Add strict mode to JSON parser (#6536)

plugins/parsers/json/README.md

@@ -18,6 +18,10 @@ ignored unless specified in the `tag_key` or `json_string_fields` options.
   ## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md
   data_format = "json"
 
+  ## When strict is true and a JSON array is being parsed, all objects within the
+  ## array must be valid
+  strict = false
+
   ## Query is a GJSON path that specifies a specific chunk of JSON to be
   ## parsed, if not specified the whole document will be parsed.
   ##

plugins/parsers/json/parser.go

@@ -32,6 +32,7 @@ type Config struct {
 	TimeFormat   string
 	Timezone     string
 	DefaultTags  map[string]string
+	Strict       bool
 }
 
 type Parser struct {
@@ -44,6 +45,7 @@ type Parser struct {
 	timeFormat   string
 	timezone     string
 	defaultTags  map[string]string
+	strict       bool
 }
 
 func New(config *Config) (*Parser, error) {
@@ -62,6 +64,7 @@ func New(config *Config) (*Parser, error) {
 		timeFormat:   config.TimeFormat,
 		timezone:     config.Timezone,
 		defaultTags:  config.DefaultTags,
+		strict:       config.Strict,
 	}, nil
 }
 
@@ -73,8 +76,11 @@ func (p *Parser) parseArray(data []interface{}) ([]telegraf.Metric, error) {
 		case map[string]interface{}:
 			metrics, err := p.parseObject(v)
 			if err != nil {
+				if p.strict {
 					return nil, err
 				}
+				continue
+			}
 			results = append(results, metrics...)
 		default:
 			return nil, ErrWrongType

plugins/parsers/json/parser_test.go

@@ -17,6 +17,7 @@ const (
 	validJSONArrayMultiple = "[{\"a\": 5, \"b\": {\"c\": 6}}, {\"a\": 7, \"b\": {\"c\": 8}}]"
 	invalidJSON            = "I don't think this is JSON"
 	invalidJSON2           = "{\"a\": 5, \"b\": \"c\": 6}}"
+	mixedValidityJSON      = "[{\"a\": 5, \"time\": \"2006-01-02T15:04:05\"}, {\"a\": 2}]"
 )
 
 const validJSONTags = `
@@ -152,6 +153,41 @@ func TestParseInvalidJSON(t *testing.T) {
 	require.Error(t, err)
 }
 
+func TestParseJSONImplicitStrictness(t *testing.T) {
+	parserImplicitNoStrict, err := New(&Config{
+		MetricName: "json_test",
+		TimeKey:    "time",
+	})
+	require.NoError(t, err)
+
+	_, err = parserImplicitNoStrict.Parse([]byte(mixedValidityJSON))
+	require.NoError(t, err)
+}
+
+func TestParseJSONExplicitStrictnessFalse(t *testing.T) {
+	parserNoStrict, err := New(&Config{
+		MetricName: "json_test",
+		TimeKey:    "time",
+		Strict:     false,
+	})
+	require.NoError(t, err)
+
+	_, err = parserNoStrict.Parse([]byte(mixedValidityJSON))
+	require.NoError(t, err)
+}
+
+func TestParseJSONExplicitStrictnessTrue(t *testing.T) {
+	parserStrict, err := New(&Config{
+		MetricName: "json_test",
+		TimeKey:    "time",
+		Strict:     true,
+	})
+	require.NoError(t, err)
+
+	_, err = parserStrict.Parse([]byte(mixedValidityJSON))
+	require.Error(t, err)
+}
+
 func TestParseWithTagKeys(t *testing.T) {
 	// Test that strings not matching tag keys are ignored
 	parser, err := New(&Config{

plugins/parsers/registry.go

@@ -89,6 +89,9 @@ type Config struct {
 	// default timezone
 	JSONTimezone string `toml:"json_timezone"`
 
+	// Whether to continue if a JSON object can't be coerced
+	JSONStrict bool `toml:"json_strict"`
+
 	// Authentication file for collectd
 	CollectdAuthFile string `toml:"collectd_auth_file"`
 	// One of none (default), sign, or encrypt
@@ -164,6 +167,7 @@ func NewParser(config *Config) (Parser, error) {
 				TimeFormat:   config.JSONTimeFormat,
 				Timezone:     config.JSONTimezone,
 				DefaultTags:  config.DefaultTags,
+				Strict:       config.JSONStrict,
 			},
 		)
 	case "value":