fix tests

pkg/util/runtime/cpu_linux.go

@@ -36,21 +36,41 @@ import (
 //
 //	https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt
 func NumCPU() int {
+	return NumCPUWithCustomPath("")
+}
+
+func NumCPUWithCustomPath(path string) int {
 	cpus := runtime.NumCPU()
 
-	cgroupVersion := GetCgroupVersion()
+	cgroupVersionCheckPath := path
+
+	if cgroupVersionCheckPath == "" {
+		cgroupVersionCheckPath = "/sys/fs/cgroup/"
+	}
+
+	cgroupVersion := GetCgroupVersion(cgroupVersionCheckPath)
 	cpuQuota := int64(-1)
 	cpuPeriod := int64(-1)
 
 	if cgroupVersion == 1 {
-		cgroupPath, err := libcontainercgroups.FindCgroupMountpoint("", "cpu")
-		if err != nil {
-			return cpus
+		cgroupPath := ""
+		if path == "" {
+			cgroupPathRd, err := libcontainercgroups.FindCgroupMountpoint("", "cpu")
+			if err != nil {
+				return cpus
+			}
+			cgroupPath = cgroupPathRd
+		} else {
+			cgroupPath = path
 		}
 		cpuQuota = readCgroupFileToInt64(cgroupPath, "cpu.cfs_quota_us")
 		cpuPeriod = readCgroupFileToInt64(cgroupPath, "cpu.cfs_period_us")
 	} else if cgroupVersion == 2 {
-		cpuQuota, cpuPeriod = readCgroup2FileToInt64Tuple("cpu.max")
+		cgroupPath := "/sys/fs/cgroup/"
+		if path != "" {
+			cgroupPath = path
+		}
+		cpuQuota, cpuPeriod = readCgroup2FileToInt64Tuple(cgroupPath, "cpu.max")
 	}
 
 	if cpuQuota == -1 || cpuPeriod == -1 {
@@ -60,26 +80,21 @@ func NumCPU() int {
 	return int(math.Ceil(float64(cpuQuota) / float64(cpuPeriod)))
 }
 
-func GetCgroupVersion() int64 {
+func GetCgroupVersion(cgroupPath string) int64 {
 	// /sys/fs/cgroup/cgroup.controllers will not exist with cgroupsv1
-	if _, err := os.Stat("/sys/fs/cgroup/cgroup.controllers"); err == nil {
+	if _, err := os.Stat(filepath.Join(cgroupPath, "cgroup.controllers")); err == nil {
 		return 2
 	}
 
 	return 1
 }
 
-func readCgroup2FileToInt64Tuple(cgroupFile string) (quota, period int64) {
-	contents, err := os.ReadFile(filepath.Join(string(os.PathSeparator), "sys", "fs", "cgroup", cgroupFile))
-	if err != nil {
-		return -1, -1
-	}
-
+func readCgroup2StringToInt64Tuple(cgroupString string) (quota, period int64) {
 	// file contents looks like: $MAX $PERIOD
 	// $MAX can have value "max" indicating no limit
 	// it is possible for $PERIOD to be unset
 
-	values := strings.Fields(string(contents))
+	values := strings.Fields(cgroupString)
 
 	if values[0] == "max" {
 		return -1, -1
@@ -102,16 +117,29 @@ func readCgroup2FileToInt64Tuple(cgroupFile string) (quota, period int64) {
 	return cpuQuota, cpuPeriod
 }
 
-func readCgroupFileToInt64(cgroupPath, cgroupFile string) int64 {
+func readCgroup2FileToInt64Tuple(cgroupPath, cgroupFile string) (quota, period int64) {
 	contents, err := os.ReadFile(filepath.Join(cgroupPath, cgroupFile))
 	if err != nil {
-		return -1
+		return -1, -1
 	}
 
-	strValue := strings.TrimSpace(string(contents))
+	return readCgroup2StringToInt64Tuple(string(contents))
+}
+
+func readCgroupStringToInt64(contents string) int64 {
+	strValue := strings.TrimSpace(contents)
 	if value, err := strconv.ParseInt(strValue, 10, 64); err == nil {
 		return value
 	}
 
 	return -1
 }
+
+func readCgroupFileToInt64(cgroupPath, cgroupFile string) int64 {
+	contents, err := os.ReadFile(filepath.Join(cgroupPath, cgroupFile))
+	if err != nil {
+		return -1
+	}
+
+	return readCgroupStringToInt64(string(contents))
+}