Add Wavefront parser (#4402)

docs/DATA_FORMATS_INPUT.md

@@ -10,6 +10,7 @@ Telegraf is able to parse the following input data formats into metrics:
 1. [Collectd](#collectd)
 1. [Dropwizard](#dropwizard)
 1. [Grok](#grok)
+1. [Wavefront](https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md#wavefront)
 
 Telegraf metrics, like InfluxDB
 [points](https://docs.influxdata.com/influxdb/v0.10/write_protocols/line/),
@@ -881,3 +882,29 @@ the file output will only print once per `flush_interval`.
 - Continue one token at a time until the entire line is successfully parsed.
 
 
+```
+
+# Wavefront:
+
+Wavefront Data Format is metrics are parsed directly into Telegraf metrics.
+For more information about the Wavefront Data Format see
+[here](https://docs.wavefront.com/wavefront_data_format.html).
+
+There are no additional configuration options for Wavefront Data Format line-protocol.
+
+#### Wavefront Configuration:
+
+```toml
+[[inputs.exec]]
+  ## Commands array
+  commands = ["/tmp/test.sh", "/usr/bin/mycollector --foo=bar"]
+
+  ## measurement name suffix (for separating different commands)
+  name_suffix = "_mycollector"
+
+  ## Data format to consume.
+  ## Each data format has its own unique set of configuration options, read
+  ## more about them here:
+  ## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md
+  data_format = "wavefront"
+```

plugins/outputs/wavefront/wavefront.go

@@ -189,8 +189,12 @@ func buildTags(mTags map[string]string, w *Wavefront) (string, map[string]string
 	}
 
 	var source string
-	sourceTagFound := false
 
+	if s, ok := mTags["source"]; ok {
+		source = s
+		delete(mTags, "source")
+	} else {
+		sourceTagFound := false
 		for _, s := range w.SourceOverride {
 			for k, v := range mTags {
 				if k == s {
@@ -209,6 +213,8 @@ func buildTags(mTags map[string]string, w *Wavefront) (string, map[string]string
 		if !sourceTagFound {
 			source = mTags["host"]
 		}
+	}
+
 	delete(mTags, "host")
 
 	return tagValueReplacer.Replace(source), mTags

plugins/parsers/registry.go

@@ -13,6 +13,7 @@ import (
 	"github.com/influxdata/telegraf/plugins/parsers/json"
 	"github.com/influxdata/telegraf/plugins/parsers/nagios"
 	"github.com/influxdata/telegraf/plugins/parsers/value"
+	"github.com/influxdata/telegraf/plugins/parsers/wavefront"
 )
 
 // ParserInput is an interface for input plugins that are able to parse
@@ -131,6 +132,8 @@ func NewParser(config *Config) (Parser, error) {
 			config.DefaultTags,
 			config.Separator,
 			config.Templates)
+	case "wavefront":
+		parser, err = NewWavefrontParser(config.DefaultTags)
 	case "grok":
 		parser, err = newGrokParser(
 			config.MetricName,
@@ -238,3 +241,7 @@ func NewDropwizardParser(
 	}
 	return parser, err
 }
+
+func NewWavefrontParser(defaultTags map[string]string) (Parser, error) {
+	return wavefront.NewWavefrontParser(defaultTags), nil
+}

