Add support for multiple line text and perfdata to nagios parser (#5601)

plugins/inputs/exec/exec.go

@@ -3,12 +3,12 @@ package exec
 import (
 	"bytes"
 	"fmt"
+	"log"
 	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"sync"
-	"syscall"
 	"time"
 
 	"github.com/kballard/go-shellquote"
@@ -61,39 +61,18 @@ func NewExec() *Exec {
 }
 
 type Runner interface {
-	Run(*Exec, string, telegraf.Accumulator) ([]byte, error)
+	Run(string, time.Duration) ([]byte, []byte, error)
 }
 
 type CommandRunner struct{}
 
-func AddNagiosState(exitCode error, acc telegraf.Accumulator) error {
-	nagiosState := 0
-	if exitCode != nil {
-		exiterr, ok := exitCode.(*exec.ExitError)
-		if ok {
-			status, ok := exiterr.Sys().(syscall.WaitStatus)
-			if ok {
-				nagiosState = status.ExitStatus()
-			} else {
-				return fmt.Errorf("exec: unable to get nagios plugin exit code")
-			}
-		} else {
-			return fmt.Errorf("exec: unable to get nagios plugin exit code")
-		}
-	}
-	fields := map[string]interface{}{"state": nagiosState}
-	acc.AddFields("nagios_state", fields, nil)
-	return nil
-}
-
 func (c CommandRunner) Run(
-	e *Exec,
 	command string,
-	acc telegraf.Accumulator,
-) ([]byte, error) {
+	timeout time.Duration,
+) ([]byte, []byte, error) {
 	split_cmd, err := shellquote.Split(command)
 	if err != nil || len(split_cmd) == 0 {
-		return nil, fmt.Errorf("exec: unable to parse command, %s", err)
+		return nil, nil, fmt.Errorf("exec: unable to parse command, %s", err)
 	}
 
 	cmd := exec.Command(split_cmd[0], split_cmd[1:]...)
@@ -105,44 +84,35 @@ func (c CommandRunner) Run(
 	cmd.Stdout = &out
 	cmd.Stderr = &stderr
 
-	if err := internal.RunTimeout(cmd, e.Timeout.Duration); err != nil {
-		switch e.parser.(type) {
-		case *nagios.NagiosParser:
-			AddNagiosState(err, acc)
-		default:
-			var errMessage = ""
-			if stderr.Len() > 0 {
-				stderr = removeCarriageReturns(stderr)
-				// Limit the number of bytes.
-				didTruncate := false
-				if stderr.Len() > MaxStderrBytes {
-					stderr.Truncate(MaxStderrBytes)
-					didTruncate = true
-				}
-				if i := bytes.IndexByte(stderr.Bytes(), '\n'); i > 0 {
-					// Only show truncation if the newline wasn't the last character.
-					if i < stderr.Len()-1 {
-						didTruncate = true
-					}
-					stderr.Truncate(i)
-				}
-				if didTruncate {
-					stderr.WriteString("...")
-				}
-
-				errMessage = fmt.Sprintf(": %s", stderr.String())
-			}
-			return nil, fmt.Errorf("exec: %s for command '%s'%s", err, command, errMessage)
-		}
-	} else {
-		switch e.parser.(type) {
-		case *nagios.NagiosParser:
-			AddNagiosState(nil, acc)
-		}
-	}
+	runErr := internal.RunTimeout(cmd, timeout)
 
 	out = removeCarriageReturns(out)
-	return out.Bytes(), nil
+	if stderr.Len() > 0 {
+		stderr = removeCarriageReturns(stderr)
+		stderr = truncate(stderr)
+	}
+
+	return out.Bytes(), stderr.Bytes(), runErr
+}
+
+func truncate(buf bytes.Buffer) bytes.Buffer {
+	// Limit the number of bytes.
+	didTruncate := false
+	if buf.Len() > MaxStderrBytes {
+		buf.Truncate(MaxStderrBytes)
+		didTruncate = true
+	}
+	if i := bytes.IndexByte(buf.Bytes(), '\n'); i > 0 {
+		// Only show truncation if the newline wasn't the last character.
+		if i < buf.Len()-1 {
+			didTruncate = true
+		}
+		buf.Truncate(i)
+	}
+	if didTruncate {
+		buf.WriteString("...")
+	}
+	return buf
 }
 
 // removeCarriageReturns removes all carriage returns from the input if the
@@ -173,9 +143,11 @@ func removeCarriageReturns(b bytes.Buffer) bytes.Buffer {
 
 func (e *Exec) ProcessCommand(command string, acc telegraf.Accumulator, wg *sync.WaitGroup) {
 	defer wg.Done()
+	_, isNagios := e.parser.(*nagios.NagiosParser)
 
