Add snmp_trap input plugin (#6629)

plugins/inputs/snmp_trap/snmp_trap_test.go

@@ -0,0 +1,222 @@
+package snmp_trap
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/soniah/gosnmp"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal"
+	"github.com/influxdata/telegraf/testutil"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoad(t *testing.T) {
+	s := &SnmpTrap{}
+	require.Nil(t, s.Init())
+
+	defer s.clear()
+	s.load(
+		".1.3.6.1.6.3.1.1.5.1",
+		mibEntry{
+			"SNMPv2-MIB",
+			"coldStart",
+		},
+	)
+
+	e, err := s.lookup(".1.3.6.1.6.3.1.1.5.1")
+	require.NoError(t, err)
+	require.Equal(t, "SNMPv2-MIB", e.mibName)
+	require.Equal(t, "coldStart", e.oidText)
+}
+
+func sendTrap(t *testing.T, port uint16) (sentTimestamp uint32) {
+	s := &gosnmp.GoSNMP{
+		Port:      port,
+		Community: "public",
+		Version:   gosnmp.Version2c,
+		Timeout:   time.Duration(2) * time.Second,
+		Retries:   3,
+		MaxOids:   gosnmp.MaxOids,
+		Target:    "127.0.0.1",
+	}
+
+	err := s.Connect()
+	if err != nil {
+		t.Errorf("Connect() err: %v", err)
+	}
+	defer s.Conn.Close()
+
+	// If the first pdu isn't type TimeTicks, gosnmp.SendTrap() will
+	// prepend one with time.Now().  The time value is part of the
+	// plugin output so we need to keep track of it and verify it
+	// later.
+	now := uint32(time.Now().Unix())
+	timePdu := gosnmp.SnmpPDU{
+		Name:  ".1.3.6.1.2.1.1.3.0",
+		Type:  gosnmp.TimeTicks,
+		Value: now,
+	}
+
+	pdu := gosnmp.SnmpPDU{
+		Name:  ".1.3.6.1.6.3.1.1.4.1.0", // SNMPv2-MIB::snmpTrapOID.0
+		Type:  gosnmp.ObjectIdentifier,
+		Value: ".1.3.6.1.6.3.1.1.5.1", // coldStart
+	}
+
+	trap := gosnmp.SnmpTrap{
+		Variables: []gosnmp.SnmpPDU{
+			timePdu,
+			pdu,
+		},
+	}
+
+	_, err = s.SendTrap(trap)
+	if err != nil {
+		t.Errorf("SendTrap() err: %v", err)
+	}
+
+	return now
+}
+
+func TestReceiveTrap(t *testing.T) {
+	// We would prefer to specify port 0 and let the network stack
+	// choose an unused port for us but TrapListener doesn't have a
+	// way to return the autoselected port.  Instead, we'll use an
+	// unusual port and hope it's unused.
+	const port = 12399
+	var fakeTime = time.Now()
+
+	// hook into the trap handler so the test knows when the trap has
+	// been received
+	received := make(chan int)
+	wrap := func(f handler) handler {
+		return func(p *gosnmp.SnmpPacket, a *net.UDPAddr) {
+			f(p, a)
+			received <- 0
+		}
+	}
+
+	// set up the service input plugin
+	s := &SnmpTrap{
+		ServiceAddress:     "udp://:" + strconv.Itoa(port),
+		makeHandlerWrapper: wrap,
+		timeFunc: func() time.Time {
+			return fakeTime
+		},
+		Log: testutil.Logger{},
+	}
+	require.Nil(t, s.Init())
+	var acc testutil.Accumulator
+	require.Nil(t, s.Start(&acc))
+	defer s.Stop()
+
+	// Preload the cache with the oids we'll use in this test so
+	// snmptranslate and mibs don't need to be installed.
+	defer s.clear()
+	s.load(".1.3.6.1.6.3.1.1.4.1.0",
+		mibEntry{
+			"SNMPv2-MIB",
+			"snmpTrapOID.0",
+		})
+	s.load(".1.3.6.1.6.3.1.1.5.1",
+		mibEntry{
+			"SNMPv2-MIB",
+			"coldStart",
+		})
+	s.load(".1.3.6.1.2.1.1.3.0",
+		mibEntry{
+			"UNUSED_MIB_NAME",
+			"sysUpTimeInstance",
+		})
+
+	// send the trap
+	sentTimestamp := sendTrap(t, port)
+
+	// wait for trap to be received
+	select {
+	case <-received:
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for trap to be received")
+	}
+
+	// verify plugin output
+	expected := []telegraf.Metric{
+		testutil.MustMetric(
+			"snmp_trap", // name
+			map[string]string{ // tags
+				"oid":     ".1.3.6.1.6.3.1.1.5.1",
+				"name":    "coldStart",
+				"mib":     "SNMPv2-MIB",
+				"version": "2c",
+				"source":  "127.0.0.1",
+			},
+			map[string]interface{}{ // fields
+				"sysUpTimeInstance": sentTimestamp,
+			},
+			fakeTime,
+		),
+	}
+
+	testutil.RequireMetricsEqual(t,
+		expected, acc.GetTelegrafMetrics(),
+		testutil.SortMetrics())
+
+}
+
+func fakeExecCmd(_ internal.Duration, _ string, _ ...string) ([]byte, error) {
+	return nil, fmt.Errorf("intentional failure")
+}
+
+func TestMissingOid(t *testing.T) {
+	// should fail even if snmptranslate is installed
+	const port = 12399
+	var fakeTime = time.Now()
+
+	received := make(chan int)
+	wrap := func(f handler) handler {
+		return func(p *gosnmp.SnmpPacket, a *net.UDPAddr) {
+			f(p, a)
+			received <- 0
+		}
+	}
+
+	s := &SnmpTrap{
+		ServiceAddress:     "udp://:" + strconv.Itoa(port),
+		makeHandlerWrapper: wrap,
+		timeFunc: func() time.Time {
+			return fakeTime
+		},
+		Log: testutil.Logger{},
+	}
+	require.Nil(t, s.Init())
+	var acc testutil.Accumulator
+	require.Nil(t, s.Start(&acc))
+	defer s.Stop()
+
+	// make sure the cache is empty
+	s.clear()
+
+	// don't call the real snmptranslate
+	s.execCmd = fakeExecCmd
+
+	_ = sendTrap(t, port)
+
+	select {
+	case <-received:
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for trap to be received")
+	}
+
+	// oid lookup should fail so we shouldn't get a metric
+	expected := []telegraf.Metric{}
+
+	testutil.RequireMetricsEqual(t,
+		expected, acc.GetTelegrafMetrics(),
+		testutil.SortMetrics())
+}