Merge pull request #3003 from alexandear/refactor/sync-once-values

sysprof,osutil: simplify with sync.OnceValues

Author: jandubois

pkg/osutil/machineid.go

@@ -14,27 +14,18 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-var (
-	machineIDCached string
-	machineIDOnce   sync.Once
-)
-
-func MachineID() string {
-	machineIDOnce.Do(func() {
-		x, err := machineID()
-		if err == nil && x != "" {
-			machineIDCached = x
-			return
-		}
-		logrus.WithError(err).Debug("failed to get machine ID, falling back to use hostname instead")
-		hostname, err := os.Hostname()
-		if err != nil {
-			panic(err)
-		}
-		machineIDCached = hostname
-	})
-	return machineIDCached
-}
+var MachineID = sync.OnceValue(func() string {
+	x, err := machineID()
+	if err == nil && x != "" {
+		return x
+	}
+	logrus.WithError(err).Debug("failed to get machine ID, falling back to use hostname instead")
+	hostname, err := os.Hostname()
+	if err != nil {
+		panic(fmt.Errorf("failed to get hostname: %w", err))
+	}
+	return hostname
+})
 
 func machineID() (string, error) {
 	if runtime.GOOS == "darwin" {

pkg/sysprof/sysprof_darwin.go

@@ -11,22 +11,17 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-var (
-	networkDataOnce   sync.Once
-	networkDataCached SPNetworkDataType
-	networkDataError  error
-)
-
-func NetworkData() ([]NetworkDataType, error) {
-	networkDataOnce.Do(func() {
-		var jsonBytes []byte
-		jsonBytes, networkDataError = SystemProfiler("SPNetworkDataType")
-		if networkDataError == nil {
-			networkDataError = json.Unmarshal(jsonBytes, &networkDataCached)
-		}
-	})
-	return networkDataCached.SPNetworkDataType, networkDataError
-}
+var NetworkData = sync.OnceValues(func() ([]NetworkDataType, error) {
+	b, err := SystemProfiler("SPNetworkDataType")
+	if err != nil {
+		return nil, err
+	}
+	var networkData SPNetworkDataType
+	if err := json.Unmarshal(b, &networkData); err != nil {
+		return nil, err
+	}
+	return networkData.SPNetworkDataType, nil
+})
 
 func SystemProfiler(dataType string) ([]byte, error) {
 	exe, err := exec.LookPath("system_profiler")