Make Logparser Plugin Check For New Files (#2141)

* Make Logparser Plugin Check For New Files

Check in the Gather metric to see if any new files matching the glob
have appeared. If so, start tailing them from the beginning.

* changelog update for #2141
This commit is contained in:
njwhite 2017-02-01 14:11:39 +00:00 committed by Cameron Sparr
parent 7549299e5e
commit 360b3a8b9f
3 changed files with 73 additions and 7 deletions

View File

@ -11,6 +11,7 @@ It is highly recommended that all users migrate to the new riemann output plugin
### Features
- [#2141](https://github.com/influxdata/telegraf/pull/2141): Logparser handles newly-created files.
- [#2137](https://github.com/influxdata/telegraf/pull/2137): Added userstats to mysql input plugin.
- [#2179](https://github.com/influxdata/telegraf/pull/2179): Added more InnoDB metric to MySQL plugin.
- [#2251](https://github.com/influxdata/telegraf/pull/2251): InfluxDB output: use own client for improved through-put and less allocations.

View File

@ -26,7 +26,7 @@ type LogParserPlugin struct {
Files []string
FromBeginning bool
tailers []*tail.Tail
tailers map[string]*tail.Tail
lines chan string
done chan struct{}
wg sync.WaitGroup
@ -46,7 +46,9 @@ const sampleConfig = `
## /var/log/*/*.log -> find all .log files with a parent dir in /var/log
## /var/log/apache.log -> only tail the apache log file
files = ["/var/log/apache/access.log"]
## Read file from beginning.
## Read files that currently exist from the beginning. Files that are created
## while telegraf is running (and that match the "files" globs) will always
## be read from the beginning.
from_beginning = false
## Parse logstash-style "grok" patterns:
@ -77,7 +79,11 @@ func (l *LogParserPlugin) Description() string {
}
func (l *LogParserPlugin) Gather(acc telegraf.Accumulator) error {
return nil
l.Lock()
defer l.Unlock()
// always start from the beginning of files that appear while we're running
return l.tailNewfiles(true)
}
func (l *LogParserPlugin) Start(acc telegraf.Accumulator) error {
@ -87,6 +93,7 @@ func (l *LogParserPlugin) Start(acc telegraf.Accumulator) error {
l.acc = acc
l.lines = make(chan string, 1000)
l.done = make(chan struct{})
l.tailers = make(map[string]*tail.Tail)
// Looks for fields which implement LogParser interface
l.parsers = []LogParser{}
@ -121,14 +128,22 @@ func (l *LogParserPlugin) Start(acc telegraf.Accumulator) error {
return err
}
l.wg.Add(1)
go l.parser()
return l.tailNewfiles(l.FromBeginning)
}
// check the globs against files on disk, and start tailing any new files.
// Assumes l's lock is held!
func (l *LogParserPlugin) tailNewfiles(fromBeginning bool) error {
var seek tail.SeekInfo
if !l.FromBeginning {
if !fromBeginning {
seek.Whence = 2
seek.Offset = 0
}
l.wg.Add(1)
go l.parser()
errChan := errchan.New(len(l.Files))
// Create a "tailer" for each file
for _, filepath := range l.Files {
@ -139,7 +154,13 @@ func (l *LogParserPlugin) Start(acc telegraf.Accumulator) error {
}
files := g.Match()
errChan = errchan.New(len(files))
for file, _ := range files {
if _, ok := l.tailers[file]; ok {
// we're already tailing this file
continue
}
tailer, err := tail.TailFile(file,
tail.Config{
ReOpen: true,
@ -152,7 +173,7 @@ func (l *LogParserPlugin) Start(acc telegraf.Accumulator) error {
// create a goroutine for each "tailer"
l.wg.Add(1)
go l.receiver(tailer)
l.tailers = append(l.tailers, tailer)
l.tailers[file] = tailer
}
}
@ -166,6 +187,7 @@ func (l *LogParserPlugin) receiver(tailer *tail.Tail) {
var line *tail.Line
for line = range tailer.Lines {
if line.Err != nil {
log.Printf("E! Error tailing file %s, Error: %s\n",
tailer.Filename, line.Err)

View File

@ -1,6 +1,8 @@
package logparser
import (
"io/ioutil"
"os"
"runtime"
"strings"
"testing"
@ -80,6 +82,47 @@ func TestGrokParseLogFiles(t *testing.T) {
map[string]string{})
}
func TestGrokParseLogFilesAppearLater(t *testing.T) {
emptydir, err := ioutil.TempDir("", "TestGrokParseLogFilesAppearLater")
defer os.RemoveAll(emptydir)
assert.NoError(t, err)
thisdir := getCurrentDir()
p := &grok.Parser{
Patterns: []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
CustomPatternFiles: []string{thisdir + "grok/testdata/test-patterns"},
}
logparser := &LogParserPlugin{
FromBeginning: true,
Files: []string{emptydir + "/*.log"},
GrokParser: p,
}
acc := testutil.Accumulator{}
assert.NoError(t, logparser.Start(&acc))
time.Sleep(time.Millisecond * 500)
assert.Equal(t, acc.NFields(), 0)
os.Symlink(
thisdir+"grok/testdata/test_a.log",
emptydir+"/test_a.log")
assert.NoError(t, logparser.Gather(&acc))
time.Sleep(time.Millisecond * 500)
logparser.Stop()
acc.AssertContainsTaggedFields(t, "logparser_grok",
map[string]interface{}{
"clientip": "192.168.1.1",
"myfloat": float64(1.25),
"response_time": int64(5432),
"myint": int64(101),
},
map[string]string{"response_code": "200"})
}
// 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) {