/testdata/invalid_field_in_parser_table.toml

@@ -0,0 +1,5 @@
+[[inputs.parser]]
+  data_format = "xpath_json"
+
+  [[inputs.parser.xpath]]
+    not_a_field = true

config/testdata/invalid_field_in_parserfunc_table.toml

@@ -0,0 +1,5 @@
+[[inputs.parser_func]]
+  data_format = "xpath_json"
+
+  [[inputs.parser_func.xpath]]
+    not_a_field = true

config/testdata/invalid_field_processor.toml

@@ -0,0 +1,2 @@
+[[processors.processor]]
+  not_a_field = true

config/testdata/invalid_field_processor_in_parser.toml

@@ -0,0 +1,3 @@
+[[processors.processor_parser]]
+  not_a_field = true
+  data_format = "influx"

config/testdata/invalid_field_processor_in_parser_table.toml

@@ -0,0 +1,5 @@
+[[processors.processor_parser]]
+  data_format = "xpath_json"
+
+  [[processors.processor_parser.xpath]]
+    not_a_field = true

config/testdata/invalid_field_processor_in_parserfunc.toml

@@ -0,0 +1,3 @@
+[[processors.processor_parserfunc]]
+  not_a_field = true
+  data_format = "influx"

config/testdata/invalid_field_processor_in_parserfunc_table.toml

@@ -0,0 +1,5 @@
+[[inputs.parser_func]]
+  data_format = "xpath_json"
+
+  [[inputs.parser_func.xpath]]
+    not_a_field = true

config/testdata/invalid_field_processor_with_parser.toml

@@ -0,0 +1,3 @@
+[[processors.processor_parser]]
+  not_a_field = true
+  data_format = "influx"

config/testdata/invalid_field_processor_with_parserfunc.toml

@@ -0,0 +1,3 @@
+[[processors.processor_parserfunc]]
+  not_a_field = true
+  data_format = "influx"

config/testdata/invalid_field_with_parser.toml

@@ -0,0 +1,3 @@
+[[inputs.parser]]
+  not_a_field = true
+  data_format = "influx"

config/testdata/invalid_field_with_parserfunc.toml

@@ -0,0 +1,3 @@
+[[inputs.parser_func]]
+  not_a_field = true
+  data_format = "influx"