plugins/parsers/wavefront/element.go

@@ -0,0 +1,238 @@
+package wavefront
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"time"
+)
+
+var (
+	ErrEOF              = errors.New("EOF")
+	ErrInvalidTimestamp = errors.New("Invalid timestamp")
+)
+
+// Interface for parsing line elements.
+type ElementParser interface {
+	parse(p *PointParser, pt *Point) error
+}
+
+type NameParser struct{}
+type ValueParser struct{}
+type TimestampParser struct {
+	optional bool
+}
+type WhiteSpaceParser struct {
+	nextOptional bool
+}
+type TagParser struct{}
+type LoopedParser struct {
+	wrappedParser ElementParser
+	wsPaser       *WhiteSpaceParser
+}
+type LiteralParser struct {
+	literal string
+}
+
+func (ep *NameParser) parse(p *PointParser, pt *Point) error {
+	//Valid characters are: a-z, A-Z, 0-9, hyphen ("-"), underscore ("_"), dot (".").
+	// Forward slash ("/") and comma (",") are allowed if metricName is enclosed in double quotes.
+	name, err := parseLiteral(p)
+	if err != nil {
+		return err
+	}
+	pt.Name = name
+	return nil
+}
+
+func (ep *ValueParser) parse(p *PointParser, pt *Point) error {
+	tok, lit := p.scan()
+	if tok == EOF {
+		return fmt.Errorf("found %q, expected number", lit)
+	}
+
+	p.writeBuf.Reset()
+	if tok == MINUS_SIGN {
+		p.writeBuf.WriteString(lit)
+		tok, lit = p.scan()
+	}
+
+	for tok != EOF && (tok == LETTER || tok == NUMBER || tok == DOT) {
+		p.writeBuf.WriteString(lit)
+		tok, lit = p.scan()
+	}
+	p.unscan()
+
+	pt.Value = p.writeBuf.String()
+	_, err := strconv.ParseFloat(pt.Value, 64)
+	if err != nil {
+		return fmt.Errorf("invalid metric value %s", pt.Value)
+	}
+	return nil
+}
+
+func (ep *TimestampParser) parse(p *PointParser, pt *Point) error {
+	tok, lit := p.scan()
+	if tok == EOF {
+		if ep.optional {
+			p.unscanTokens(2)
+			return setTimestamp(pt, 0, 1)
+		}
+		return fmt.Errorf("found %q, expected number", lit)
+	}
+
+	if tok != NUMBER {
+		if ep.optional {
+			p.unscanTokens(2)
+			return setTimestamp(pt, 0, 1)
+		}
+		return ErrInvalidTimestamp
+	}
+
+	p.writeBuf.Reset()
+	for tok != EOF && tok == NUMBER {
+		p.writeBuf.WriteString(lit)
+		tok, lit = p.scan()
+	}
+	p.unscan()
+
+	tsStr := p.writeBuf.String()
+	ts, err := strconv.ParseInt(tsStr, 10, 64)
+	if err != nil {
+		return err
+	}
+	return setTimestamp(pt, ts, len(tsStr))
+}
+
+func setTimestamp(pt *Point, ts int64, numDigits int) error {
+
+	if numDigits == 19 {
+		// nanoseconds
+		ts = ts / 1e9
+	} else if numDigits == 16 {
+		// microseconds
+		ts = ts / 1e6
+	} else if numDigits == 13 {
+		// milliseconds
+		ts = ts / 1e3
+	} else if numDigits != 10 {
+		// must be in seconds, return error if not 0
+		if ts == 0 {
+			ts = getCurrentTime()
+		} else {
+			return ErrInvalidTimestamp
+		}
+	}
+	pt.Timestamp = ts
+	return nil
+}
+
+func (ep *LoopedParser) parse(p *PointParser, pt *Point) error {
+	for {
+		err := ep.wrappedParser.parse(p, pt)
+		if err != nil {
+			return err
+		}
+		err = ep.wsPaser.parse(p, pt)
+		if err == ErrEOF {
+			break
+		}
+	}
+	return nil
+}
+
+func (ep *TagParser) parse(p *PointParser, pt *Point) error {
+	k, err := parseLiteral(p)
+	if err != nil {
+		if k == "" {
+			return nil
+		}
+		return err
+	}
+
+	next, lit := p.scan()
+	if next != EQUALS {
+		return fmt.Errorf("found %q, expected equals", lit)
+	}
+
+	v, err := parseLiteral(p)
+	if err != nil {
+		return err
+	}
+	if len(pt.Tags) == 0 {
+		pt.Tags = make(map[string]string)
+	}
+	pt.Tags[k] = v
+	return nil
+}
+
+func (ep *WhiteSpaceParser) parse(p *PointParser, pt *Point) error {
+	tok := WS
+	for tok != EOF && tok == WS {
+		tok, _ = p.scan()
+	}
+
+	if tok == EOF {
+		if !ep.nextOptional {
+			return ErrEOF
+		}
+		return nil
+	}
+	p.unscan()
+	return nil
+}
+
+func (ep *LiteralParser) parse(p *PointParser, pt *Point) error {
+	l, err := parseLiteral(p)
+	if err != nil {
+		return err
+	}
+
+	if l != ep.literal {
+		return fmt.Errorf("found %s, expected %s", l, ep.literal)
+	}
+	return nil
+}
+
+func parseQuotedLiteral(p *PointParser) (string, error) {
+	p.writeBuf.Reset()
+
+	escaped := false
+	tok, lit := p.scan()
+	for tok != EOF && (tok != QUOTES || (tok == QUOTES && escaped)) {
+		// let everything through
+		escaped = tok == BACKSLASH
+		p.writeBuf.WriteString(lit)
+		tok, lit = p.scan()
+	}
+	if tok == EOF {
+		return "", fmt.Errorf("found %q, expected quotes", lit)
+	}
+	return p.writeBuf.String(), nil
+}
+
+func parseLiteral(p *PointParser) (string, error) {
+	tok, lit := p.scan()
+	if tok == EOF {
+		return "", fmt.Errorf("found %q, expected literal", lit)
+	}
+
+	if tok == QUOTES {
+		return parseQuotedLiteral(p)
+	}
+
+	p.writeBuf.Reset()
+	for tok != EOF && tok > literal_beg && tok < literal_end {
+		p.writeBuf.WriteString(lit)
+		tok, lit = p.scan()
+	}
+	if tok == QUOTES {
+		return "", errors.New("found quote inside unquoted literal")
+	}
+	p.unscan()
+	return p.writeBuf.String(), nil
+}
+
+func getCurrentTime() int64 {
+	return time.Now().UnixNano() / 1e9
+}

