Modernize code

devices/systemd.go

@@ -166,7 +166,7 @@ func systemdProperties(r *cgroups.Resources, sdVer int) ([]systemdDbus.Property,
 	return properties, nil
 }
 
-func newProp(name string, units interface{}) systemdDbus.Property {
+func newProp(name string, units any) systemdDbus.Property {
 	return systemdDbus.Property{
 		Name:  name,
 		Value: dbus.MakeVariant(units),

devices/systemd_test.go

@@ -95,7 +95,7 @@ func TestPodSkipDevicesUpdate(t *testing.T) {
 	}
 
 	// Now update the pod a few times.
-	for i := 0; i < 42; i++ {
+	for range 42 {
 		podConfig.Resources.PidsLimit++
 		podConfig.Resources.Memory += 1024 * 1024
 		if err := pm.Set(podConfig.Resources); err != nil {

file_test.go

@@ -32,7 +32,7 @@ func TestWriteCgroupFileHandlesInterrupt(t *testing.T) {
 		t.Skip(err)
 	}
 
-	for i := 0; i < 100000; i++ {
+	for i := range 100000 {
 		limit := 1024*1024 + i
 		if err := WriteFile(cgroupPath, memoryLimit, strconv.Itoa(limit)); err != nil {
 			t.Fatalf("Failed to write %d on attempt %d: %+v", limit, i, err)

fs/blkio_test.go

@@ -1,6 +1,7 @@
 package fs
 
 import (
+	"maps"
 	"strconv"
 	"testing"
 
@@ -465,10 +466,7 @@ func TestBlkioStatsNoFilesBFQDebug(t *testing.T) {
 	for _, testCase := range testCases {
 		path := tempDir(t, "cpuset")
 
-		tempBlkioTestFiles := map[string]string{}
-		for i, v := range blkioBFQDebugStatsTestFiles {
-			tempBlkioTestFiles[i] = v
-		}
+		tempBlkioTestFiles := maps.Clone(blkioBFQDebugStatsTestFiles)
 		delete(tempBlkioTestFiles, testCase.filename)
 
 		writeFileContents(t, path, tempBlkioTestFiles)
@@ -579,10 +577,7 @@ func TestBlkioStatsNoFilesCFQ(t *testing.T) {
 	for _, testCase := range testCases {
 		path := tempDir(t, "cpuset")
 
-		tempBlkioTestFiles := map[string]string{}
-		for i, v := range blkioCFQStatsTestFiles {
-			tempBlkioTestFiles[i] = v
-		}
+		tempBlkioTestFiles := maps.Clone(blkioCFQStatsTestFiles)
 		delete(tempBlkioTestFiles, testCase.filename)
 
 		writeFileContents(t, path, tempBlkioTestFiles)

fs/cpuset_test.go

@@ -1,6 +1,7 @@
 package fs
 
 import (
+	"maps"
 	"reflect"
 	"testing"
 
@@ -211,10 +212,7 @@ func TestCPUSetStatsMissingFiles(t *testing.T) {
 		t.Run(testCase.desc, func(t *testing.T) {
 			path := tempDir(t, "cpuset")
 
-			tempCpusetTestFiles := map[string]string{}
-			for i, v := range cpusetTestFiles {
-				tempCpusetTestFiles[i] = v
-			}
+			tempCpusetTestFiles := maps.Clone(cpusetTestFiles)
 
 			if testCase.removeFile {
 				delete(tempCpusetTestFiles, testCase.filename)

fs/freezer.go

@@ -57,7 +57,7 @@ func (s *FreezerGroup) Set(path string, r *cgroups.Resources) (Err error) {
 		// Alas, this is still a game of chances, since the real fix
 		// belong to the kernel (cgroup v2 do not have this bug).
 
-		for i := 0; i < 1000; i++ {
+		for i := range 1000 {
 			if i%50 == 49 {
 				// Occasional thaw and sleep improves
 				// the chances to succeed in freezing

systemd/common.go

@@ -89,7 +89,7 @@ func ExpandSlice(slice string) (string, error) {
 	return path, nil
 }
 
-func newProp(name string, units interface{}) systemdDbus.Property {
+func newProp(name string, units any) systemdDbus.Property {
 	return systemdDbus.Property{
 		Name:  name,
 		Value: dbus.MakeVariant(units),
@@ -266,7 +266,7 @@ func systemdVersionAtoi(str string) (int, error) {
 	// Unconditionally remove the leading prefix ("v).
 	str = strings.TrimLeft(str, `"v`)
 	// Match on the first integer we can grab.
-	for i := 0; i < len(str); i++ {
+	for i := range len(str) {
 		if str[i] < '0' || str[i] > '9' {
 			// First non-digit: cut the tail.
 			str = str[:i]

systemd/systemd_test.go

@@ -90,7 +90,7 @@ func TestUnitExistsIgnored(t *testing.T) {
 	pm := newManager(t, podConfig)
 
 	// create twice to make sure "UnitExists" error is ignored.
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		if err := pm.Apply(-1); err != nil {
 			t.Fatal(err)
 		}

utils.go

@@ -395,7 +395,7 @@ func WriteCgroupProc(dir string, pid int) error {
 	}
 	defer file.Close()
 
-	for i := 0; i < 5; i++ {
+	for range 5 {
 		_, err = file.WriteString(strconv.Itoa(pid))
 		if err == nil {
 			return nil

utils_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"path/filepath"
 	"reflect"
+	"slices"
 	"strings"
 	"testing"
 
@@ -273,14 +274,7 @@ func TestGetCgroupMounts(t *testing.T) {
 			if !strings.HasPrefix(m.Mountpoint, "/sys/fs/cgroup/") && !strings.Contains(m.Mountpoint, ss) {
 				t.Fatalf("unexpected mountpoint for %s: %s", ss, m.Mountpoint)
 			}
-			var ssFound bool
-			for _, mss := range m.Subsystems {
-				if mss == ss {
-					ssFound = true
-					break
-				}
-			}
-			if !ssFound {
+			if !slices.Contains(m.Subsystems, ss) {
 				t.Fatalf("subsystem %s not found in Subsystems field %v", ss, m.Subsystems)
 			}
 		}

v1_utils.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 	"sync"
 	"syscall"
@@ -144,10 +145,8 @@ func FindCgroupMountpointAndRoot(cgroupPath, subsystem string) (string, string,
 func findCgroupMountpointAndRootFromMI(mounts []*mountinfo.Info, cgroupPath, subsystem string) (string, string, error) {
 	for _, mi := range mounts {
 		if strings.HasPrefix(mi.Mountpoint, cgroupPath) {
-			for _, opt := range strings.Split(mi.VFSOptions, ",") {
-				if opt == subsystem {
-					return mi.Mountpoint, mi.Root, nil
-				}
+			if slices.Contains(strings.Split(mi.VFSOptions, ","), subsystem) {
+				return mi.Mountpoint, mi.Root, nil
 			}
 		}
 	}