-	out, err := e.runner.Run(e, command, acc)
-	if err != nil {
+	out, errbuf, runErr := e.runner.Run(command, e.Timeout.Duration)
+	if !isNagios && runErr != nil {
+		err := fmt.Errorf("exec: %s for command '%s': %s", runErr, command, string(errbuf))
 		acc.AddError(err)
 		return
 	}
@@ -183,11 +155,19 @@ func (e *Exec) ProcessCommand(command string, acc telegraf.Accumulator, wg *sync
 	metrics, err := e.parser.Parse(out)
 	if err != nil {
 		acc.AddError(err)
-	} else {
-		for _, metric := range metrics {
-			acc.AddFields(metric.Name(), metric.Fields(), metric.Tags(), metric.Time())
+		return
+	}
+
+	if isNagios {
+		metrics, err = nagios.TryAddState(runErr, metrics)
+		if err != nil {
+			log.Printf("E! [inputs.exec] failed to add nagios state: %s", err)
 		}
 	}
+
+	for _, m := range metrics {
+		acc.AddMetric(m)
+	}
 }
 
 func (e *Exec) SampleConfig() string {

plugins/inputs/exec/exec_test.go

@@ -5,8 +5,8 @@ import (
 	"fmt"
 	"runtime"
 	"testing"
+	"time"
 
-	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/parsers"
 
 	"github.com/influxdata/telegraf/testutil"
@@ -74,22 +74,21 @@ var crTests = []CarriageReturnTest{
 }
 
 type runnerMock struct {
-	out []byte
-	err error
+	out    []byte
+	errout []byte
+	err    error
 }
 
-func newRunnerMock(out []byte, err error) Runner {
+func newRunnerMock(out []byte, errout []byte, err error) Runner {
 	return &runnerMock{
-		out: out,
-		err: err,
+		out:    out,
+		errout: errout,
+		err:    err,
 	}
 }
 
-func (r runnerMock) Run(e *Exec, command string, acc telegraf.Accumulator) ([]byte, error) {
-	if r.err != nil {
-		return nil, r.err
-	}
-	return r.out, nil
+func (r runnerMock) Run(command string, _ time.Duration) ([]byte, []byte, error) {
+	return r.out, r.errout, r.err
 }
 
 func TestExec(t *testing.T) {
@@ -98,7 +97,7 @@ func TestExec(t *testing.T) {
 		MetricName: "exec",
 	})
 	e := &Exec{
-		runner:   newRunnerMock([]byte(validJson), nil),
+		runner:   newRunnerMock([]byte(validJson), nil, nil),
 		Commands: []string{"testcommand arg1"},
 		parser:   parser,
 	}
@@ -127,7 +126,7 @@ func TestExecMalformed(t *testing.T) {
 		MetricName: "exec",
 	})
 	e := &Exec{
-		runner:   newRunnerMock([]byte(malformedJson), nil),
+		runner:   newRunnerMock([]byte(malformedJson), nil, nil),
 		Commands: []string{"badcommand arg1"},
 		parser:   parser,
 	}
@@ -143,7 +142,7 @@ func TestCommandError(t *testing.T) {
 		MetricName: "exec",
 	})
 	e := &Exec{
-		runner:   newRunnerMock(nil, fmt.Errorf("exit status code 1")),
+		runner:   newRunnerMock(nil, nil, fmt.Errorf("exit status code 1")),
 		Commands: []string{"badcommand"},
 		parser:   parser,
 	}
@@ -201,6 +200,66 @@ func TestExecCommandWithoutGlobAndPath(t *testing.T) {
 	acc.AssertContainsFields(t, "metric", fields)
 }
 
+func TestTruncate(t *testing.T) {
+	tests := []struct {
+		name string
+		bufF func() *bytes.Buffer
+		expF func() *bytes.Buffer
+	}{
+		{
+			name: "should not truncate",
+			bufF: func() *bytes.Buffer {
+				var b bytes.Buffer
+				b.WriteString("hello world")
+				return &b
+			},
+			expF: func() *bytes.Buffer {
+				var b bytes.Buffer
+				b.WriteString("hello world")
+				return &b
+			},
+		},
+		{
+			name: "should truncate up to the new line",
+			bufF: func() *bytes.Buffer {
+				var b bytes.Buffer
+				b.WriteString("hello world\nand all the people")
+				return &b
+			},
+			expF: func() *bytes.Buffer {
+				var b bytes.Buffer
+				b.WriteString("hello world...")
+				return &b
+			},
+		},
+		{
+			name: "should truncate to the MaxStderrBytes",
+			bufF: func() *bytes.Buffer {
+				var b bytes.Buffer
+				for i := 0; i < 2*MaxStderrBytes; i++ {
+					b.WriteByte('b')
+				}
+				return &b
+			},
+			expF: func() *bytes.Buffer {
+				var b bytes.Buffer
+				for i := 0; i < MaxStderrBytes; i++ {
+					b.WriteByte('b')
+				}
+				b.WriteString("...")
+				return &b
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			res := truncate(*tt.bufF())
+			require.Equal(t, tt.expF().Bytes(), res.Bytes())
+		})
+	}
+}
+
 func TestRemoveCarriageReturns(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		// Test that all carriage returns are removed