plugins/parsers/wavefront/parser.go

@@ -0,0 +1,203 @@
+package wavefront
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"log"
+	"strconv"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/metric"
+)
+
+const MAX_BUFFER_SIZE = 2
+
+type Point struct {
+	Name      string
+	Value     string
+	Timestamp int64
+	Source    string
+	Tags      map[string]string
+}
+
+// Parser represents a parser.
+type PointParser struct {
+	s   *PointScanner
+	buf struct {
+		tok []Token  // last read n tokens
+		lit []string // last read n literals
+		n   int      // unscanned buffer size (max=2)
+	}
+	scanBuf     bytes.Buffer // buffer reused for scanning tokens
+	writeBuf    bytes.Buffer // buffer reused for parsing elements
+	Elements    []ElementParser
+	defaultTags map[string]string
+}
+
+// Returns a slice of ElementParser's for the Graphite format
+func NewWavefrontElements() []ElementParser {
+	var elements []ElementParser
+	wsParser := WhiteSpaceParser{}
+	wsParserNextOpt := WhiteSpaceParser{nextOptional: true}
+	repeatParser := LoopedParser{wrappedParser: &TagParser{}, wsPaser: &wsParser}
+	elements = append(elements, &NameParser{}, &wsParser, &ValueParser{}, &wsParserNextOpt,
+		&TimestampParser{optional: true}, &wsParserNextOpt, &repeatParser)
+	return elements
+}
+
+func NewWavefrontParser(defaultTags map[string]string) *PointParser {
+	elements := NewWavefrontElements()
+	return &PointParser{Elements: elements, defaultTags: defaultTags}
+}
+
+func (p *PointParser) Parse(buf []byte) ([]telegraf.Metric, error) {
+
+	// parse even if the buffer begins with a newline
+	buf = bytes.TrimPrefix(buf, []byte("\n"))
+	// add newline to end if not exists:
+	if len(buf) > 0 && !bytes.HasSuffix(buf, []byte("\n")) {
+		buf = append(buf, []byte("\n")...)
+	}
+
+	points := make([]Point, 0)
+
+	buffer := bytes.NewBuffer(buf)
+	reader := bufio.NewReader(buffer)
+	for {
+		// Read up to the next newline.
+		buf, err := reader.ReadBytes('\n')
+		if err == io.EOF {
+			break
+		}
+
+		p.reset(buf)
+		point := Point{}
+		for _, element := range p.Elements {
+			err := element.parse(p, &point)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		points = append(points, point)
+	}
+
+	metrics, err := p.convertPointToTelegrafMetric(points)
+	if err != nil {
+		return nil, err
+	}
+	return metrics, nil
+}
+
+func (p *PointParser) ParseLine(line string) (telegraf.Metric, error) {
+	buf := []byte(line)
+	metrics, err := p.Parse(buf)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(metrics) > 0 {
+		return metrics[0], nil
+	}
+
+	return nil, nil
+}
+
+func (p *PointParser) SetDefaultTags(tags map[string]string) {
+	p.defaultTags = tags
+}
+
+func (p *PointParser) convertPointToTelegrafMetric(points []Point) ([]telegraf.Metric, error) {
+
+	metrics := make([]telegraf.Metric, 0)
+
+	for _, point := range points {
+		tags := make(map[string]string)
+		for k, v := range point.Tags {
+			tags[k] = v
+		}
+		// apply default tags after parsed tags
+		for k, v := range p.defaultTags {
+			tags[k] = v
+		}
+
+		// single field for value
+		fields := make(map[string]interface{})
+		v, err := strconv.ParseFloat(point.Value, 64)
+		if err != nil {
+			return nil, err
+		}
+		fields["value"] = v
+
+		m, err := metric.New(point.Name, tags, fields, time.Unix(point.Timestamp, 0))
+		if err != nil {
+			return nil, err
+		}
+
+		metrics = append(metrics, m)
+	}
+
+	return metrics, nil
+}
+
+// scan returns the next token from the underlying scanner.
+// If a token has been unscanned then read that from the internal buffer instead.
+func (p *PointParser) scan() (Token, string) {
+	// If we have a token on the buffer, then return it.
+	if p.buf.n != 0 {
+		idx := p.buf.n % MAX_BUFFER_SIZE
+		tok, lit := p.buf.tok[idx], p.buf.lit[idx]
+		p.buf.n -= 1
+		return tok, lit
+	}
+
+	// Otherwise read the next token from the scanner.
+	tok, lit := p.s.Scan()
+
+	// Save it to the buffer in case we unscan later.
+	p.buffer(tok, lit)
+
+	return tok, lit
+}
+
+func (p *PointParser) buffer(tok Token, lit string) {
+	// create the buffer if it is empty
+	if len(p.buf.tok) == 0 {
+		p.buf.tok = make([]Token, MAX_BUFFER_SIZE)
+		p.buf.lit = make([]string, MAX_BUFFER_SIZE)
+	}
+
+	// for now assume a simple circular buffer of length two
+	p.buf.tok[0], p.buf.lit[0] = p.buf.tok[1], p.buf.lit[1]
+	p.buf.tok[1], p.buf.lit[1] = tok, lit
+}
+
+// unscan pushes the previously read token back onto the buffer.
+func (p *PointParser) unscan() {
+	p.unscanTokens(1)
+}
+
+func (p *PointParser) unscanTokens(n int) {
+	if n > MAX_BUFFER_SIZE {
+		// just log for now
+		log.Printf("cannot unscan more than %d tokens", MAX_BUFFER_SIZE)
+	}
+	p.buf.n += n
+}
+
+func (p *PointParser) reset(buf []byte) {
+
+	// reset the scan buffer and write new byte
+	p.scanBuf.Reset()
+	p.scanBuf.Write(buf)
+
+	if p.s == nil {
+		p.s = NewScanner(&p.scanBuf)
+	} else {
+		// reset p.s.r passing in the buffer as the reader
+		p.s.r.Reset(&p.scanBuf)
+	}
+	p.buf.n = 0
+}

