Syslogparser

This is a syslog parser for the Go programming language.

https://pkg.go.dev/github.com/jeromer/syslogparser

Installing

go get github.com/jeromer/syslogparser

Supported RFCs

• RFC 3164
• RFC 5424

Not all features described in RFCs above are supported but only the most part of it. For exaple SDIDs are not supported in RFC 5424 and STRUCTURED-DATA are parsed as a whole string.

This parser should solve 80% of use cases. If your use cases are in the 20% remaining ones I would recommend you to fully test what you want to achieve and provide a patch if you want.

Parsing an RFC 3164 syslog message

b := "<34>Oct 11 22:14:15 mymachine su: 'su root' failed for lonvick on /dev/pts/8"
buff := []byte(b)

p := rfc3164.NewParser(buff)
err := p.Parse()
if err != nil {
	panic(err)
}

for k, v := range p.Dump() {
	fmt.Println(k, ":", v)
}

You should see

timestamp : 2013-10-11 22:14:15 +0000 UTC
hostname  : mymachine
tag       : su
content   : 'su root' failed for lonvick on /dev/pts/8
priority  : 34
facility  : 4
severity  : 2

Parsing an RFC 5424 syslog message

b := `<165>1 2003-10-11T22:14:15.003Z mymachine.example.com evntslog - ID47 [exampleSDID@32473 iut="3" eventSource="Application" eventID="1011"] An application event log entry...`
buff := []byte(b)

p := rfc5424.NewParser(buff)
err := p.Parse()
if err != nil {
	panic(err)
}

for k, v := range p.Dump() {
	fmt.Println(k, ":", v)
}

You should see

version : 1
timestamp : 2003-10-11 22:14:15.003 +0000 UTC
app_name : evntslog
msg_id : ID47
message : An application event log entry...
priority : 165
facility : 20
severity : 5
hostname : mymachine.example.com
proc_id : -
structured_data : [exampleSDID@32473 iut="3" eventSource="Application" eventID="1011"]

Detecting message format

You can use the DetectRFC() function. Like this:

b := []byte(`<165>1 2003-10-11T22:14:15.003Z ...`)
rfc, err := syslogparser.DetectRFC(b)
if err != nil {
	panic(err)
}

switch rfc {
case RFC_UNKNOWN:
	fmt.Println("unknown")
case RFC_3164:
	fmt.Println("3164")
case RFC_5424:
	fmt.Println("5424")
}

Running tests

Run make test

Running benchmarks

Run make benchmark

go test -bench=. -benchmem
goos: linux
goarch: amd64
pkg: github.com/jeromer/syslogparser
BenchmarkDetectRFC-8   	81994480	        14.7 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	github.com/jeromer/syslogparser	2.145s

cd rfc3164 && go test -bench=. -benchmem
goos: linux
goarch: amd64
pkg: github.com/jeromer/syslogparser/rfc3164
BenchmarkParseTimestamp-8   	 2823901	       416 ns/op	      16 B/op	       1 allocs/op
BenchmarkParseHostname-8    	34796552	        35.4 ns/op	      16 B/op	       1 allocs/op
BenchmarkParseTag-8         	20954252	        59.3 ns/op	       8 B/op	       1 allocs/op
BenchmarkParseHeader-8      	 2276569	       596 ns/op	      80 B/op	       3 allocs/op
BenchmarkParsemessage-8     	 6751579	       192 ns/op	     104 B/op	       4 allocs/op
BenchmarkParseFull-8        	 1445076	       838 ns/op	     336 B/op	      10 allocs/op
PASS

ok  	github.com/jeromer/syslogparser/rfc3164	9.601s
cd rfc5424 && go test -bench=. -benchmem
goos: linux
goarch: amd64
pkg: github.com/jeromer/syslogparser/rfc5424
BenchmarkParseTimestamp-8   	  790478	      1488 ns/op	     432 B/op	      21 allocs/op
BenchmarkParseHeader-8      	 1000000	      1043 ns/op	     336 B/op	      18 allocs/op
BenchmarkParseFull-8        	  980828	      1306 ns/op	     672 B/op	      21 allocs/op
PASS
ok  	github.com/jeromer/syslogparser/rfc5424	4.356s