feat: Migrate nagios parser to new style (#11402)

plugins/inputs/exec/exec.go

@@ -135,7 +135,7 @@ func (*Exec) SampleConfig() string {
 
 func (e *Exec) ProcessCommand(command string, acc telegraf.Accumulator, wg *sync.WaitGroup) {
 	defer wg.Done()
-	_, isNagios := e.parser.(*nagios.NagiosParser)
+	_, isNagios := e.parser.(*nagios.Parser)
 
 	out, errBuf, runErr := e.runner.Run(command, e.Environment, time.Duration(e.Timeout))
 	if !isNagios && runErr != nil {

plugins/parsers/all/all.go

@@ -11,6 +11,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/parsers/json"
 	_ "github.com/influxdata/telegraf/plugins/parsers/json_v2"
 	_ "github.com/influxdata/telegraf/plugins/parsers/logfmt"
+	_ "github.com/influxdata/telegraf/plugins/parsers/nagios"
 	_ "github.com/influxdata/telegraf/plugins/parsers/value"
 	_ "github.com/influxdata/telegraf/plugins/parsers/wavefront"
 	_ "github.com/influxdata/telegraf/plugins/parsers/xpath"

plugins/parsers/nagios/parser.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
+	"github.com/influxdata/telegraf/plugins/parsers"
 )
 
 // unknownExitCode is the nagios unknown status code
@@ -85,10 +86,11 @@ func AddState(runErr error, errMessage []byte, metrics []telegraf.Metric) []tele
 	return append(metrics, m)
 }
 
-type NagiosParser struct {
-	MetricName  string
-	DefaultTags map[string]string
+type Parser struct {
+	DefaultTags map[string]string `toml:"-"`
 	Log         telegraf.Logger   `toml:"-"`
+
+	metricName string
 }
 
 // Got from Alignak
@@ -98,16 +100,16 @@ var (
 	nagiosRegExp    = regexp.MustCompile(`^([^=]+)=([\d\.\-\+eE]+)([\w\/%]*);?([\d\.\-\+eE:~@]+)?;?([\d\.\-\+eE:~@]+)?;?([\d\.\-\+eE]+)?;?([\d\.\-\+eE]+)?;?\s*`)
 )
 
-func (p *NagiosParser) ParseLine(line string) (telegraf.Metric, error) {
+func (p *Parser) ParseLine(line string) (telegraf.Metric, error) {
 	metrics, err := p.Parse([]byte(line))
 	return metrics[0], err
 }
 
-func (p *NagiosParser) SetDefaultTags(tags map[string]string) {
+func (p *Parser) SetDefaultTags(tags map[string]string) {
 	p.DefaultTags = tags
 }
 
-func (p *NagiosParser) Parse(buf []byte) ([]telegraf.Metric, error) {
+func (p *Parser) Parse(buf []byte) ([]telegraf.Metric, error) {
 	ts := time.Now().UTC()
 
 	s := bufio.NewScanner(bytes.NewReader(buf))
@@ -308,3 +310,19 @@ func parseThreshold(threshold string) (min float64, max float64, err error) {
 
 	return min, max, err
 }
+
+func init() {
+	// Register parser
+	parsers.Add("nagios",
+		func(defaultMetricName string) telegraf.Parser {
+			return &Parser{metricName: defaultMetricName}
+		},
+	)
+}
+
+// InitFromConfig is a compatibility function to construct the parser the old way
+func (p *Parser) InitFromConfig(config *parsers.Config) error {
+	p.metricName = config.MetricName
+	p.DefaultTags = config.DefaultTags
+	return nil
+}

plugins/parsers/nagios/parser_test.go

@@ -215,8 +215,8 @@ func assertNagiosState(t *testing.T, m telegraf.Metric, f map[string]interface{}
 }
 
 func TestParse(t *testing.T) {
-	parser := NagiosParser{
-		MetricName: "nagios_test",
+	parser := Parser{
+		metricName: "nagios_test",
 	}
 
 	tests := []struct {

plugins/parsers/registry.go

@@ -6,7 +6,6 @@ import (
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/parsers/influx"
 	"github.com/influxdata/telegraf/plugins/parsers/influx/influx_upstream"
-	"github.com/influxdata/telegraf/plugins/parsers/nagios"
 	"github.com/influxdata/telegraf/plugins/parsers/prometheus"
 	"github.com/influxdata/telegraf/plugins/parsers/prometheusremotewrite"
 	"github.com/influxdata/telegraf/plugins/parsers/temporary/json_v2"
@@ -203,8 +202,6 @@ func NewParser(config *Config) (Parser, error) {
 		} else {
 			parser, err = NewInfluxParser()
 		}
-	case "nagios":
-		parser, err = NewNagiosParser()
 	case "prometheus":
 		parser, err = NewPrometheusParser(
 			config.DefaultTags,
@@ -230,10 +227,6 @@ func NewParser(config *Config) (Parser, error) {
 	return parser, err
 }
 
-func NewNagiosParser() (Parser, error) {
-	return &nagios.NagiosParser{}, nil
-}
-
 func NewInfluxParser() (Parser, error) {
 	handler := influx.NewMetricHandler()
 	return influx.NewParser(handler), nil