plugins/parsers/wavefront/parser_test.go

@@ -0,0 +1,204 @@
+package wavefront
+
+import (
+	"testing"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/metric"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParse(t *testing.T) {
+	parser := NewWavefrontParser(nil)
+
+	parsedMetrics, err := parser.Parse([]byte("test.metric 1"))
+	assert.NoError(t, err)
+	testMetric, err := metric.New("test.metric", map[string]string{}, map[string]interface{}{"value": 1.}, time.Unix(0, 0))
+	assert.NoError(t, err)
+	assert.Equal(t, parsedMetrics[0].Name(), testMetric.Name())
+	assert.Equal(t, parsedMetrics[0].Fields(), testMetric.Fields())
+
+	parsedMetrics, err = parser.Parse([]byte("test.metric 1 1530939936"))
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+	parsedMetrics, err = parser.Parse([]byte("test.metric 1 1530939936 source=mysource"))
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+	parsedMetrics, err = parser.Parse([]byte("\"test.metric\" 1.1234 1530939936 source=\"mysource\""))
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+	parsedMetrics, err = parser.Parse([]byte("\"test.metric\" 1.1234 1530939936 \"source\"=\"mysource\" tag2=value2"))
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource", "tag2": "value2"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+	parsedMetrics, err = parser.Parse([]byte("test.metric		 1.1234      1530939936 	source=\"mysource\"    tag2=value2     "))
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource", "tag2": "value2"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+}
+
+func TestParseLine(t *testing.T) {
+	parser := NewWavefrontParser(nil)
+
+	parsedMetric, err := parser.ParseLine("test.metric 1")
+	assert.NoError(t, err)
+	testMetric, err := metric.New("test.metric", map[string]string{}, map[string]interface{}{"value": 1.}, time.Unix(0, 0))
+	assert.NoError(t, err)
+	assert.Equal(t, parsedMetric.Name(), testMetric.Name())
+	assert.Equal(t, parsedMetric.Fields(), testMetric.Fields())
+
+	parsedMetric, err = parser.ParseLine("test.metric 1 1530939936")
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetric, testMetric)
+
+	parsedMetric, err = parser.ParseLine("test.metric 1 1530939936 source=mysource")
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetric, testMetric)
+
+	parsedMetric, err = parser.ParseLine("\"test.metric\" 1.1234 1530939936 source=\"mysource\"")
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetric, testMetric)
+
+	parsedMetric, err = parser.ParseLine("\"test.metric\" 1.1234 1530939936 \"source\"=\"mysource\" tag2=value2")
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource", "tag2": "value2"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetric, testMetric)
+
+	parsedMetric, err = parser.ParseLine("test.metric		 1.1234      1530939936 	source=\"mysource\"    tag2=value2     ")
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"source": "mysource", "tag2": "value2"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetric, testMetric)
+}
+
+func TestParseMultiple(t *testing.T) {
+	parser := NewWavefrontParser(nil)
+
+	parsedMetrics, err := parser.Parse([]byte("test.metric 1\ntest.metric2 2 1530939936"))
+	assert.NoError(t, err)
+	testMetric1, err := metric.New("test.metric", map[string]string{}, map[string]interface{}{"value": 1.}, time.Unix(0, 0))
+	assert.NoError(t, err)
+	testMetric2, err := metric.New("test.metric2", map[string]string{}, map[string]interface{}{"value": 2.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetrics := []telegraf.Metric{testMetric1, testMetric2}
+	assert.Equal(t, parsedMetrics[0].Name(), testMetrics[0].Name())
+	assert.Equal(t, parsedMetrics[0].Fields(), testMetrics[0].Fields())
+	assert.EqualValues(t, parsedMetrics[1], testMetrics[1])
+
+	parsedMetrics, err = parser.Parse([]byte("test.metric 1 1530939936 source=mysource\n\"test.metric\" 1.1234 1530939936 source=\"mysource\""))
+	assert.NoError(t, err)
