Add ability to set measurement from matched text in grok parser (#4433)

plugins/inputs/file/README.md

@@ -14,7 +14,7 @@ use the [tail input plugin](/plugins/inputs/tail) instead.
   ## ** as a "super asterisk". ie:
   ##   /var/log/**.log     -> recursively find all .log files in /var/log
   ##   /var/log/*/*.log    -> find all .log files with a parent dir in /var/log
-  ##   /var/log/apache.log -> only tail the apache log file
+  ##   /var/log/apache.log -> only read the apache log file
   files = ["/var/log/apache/access.log"]
 
   ## Data format to consume.

plugins/inputs/file/dev/docker-compose.yml

@@ -6,7 +6,7 @@ services:
       volumes:
         - ./telegraf.conf:/telegraf.conf
         - ../../../../telegraf:/telegraf
-        - ./json_a.log:/var/log/test.log
+        - ./dev/json_a.log:/var/log/test.log
       entrypoint:
         - /telegraf
         - --config

plugins/inputs/file/dev/json_a.log

@@ -1,14 +0,0 @@
-{
-"parent": {
-	"child": 3.0,
-	"ignored_child": "hi"
-},
-"ignored_null": null,
-"integer": 4,
-"list": [3, 4],
-"ignored_parent": {
-	"another_ignored_null": null,
-	"ignored_string": "hello, world!"
-},
-"another_list": [4]
-}

plugins/inputs/file/file.go

@@ -11,9 +11,8 @@ import (
 )
 
 type File struct {
-	Files         []string `toml:"files"`
-	FromBeginning bool
-	parser        parsers.Parser
+	Files  []string `toml:"files"`
+	parser parsers.Parser
 
 	filenames []string
 }
@@ -24,7 +23,7 @@ const sampleConfig = `
   ## ** as a "super asterisk". ie:
   ##   /var/log/**.log     -> recursively find all .log files in /var/log
   ##   /var/log/*/*.log    -> find all .log files with a parent dir in /var/log
-  ##   /var/log/apache.log -> only tail the apache log file
+  ##   /var/log/apache.log -> only read the apache log file
   files = ["/var/log/apache/access.log"]
 
   ## The dataformat to be read from files
@@ -40,7 +39,7 @@ func (f *File) SampleConfig() string {
 }
 
 func (f *File) Description() string {
-	return "reload and gather from file[s] on telegraf's interval"
+	return "Reload and gather from file[s] on telegraf's interval."
 }
 
 func (f *File) Gather(acc telegraf.Accumulator) error {

plugins/inputs/file/file_test.go

@@ -14,26 +14,26 @@ import (
 func TestRefreshFilePaths(t *testing.T) {
 	wd, err := os.Getwd()
 	r := File{
-		Files: []string{filepath.Join(wd, "testfiles/**.log")},
+		Files: []string{filepath.Join(wd, "dev/testfiles/**.log")},
 	}
 
 	err = r.refreshFilePaths()
 	require.NoError(t, err)
-	assert.Equal(t, len(r.filenames), 2)
+	assert.Equal(t, 2, len(r.filenames))
 }
 func TestJSONParserCompile(t *testing.T) {
 	var acc testutil.Accumulator
 	wd, _ := os.Getwd()
 	r := File{
-		Files: []string{filepath.Join(wd, "testfiles/json_a.log")},
+		Files: []string{filepath.Join(wd, "dev/testfiles/json_a.log")},
 	}
 	parserConfig := parsers.Config{
 		DataFormat: "json",
 		TagKeys:    []string{"parent_ignored_child"},
 	}
 	nParser, err := parsers.NewParser(&parserConfig)
-	r.parser = nParser
 	assert.NoError(t, err)
+	r.parser = nParser
 
 	r.Gather(&acc)
 	assert.Equal(t, map[string]string{"parent_ignored_child": "hi"}, acc.Metrics[0].Tags)
@@ -44,7 +44,7 @@ func TestGrokParser(t *testing.T) {
 	wd, _ := os.Getwd()
 	var acc testutil.Accumulator
 	r := File{
-		Files: []string{filepath.Join(wd, "testfiles/grok_a.log")},
+		Files: []string{filepath.Join(wd, "dev/testfiles/grok_a.log")},
 	}
 
