fix(parsers.json_v2): Properly handle optional fields

plugins/parsers/json_v2/parser.go

@@ -210,8 +210,8 @@ func (p *Parser) processMetric(input []byte, data []DataSet, tag bool, timestamp
 			return nil, fmt.Errorf("GJSON path is required")
 		}
 		result := gjson.GetBytes(input, c.Path)
-		if skip, err := p.checkResult(result, c.Path, c.Optional); err != nil {
-			if skip {
+		if err := p.checkResult(result, c.Path); err != nil {
+			if c.Optional {
 				continue
 			}
 			return nil, err
@@ -456,8 +456,8 @@ func (p *Parser) processObjects(input []byte, objects []Object, timestamp time.T
 		}
 
 		result := gjson.GetBytes(input, c.Path)
-		if skip, err := p.checkResult(result, c.Path, c.Optional); err != nil {
-			if skip {
+		if err := p.checkResult(result, c.Path); err != nil {
+			if c.Optional {
 				continue
 			}
 			return nil, err
@@ -467,8 +467,8 @@ func (p *Parser) processObjects(input []byte, objects []Object, timestamp time.T
 		for _, f := range c.FieldPaths {
 			var r PathResult
 			r.result = gjson.GetBytes(scopedJSON, f.Path)
-			if skip, err := p.checkResult(r.result, f.Path, f.Optional); err != nil {
-				if skip {
+			if err := p.checkResult(r.result, f.Path); err != nil {
+				if f.Optional {
 					continue
 				}
 				return nil, err
@@ -480,8 +480,8 @@ func (p *Parser) processObjects(input []byte, objects []Object, timestamp time.T
 		for _, f := range c.TagPaths {
 			var r PathResult
 			r.result = gjson.GetBytes(scopedJSON, f.Path)
-			if skip, err := p.checkResult(r.result, f.Path, f.Optional); err != nil {
-				if skip {
+			if err := p.checkResult(r.result, f.Path); err != nil {
+				if f.Optional {
 					continue
 				}
 				return nil, err
@@ -700,18 +700,14 @@ func (p *Parser) convertType(input gjson.Result, desiredType string, name string
 	return input.Value(), nil
 }
 
-func (p *Parser) checkResult(result gjson.Result, path string, optional bool) (bool, error) {
+// Check if gjson result exists and return error if it does not
+func (p *Parser) checkResult(result gjson.Result, path string) error {
 	if !result.Exists() {
-		if optional {
-			// If path is marked as optional don't error if path doesn't return a result
-			p.Log.Debugf("the path %q doesn't exist", path)
-			return true, nil
-		}
-
-		return false, fmt.Errorf("the path %q doesn't exist", path)
+		p.Log.Debugf("the path %q doesn't exist", path)
+		return fmt.Errorf("the path %q doesn't exist", path)
 	}
 
-	return false, nil
+	return nil
 }
 
 func init() {

plugins/parsers/json_v2/testdata/nested_objects_optional/expected.out

@@ -0,0 +1,5 @@
+file,datatype=float,name=inlet-1/temperature value_f=0.20791169081775931 1695679023000000000
+file,datatype=float value_f=-0.3090169943749477,name="inlet-1/temperature" 1695679077000000000
+file,datatype=string value_s="-0.3090169943749477",name="inlet-3/flow" 1695679077000000000
+file,datatype=int value_i=95i,name="inlet-2/temperature" 1695679077000000000
+file,datatype=bool value_b=true,name="inlet-2/flow" 1695679077000000000

plugins/parsers/json_v2/testdata/nested_objects_optional/nested_objects_nest.json

@@ -0,0 +1,25 @@
+{
+    "timestamp": 1695679077118.0,
+    "metrics": [
+        {
+            "value": -0.3090169943749477,
+            "name": "inlet-1/temperature",
+            "datatype": "float"
+        },
+        {
+            "value": 95,
+            "name": "inlet-2/temperature",
+            "datatype": "int"
+        },
+        {
+            "value": true,
+            "name": "inlet-2/flow",
+            "datatype": "bool"
+        },
+        {
+            "value": "-0.3090169943749477",
+            "name": "inlet-3/flow",
+            "datatype": "string"
+        }
+    ]
+}

plugins/parsers/json_v2/testdata/nested_objects_optional/nested_objects_single.json

@@ -0,0 +1,6 @@
+{
+    "timestamp": 1695679022882.0,
+    "value": 0.20791169081775931,
+    "name": "inlet-1/temperature",
+    "datatype": "float"
+}

plugins/parsers/json_v2/testdata/nested_objects_optional/telegraf.conf

@@ -0,0 +1,58 @@
+# Example taken from: https://github.com/influxdata/telegraf/issues/13990
+
+# Parse String types from JSON
+[[inputs.file]]
+
+    files = ["./testdata/nested_objects_optional/nested_objects_single.json", "./testdata/nested_objects_optional/nested_objects_nest.json"]
+    data_format = "json_v2"
+
+  [[inputs.file.json_v2]]
+    timestamp_path = 'timestamp'
+    timestamp_format = 'unix_ms'
+
+    [[inputs.file.json_v2.tag]]
+      path = 'name'
+      optional = true
+    [[inputs.file.json_v2.tag]]
+      path = 'datatype'
+      optional = true
+    [[inputs.file.json_v2.field]]
+      path = 'value'
+      rename = 'value_f'
+      optional = true
+
+    [[inputs.file.json_v2.object]]
+      path = 'metrics.#(datatype=="float")#'
+      optional = true
+      tags = ['datatype']
+      [inputs.file.json_v2.object.renames]
+        value = 'value_f'
+      [inputs.file.json_v2.object.fields]
+        value = 'float'
+
+    [[inputs.file.json_v2.object]]
+      path = 'metrics.#(datatype=="string")#'
+      optional = true
+      tags = ['datatype']
+      [inputs.file.json_v2.object.renames]
+        value = 'value_s'
+      [inputs.file.json_v2.object.fields]
+        value = 'string'
+
+    [[inputs.file.json_v2.object]]
+      path = 'metrics.#(datatype=="int")#'
+      optional = true
+      tags = ['datatype']
+      [inputs.file.json_v2.object.renames]
+        value = 'value_i'
+      [inputs.file.json_v2.object.fields]
+        value = 'int'
+
+    [[inputs.file.json_v2.object]]
+      path = 'metrics.#(datatype=="bool")#'
+      optional = true
+      tags = ['datatype']
+      [inputs.file.json_v2.object.renames]
+        value = 'value_b'
+      [inputs.file.json_v2.object.fields]
+        value = 'bool'