+	testMetric1, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetric2, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetrics = []telegraf.Metric{testMetric1, testMetric2}
+	assert.EqualValues(t, parsedMetrics, testMetrics)
+
+	parsedMetrics, err = parser.Parse([]byte("\"test.metric\" 1.1234 1530939936 \"source\"=\"mysource\" tag2=value2\ntest.metric		 1.1234      1530939936 	source=\"mysource\"    tag2=value2     "))
+	assert.NoError(t, err)
+	testMetric1, err = metric.New("test.metric", map[string]string{"source": "mysource", "tag2": "value2"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetric2, err = metric.New("test.metric", map[string]string{"source": "mysource", "tag2": "value2"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetrics = []telegraf.Metric{testMetric1, testMetric2}
+	assert.EqualValues(t, parsedMetrics, testMetrics)
+
+	parsedMetrics, err = parser.Parse([]byte("test.metric 1 1530939936 source=mysource\n\"test.metric\" 1.1234 1530939936 source=\"mysource\"\ntest.metric3 333 1530939936 tagit=valueit"))
+	assert.NoError(t, err)
+	testMetric1, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetric2, err = metric.New("test.metric", map[string]string{"source": "mysource"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetric3, err := metric.New("test.metric3", map[string]string{"tagit": "valueit"}, map[string]interface{}{"value": 333.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	testMetrics = []telegraf.Metric{testMetric1, testMetric2, testMetric3}
+	assert.EqualValues(t, parsedMetrics, testMetrics)
+
+}
+
+func TestParseSpecial(t *testing.T) {
+	parser := NewWavefrontParser(nil)
+
+	parsedMetric, err := parser.ParseLine("\"test.metric\" 1 1530939936")
+	assert.NoError(t, err)
+	testMetric, err := metric.New("test.metric", map[string]string{}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetric, testMetric)
+
+	parsedMetric, err = parser.ParseLine("test.metric 1 1530939936 tag1=\"val\\\"ue1\"")
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"tag1": "val\\\"ue1"}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetric, testMetric)
+
+}
+
+func TestParseInvalid(t *testing.T) {
+	parser := NewWavefrontParser(nil)
+
+	_, err := parser.Parse([]byte("test.metric"))
+	assert.Error(t, err)
+
+	_, err = parser.Parse([]byte("test.metric string"))
+	assert.Error(t, err)
+
+	_, err = parser.Parse([]byte("test.metric 1 string"))
+	assert.Error(t, err)
+
+	_, err = parser.Parse([]byte("test.metric 1 1530939936 tag_no_pair"))
+	assert.Error(t, err)
+
+	_, err = parser.Parse([]byte("test.metric 1 1530939936 tag_broken_value=\""))
+	assert.Error(t, err)
+
+	_, err = parser.Parse([]byte("\"test.metric 1 1530939936"))
+	assert.Error(t, err)
+
+	_, err = parser.Parse([]byte("test.metric 1 1530939936 tag1=val\\\"ue1"))
+	assert.Error(t, err)
+
+}
+
+func TestParseDefaultTags(t *testing.T) {
+	parser := NewWavefrontParser(map[string]string{"myDefault": "value1", "another": "test2"})
+
+	parsedMetrics, err := parser.Parse([]byte("test.metric 1 1530939936"))
+	assert.NoError(t, err)
+	testMetric, err := metric.New("test.metric", map[string]string{"myDefault": "value1", "another": "test2"}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+	parsedMetrics, err = parser.Parse([]byte("test.metric 1 1530939936 source=mysource"))
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"myDefault": "value1", "another": "test2", "source": "mysource"}, map[string]interface{}{"value": 1.}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+	parsedMetrics, err = parser.Parse([]byte("\"test.metric\" 1.1234 1530939936 another=\"test3\""))
+	assert.NoError(t, err)
+	testMetric, err = metric.New("test.metric", map[string]string{"myDefault": "value1", "another": "test2"}, map[string]interface{}{"value": 1.1234}, time.Unix(1530939936, 0))
+	assert.NoError(t, err)
+	assert.EqualValues(t, parsedMetrics[0], testMetric)
+
+}

