Improve ipvs input error strings and logging (#6530)

plugins/inputs/ipvs/ipvs.go

@@ -3,7 +3,6 @@
 package ipvs
 
 import (
-	"errors"
 	"fmt"
 	"math/bits"
 	"strconv"
@@ -11,6 +10,7 @@ import (
 
 	"github.com/docker/libnetwork/ipvs"
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/common/logrus"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
 
@@ -35,7 +35,7 @@ func (i *IPVS) Gather(acc telegraf.Accumulator) error {
 	if i.handle == nil {
 		h, err := ipvs.New("") // TODO: make the namespace configurable
 		if err != nil {
-			return errors.New("Unable to open IPVS handle")
+			return fmt.Errorf("unable to open IPVS handle: %v", err)
 		}
 		i.handle = h
 	}
@@ -44,7 +44,7 @@ func (i *IPVS) Gather(acc telegraf.Accumulator) error {
 	if err != nil {
 		i.handle.Close()
 		i.handle = nil // trigger a reopen on next call to gather
-		return errors.New("Failed to list IPVS services")
+		return fmt.Errorf("failed to list IPVS services: %v", err)
 	}
 	for _, s := range services {
 		fields := map[string]interface{}{
@@ -61,7 +61,7 @@ func (i *IPVS) Gather(acc telegraf.Accumulator) error {
 
 		destinations, err := i.handle.GetDestinations(s)
 		if err != nil {
-			i.Log.Errorf("Failed to list destinations for a virtual server: %s", err.Error())
+			i.Log.Errorf("Failed to list destinations for a virtual server: %v", err)
 			continue // move on to the next virtual server
 		}
 
@@ -148,5 +148,8 @@ func addressFamilyToString(af uint16) string {
 }
 
 func init() {
-	inputs.Add("ipvs", func() telegraf.Input { return &IPVS{} })
+	inputs.Add("ipvs", func() telegraf.Input {
+		logrus.InstallHook()
+		return &IPVS{}
+	})
 }