Add syslog output plugin (#5802)

internal/syslog/framing.go

@@ -0,0 +1,64 @@
+package syslog
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Framing represents the framing technique we expect the messages to come.
+type Framing int
+
+const (
+	// OctetCounting indicates the transparent framing technique for syslog transport.
+	OctetCounting Framing = iota
+	// NonTransparent indicates the non-transparent framing technique for syslog transport.
+	NonTransparent
+)
+
+func (f Framing) String() string {
+	switch f {
+	case OctetCounting:
+		return "OCTET-COUNTING"
+	case NonTransparent:
+		return "NON-TRANSPARENT"
+	}
+	return ""
+}
+
+// UnmarshalTOML implements ability to unmarshal framing from TOML files.
+func (f *Framing) UnmarshalTOML(data []byte) (err error) {
+	return f.UnmarshalText(data)
+}
+
+// UnmarshalText implements encoding.TextUnmarshaler
+func (f *Framing) UnmarshalText(data []byte) (err error) {
+	s := string(data)
+	switch strings.ToUpper(s) {
+	case `OCTET-COUNTING`:
+		fallthrough
+	case `"OCTET-COUNTING"`:
+		fallthrough
+	case `'OCTET-COUNTING'`:
+		*f = OctetCounting
+		return
+
+	case `NON-TRANSPARENT`:
+		fallthrough
+	case `"NON-TRANSPARENT"`:
+		fallthrough
+	case `'NON-TRANSPARENT'`:
+		*f = NonTransparent
+		return
+	}
+	*f = -1
+	return fmt.Errorf("unknown framing")
+}
+
+// MarshalText implements encoding.TextMarshaler
+func (f Framing) MarshalText() ([]byte, error) {
+	s := f.String()
+	if s != "" {
+		return []byte(s), nil
+	}
+	return nil, fmt.Errorf("unknown framing")
+}

internal/syslog/framing_test.go

@@ -0,0 +1,37 @@
+package syslog
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestFraming(t *testing.T) {
+	var f1 Framing
+	f1.UnmarshalTOML([]byte(`"non-transparent"`))
+	assert.Equal(t, NonTransparent, f1)
+
+	var f2 Framing
+	f2.UnmarshalTOML([]byte(`non-transparent`))
+	assert.Equal(t, NonTransparent, f2)
+
+	var f3 Framing
+	f3.UnmarshalTOML([]byte(`'non-transparent'`))
+	assert.Equal(t, NonTransparent, f3)
+
+	var f4 Framing
+	f4.UnmarshalTOML([]byte(`"octet-counting"`))
+	assert.Equal(t, OctetCounting, f4)
+
+	var f5 Framing
+	f5.UnmarshalTOML([]byte(`octet-counting`))
+	assert.Equal(t, OctetCounting, f5)
+
+	var f6 Framing
+	f6.UnmarshalTOML([]byte(`'octet-counting'`))
+	assert.Equal(t, OctetCounting, f6)
+
+	var f7 Framing
+	err := f7.UnmarshalTOML([]byte(`nope`))
+	assert.Equal(t, Framing(-1), f7)
+	assert.Error(t, err)
+}