cgroup2: enable resource limitation

enable resource limitation by disabling cgroup v1 warnings

resource limitation still doesn't work with rootless mode (even with systemd mode)

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

pkg/sysinfo/sysinfo_linux.go

@@ -60,6 +60,9 @@ func New(quiet bool) *SysInfo {
 		w := o(sysInfo, cgMounts)
 		warnings = append(warnings, w...)
 	}
+	if cgroups.IsCgroup2UnifiedMode() {
+		warnings = append(warnings, "Your system is running cgroup v2 (unsupported)")
+	}
 	if !quiet {
 		for _, w := range warnings {
 			logrus.Warn(w)
@@ -70,6 +73,15 @@ func New(quiet bool) *SysInfo {
 
 // applyMemoryCgroupInfo reads the memory information from the memory cgroup mount point.
 func applyMemoryCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
+	if cgroups.IsCgroup2UnifiedMode() {
+		// TODO: check cgroup2 info correctly
+		info.MemoryLimit = true
+		info.SwapLimit = true
+		info.MemoryReservation = true
+		info.OomKillDisable = true
+		info.MemorySwappiness = true
+		return nil
+	}
 	var warnings []string
 	mountPoint, ok := cgMounts["memory"]
 	if !ok {
@@ -108,6 +120,15 @@ func applyMemoryCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
 
 // applyCPUCgroupInfo reads the cpu information from the cpu cgroup mount point.
 func applyCPUCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
+	if cgroups.IsCgroup2UnifiedMode() {
+		// TODO: check cgroup2 info correctly
+		info.CPUShares = true
+		info.CPUCfsPeriod = true
+		info.CPUCfsQuota = true
+		info.CPURealtimePeriod = true
+		info.CPURealtimeRuntime = true
+		return nil
+	}
 	var warnings []string
 	mountPoint, ok := cgMounts["cpu"]
 	if !ok {
@@ -145,6 +166,15 @@ func applyCPUCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
 
 // applyBlkioCgroupInfo reads the blkio information from the blkio cgroup mount point.
 func applyBlkioCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
+	if cgroups.IsCgroup2UnifiedMode() {
+		// TODO: check cgroup2 info correctly
+		info.BlkioWeight = true
+		info.BlkioReadBpsDevice = true
+		info.BlkioWriteBpsDevice = true
+		info.BlkioReadIOpsDevice = true
+		info.BlkioWriteIOpsDevice = true
+		return nil
+	}
 	var warnings []string
 	mountPoint, ok := cgMounts["blkio"]
 	if !ok {
@@ -186,6 +216,11 @@ func applyBlkioCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
 
 // applyCPUSetCgroupInfo reads the cpuset information from the cpuset cgroup mount point.
 func applyCPUSetCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
+	if cgroups.IsCgroup2UnifiedMode() {
+		// TODO: check cgroup2 info correctly
+		info.Cpuset = true
+		return nil
+	}
 	var warnings []string
 	mountPoint, ok := cgMounts["cpuset"]
 	if !ok {
@@ -213,6 +248,11 @@ func applyCPUSetCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
 
 // applyPIDSCgroupInfo reads the pids information from the pids cgroup mount point.
 func applyPIDSCgroupInfo(info *SysInfo, _ map[string]string) []string {
+	if cgroups.IsCgroup2UnifiedMode() {
+		// TODO: check cgroup2 info correctly
+		info.PidsLimit = true
+		return nil
+	}
 	var warnings []string
 	_, err := cgroups.FindCgroupMountpoint("", "pids")
 	if err != nil {
@@ -225,6 +265,11 @@ func applyPIDSCgroupInfo(info *SysInfo, _ map[string]string) []string {
 
 // applyDevicesCgroupInfo reads the pids information from the devices cgroup mount point.
 func applyDevicesCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
+	if cgroups.IsCgroup2UnifiedMode() {
+		// TODO: check cgroup2 info correctly
+		info.CgroupDevicesEnabled = true
+		return nil
+	}
 	var warnings []string
 	_, ok := cgMounts["devices"]
 	info.CgroupDevicesEnabled = ok