plugins/parsers/wavefront/scanner.go

@@ -0,0 +1,69 @@
+package wavefront
+
+import (
+	"bufio"
+	"io"
+)
+
+// Lexical Point Scanner
+type PointScanner struct {
+	r *bufio.Reader
+}
+
+func NewScanner(r io.Reader) *PointScanner {
+	return &PointScanner{r: bufio.NewReader(r)}
+}
+
+// read reads the next rune from the buffered reader.
+// Returns rune(0) if an error occurs (or io.EOF is returned).
+func (s *PointScanner) read() rune {
+	ch, _, err := s.r.ReadRune()
+	if err != nil {
+		return eof
+	}
+	return ch
+}
+
+// unread places the previously read rune back on the reader.
+func (s *PointScanner) unread() {
+	_ = s.r.UnreadRune()
+}
+
+// Scan returns the next token and literal value.
+func (s *PointScanner) Scan() (Token, string) {
+
+	// Read the next rune
+	ch := s.read()
+	if isWhitespace(ch) {
+		return WS, string(ch)
+	} else if isLetter(ch) {
+		return LETTER, string(ch)
+	} else if isNumber(ch) {
+		return NUMBER, string(ch)
+	}
+
+	// Otherwise read the individual character.
+	switch ch {
+	case eof:
+		return EOF, ""
+	case '\n':
+		return NEWLINE, string(ch)
+	case '.':
+		return DOT, string(ch)
+	case '-':
+		return MINUS_SIGN, string(ch)
+	case '_':
+		return UNDERSCORE, string(ch)
+	case '/':
+		return SLASH, string(ch)
+	case '\\':
+		return BACKSLASH, string(ch)
+	case ',':
+		return COMMA, string(ch)
+	case '"':
+		return QUOTES, string(ch)
+	case '=':
+		return EQUALS, string(ch)
+	}
+	return ILLEGAL, string(ch)
+}

plugins/parsers/wavefront/token.go

@@ -0,0 +1,41 @@
+package wavefront
+
+type Token int
+
+const (
+	// Special tokens
+	ILLEGAL Token = iota
+	EOF
+	WS
+
+	// Literals
+	literal_beg
+	LETTER // metric name, source/point tags
+	NUMBER
+	MINUS_SIGN
+	UNDERSCORE
+	DOT
+	SLASH
+	BACKSLASH
+	COMMA
+	literal_end
+
+	// Misc characters
+	QUOTES
+	EQUALS
+	NEWLINE
+)
+
+func isWhitespace(ch rune) bool {
+	return ch == ' ' || ch == '\t' || ch == '\n'
+}
+
+func isLetter(ch rune) bool {
+	return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')
+}
+
+func isNumber(ch rune) bool {
+	return ch >= '0' && ch <= '9'
+}
+
+var eof = rune(0)