 	parserConfig := parsers.Config{
@@ -57,5 +57,5 @@ func TestGrokParser(t *testing.T) {
 	assert.NoError(t, err)
 
 	err = r.Gather(&acc)
-	assert.Equal(t, 2, len(acc.Metrics))
+	assert.Equal(t, len(acc.Metrics), 2)
 }

plugins/parsers/grok/parser.go

@@ -38,6 +38,7 @@ var timeLayouts = map[string]string{
 }
 
 const (
+	MEASUREMENT       = "measurement"
 	INT               = "int"
 	TAG               = "tag"
 	FLOAT             = "float"
@@ -217,7 +218,6 @@ func (p *Parser) ParseLine(line string) (telegraf.Metric, error) {
 		if k == "" || v == "" {
 			continue
 		}
-
 		// t is the modifier of the field
 		var t string
 		// check if pattern has some modifiers
@@ -239,6 +239,8 @@ func (p *Parser) ParseLine(line string) (telegraf.Metric, error) {
 		}
 
 		switch t {
+		case MEASUREMENT:
+			p.Measurement = v
 		case INT:
 			iv, err := strconv.ParseInt(v, 10, 64)
 			if err != nil {
@@ -350,7 +352,7 @@ func (p *Parser) ParseLine(line string) (telegraf.Metric, error) {
 	}
 
 	if len(fields) == 0 {
-		return nil, fmt.Errorf("logparser_grok: must have one or more fields")
+		return nil, fmt.Errorf("grok: must have one or more fields")
 	}
 
 	return metric.New(p.Measurement, tags, fields, p.tsModder.tsMod(timestamp))

plugins/parsers/grok/parser_test.go

@@ -1,6 +1,7 @@
 package grok
 
 import (
+	"log"
 	"testing"
 	"time"
 
@@ -959,3 +960,52 @@ func TestReplaceTimestampComma(t *testing.T) {
 	//Convert Nanosecond to milisecond for compare
 	require.Equal(t, 555, m.Time().Nanosecond()/1000000)
 }
+
+func TestDynamicMeasurementModifier(t *testing.T) {
+	p := &Parser{
+		Patterns:       []string{"%{TEST}"},
+		CustomPatterns: "TEST %{NUMBER:var1:tag} %{NUMBER:var2:float} %{WORD:test:measurement}",
+	}
+
+	require.NoError(t, p.Compile())
+	m, err := p.ParseLine("4 5 hello")
+	require.NoError(t, err)
+	require.Equal(t, m.Name(), "hello")
+}
+
+func TestStaticMeasurementModifier(t *testing.T) {
+	p := &Parser{
+		Patterns: []string{"%{WORD:hi:measurement} %{NUMBER:num:string}"},
+	}
+
+	require.NoError(t, p.Compile())
+	m, err := p.ParseLine("test_name 42")
+	log.Printf("%v", m)
+	require.NoError(t, err)
+	require.Equal(t, "test_name", m.Name())
+}
+
+// tests that the top level measurement name is used
+func TestTwoMeasurementModifier(t *testing.T) {
+	p := &Parser{
+		Patterns:       []string{"%{TEST:test_name:measurement}"},
+		CustomPatterns: "TEST %{NUMBER:var1:tag} %{NUMBER:var2:measurement} %{WORD:var3:measurement}",
+	}
+
+	require.NoError(t, p.Compile())
+	m, err := p.ParseLine("4 5 hello")
+	require.NoError(t, err)
+	require.Equal(t, m.Name(), "4 5 hello")
+}
+
+func TestMeasurementModifierNoName(t *testing.T) {
+	p := &Parser{
+		Patterns:       []string{"%{TEST}"},
+		CustomPatterns: "TEST %{NUMBER:var1:tag} %{NUMBER:var2:float} %{WORD:hi:measurement}",
+	}
+
+	require.NoError(t, p.Compile())
+	m, err := p.ParseLine("4 5 hello")
+	require.NoError(t, err)
+	require.Equal(t, m.Name(), "hello")
+}