Internally name all patterns for log parsing flexibility

closes #1436

This also fixes the bad behavior of waiting until runtime to return log
parsing pattern compile errors when a pattern was simply unfound.

closes #1418

Also protect against user error when the telegraf user does not have
permission to open the provided file. We will now error and exit in this
case, rather than silently waiting to get permission to open it.

CHANGELOG.md

@@ -63,6 +63,8 @@ should now look like:
 - [#1460](https://github.com/influxdata/telegraf/issues/1460): Remove PID from procstat plugin to fix cardinality issues.
 - [#1427](https://github.com/influxdata/telegraf/issues/1427): Cassandra input: version 2.x "column family" fix.
 - [#1463](https://github.com/influxdata/telegraf/issues/1463): Shared WaitGroup in Exec plugin
+- [#1436](https://github.com/influxdata/telegraf/issues/1436): logparser: honor modifiers in "pattern" config.
+- [#1418](https://github.com/influxdata/telegraf/issues/1418): logparser: error and exit on file permissions/missing errors.
 
 ## v1.0 beta 2 [2016-06-21]
 

plugins/inputs/logparser/grok/grok.go

@@ -53,7 +53,12 @@ var (
 )
 
 type Parser struct {
-	Patterns           []string
+	Patterns []string
+	// namedPatterns is a list of internally-assigned names to the patterns
+	// specified by the user in Patterns.
+	// They will look like:
+	//   GROK_INTERNAL_PATTERN_0, GROK_INTERNAL_PATTERN_1, etc.
+	namedPatterns      []string
 	CustomPatterns     string
 	CustomPatternFiles []string
 	Measurement        string
@@ -98,13 +103,24 @@ func (p *Parser) Compile() error {
 		return err
 	}
 
-	p.CustomPatterns = DEFAULT_PATTERNS + p.CustomPatterns
+	// Give Patterns fake names so that they can be treated as named
+	// "custom patterns"
+	p.namedPatterns = make([]string, len(p.Patterns))
+	for i, pattern := range p.Patterns {
+		name := fmt.Sprintf("GROK_INTERNAL_PATTERN_%d", i)
+		p.CustomPatterns += "\n" + name + " " + pattern + "\n"
+		p.namedPatterns[i] = "%{" + name + "}"
+	}
 
+	// Combine user-supplied CustomPatterns with DEFAULT_PATTERNS and parse
+	// them together as the same type of pattern.
+	p.CustomPatterns = DEFAULT_PATTERNS + p.CustomPatterns
 	if len(p.CustomPatterns) != 0 {
 		scanner := bufio.NewScanner(strings.NewReader(p.CustomPatterns))
 		p.addCustomPatterns(scanner)
 	}
 
+	// Parse any custom pattern files supplied.
 	for _, filename := range p.CustomPatternFiles {
 		file, err := os.Open(filename)
 		if err != nil {
@@ -127,7 +143,7 @@ func (p *Parser) ParseLine(line string) (telegraf.Metric, error) {
 	var values map[string]string
 	// the matching pattern string
 	var patternName string
-	for _, pattern := range p.Patterns {
+	for _, pattern := range p.namedPatterns {
 		if values, err = p.g.Parse(pattern, line); err != nil {
 			return nil, err
 		}

plugins/inputs/logparser/grok/grok_test.go

@@ -207,7 +207,7 @@ func TestBuiltinCombinedLogFormat(t *testing.T) {
 
 func TestCompileStringAndParse(t *testing.T) {
 	p := &Parser{
-		Patterns: []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
+		Patterns: []string{"%{TEST_LOG_A}"},
 		CustomPatterns: `
 			DURATION %{NUMBER}[nuµm]?s
 			RESPONSE_CODE %{NUMBER:response_code:tag}
@@ -230,6 +230,41 @@ func TestCompileStringAndParse(t *testing.T) {
 	assert.Equal(t, map[string]string{"response_code": "200"}, metricA.Tags())
 }
 
+func TestCompileErrorsOnInvalidPattern(t *testing.T) {
+	p := &Parser{
+		Patterns: []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
+		CustomPatterns: `
+			DURATION %{NUMBER}[nuµm]?s
+			RESPONSE_CODE %{NUMBER:response_code:tag}
+			RESPONSE_TIME %{DURATION:response_time:duration}
+			TEST_LOG_A %{NUMBER:myfloat:float} %{RESPONSE_CODE} %{IPORHOST:clientip} %{RESPONSE_TIME}
+		`,
+	}
+	assert.Error(t, p.Compile())
+
+	metricA, _ := p.ParseLine(`1.25 200 192.168.1.1 5.432µs`)
+	require.Nil(t, metricA)
+}
+
+func TestParsePatternsWithoutCustom(t *testing.T) {
+	p := &Parser{
+		Patterns: []string{"%{POSINT:ts:ts-epochnano} response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}"},
+	}
+	assert.NoError(t, p.Compile())
+
+	metricA, err := p.ParseLine(`1466004605359052000 response_time=20821 mymetric=10890.645`)
+	require.NotNil(t, metricA)
+	assert.NoError(t, err)
+	assert.Equal(t,
+		map[string]interface{}{
+			"response_time": int64(20821),
+			"metric":        float64(10890.645),
+		},
+		metricA.Fields())
+	assert.Equal(t, map[string]string{}, metricA.Tags())
+	assert.Equal(t, time.Unix(0, 1466004605359052000), metricA.Time())
+}
+
 func TestParseEpochNano(t *testing.T) {
 	p := &Parser{
 		Patterns: []string{"%{MYAPP}"},
@@ -413,7 +448,7 @@ func TestParseErrors(t *testing.T) {
 			TEST_LOG_A %{HTTPDATE:ts:ts-httpd} %{WORD:myword:int} %{}
 		`,
 	}
-	assert.NoError(t, p.Compile())
+	assert.Error(t, p.Compile())
 	_, err := p.ParseLine(`[04/Jun/2016:12:41:45 +0100] notnumber 200 192.168.1.1 5.432µs 101`)
 	assert.Error(t, err)
 

plugins/inputs/logparser/logparser.go

@@ -9,6 +9,7 @@ import (
 	"github.com/hpcloud/tail"
 
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal/errchan"
 	"github.com/influxdata/telegraf/internal/globpath"
 	"github.com/influxdata/telegraf/plugins/inputs"
 
@@ -110,11 +111,15 @@ func (l *LogParserPlugin) Start(acc telegraf.Accumulator) error {
 	}
 
 	// compile log parser patterns:
+	errChan := errchan.New(len(l.parsers))
 	for _, parser := range l.parsers {
 		if err := parser.Compile(); err != nil {
-			return err
+			errChan.C <- err
 		}
 	}
+	if err := errChan.Error(); err != nil {
+		return err
+	}
 
 	var seek tail.SeekInfo
 	if !l.FromBeginning {
@@ -125,35 +130,33 @@ func (l *LogParserPlugin) Start(acc telegraf.Accumulator) error {
 	l.wg.Add(1)
 	go l.parser()
 
-	var errS string
 	// Create a "tailer" for each file
 	for _, filepath := range l.Files {
 		g, err := globpath.Compile(filepath)
 		if err != nil {
 			log.Printf("ERROR Glob %s failed to compile, %s", filepath, err)
+			continue
 		}
-		for file, _ := range g.Match() {
+		files := g.Match()
+		errChan = errchan.New(len(files))
+		for file, _ := range files {
 			tailer, err := tail.TailFile(file,
 				tail.Config{
-					ReOpen:   true,
-					Follow:   true,
-					Location: &seek,
+					ReOpen:    true,
+					Follow:    true,
+					Location:  &seek,
+					MustExist: true,
 				})
-			if err != nil {
-				errS += err.Error() + " "
-				continue
-			}
+			errChan.C <- err
+
 			// create a goroutine for each "tailer"
 			l.wg.Add(1)
 			go l.receiver(tailer)
 			l.tailers = append(l.tailers, tailer)
 		}
 	}
 
-	if errS != "" {
-		return fmt.Errorf(errS)
-	}
-	return nil
+	return errChan.Error()
 }
 
 // receiver is launched as a goroutine to continuously watch a tailed logfile
@@ -201,8 +204,6 @@ func (l *LogParserPlugin) parser() {
 				if m != nil {
 					l.acc.AddFields(m.Name(), m.Fields(), m.Tags(), m.Time())
 				}
-			} else {
-				log.Printf("Malformed log line in [%s], Error: %s\n", line, err)
 			}
 		}
 	}

plugins/inputs/logparser/logparser_test.go

@@ -37,7 +37,7 @@ func TestGrokParseLogFilesNonExistPattern(t *testing.T) {
 	}
 
 	acc := testutil.Accumulator{}
-	assert.NoError(t, logparser.Start(&acc))
+	assert.Error(t, logparser.Start(&acc))
 
 	time.Sleep(time.Millisecond * 500)
 	logparser.Stop()
@@ -80,6 +80,8 @@ func TestGrokParseLogFiles(t *testing.T) {
 		map[string]string{})
 }
 
+// Test that test_a.log line gets parsed even though we don't have the correct
+// pattern available for test_b.log
 func TestGrokParseLogFilesOneBad(t *testing.T) {
 	thisdir := getCurrentDir()
 	p := &grok.Parser{
@@ -90,11 +92,12 @@ func TestGrokParseLogFilesOneBad(t *testing.T) {
 
 	logparser := &LogParserPlugin{
 		FromBeginning: true,
-		Files:         []string{thisdir + "grok/testdata/*.log"},
+		Files:         []string{thisdir + "grok/testdata/test_a.log"},
 		GrokParser:    p,
 	}
 
 	acc := testutil.Accumulator{}
+	acc.SetDebug(true)
 	assert.NoError(t, logparser.Start(&acc))
 
 	time.Sleep(time.Millisecond * 500)

plugins/inputs/tail/tail.go

@@ -86,9 +86,10 @@ func (t *Tail) Start(acc telegraf.Accumulator) error {
 		for file, _ := range g.Match() {
 			tailer, err := tail.TailFile(file,
 				tail.Config{
-					ReOpen:   true,
-					Follow:   true,
-					Location: &seek,
+					ReOpen:    true,
+					Follow:    true,
+					Location:  &seek,
+					MustExist: true,
 				})
 			if err != nil {
 				errS += err.Error() + " "