Merge pull request #42639 from thaJeztah/system_info_clean

pkg/sysinfo: assorted cleanup/refactoring for handling warnings and logging

api/types/types.go

@@ -212,7 +212,12 @@ type Info struct {
 	SecurityOptions     []string
 	ProductLicense      string               `json:",omitempty"`
 	DefaultAddressPools []NetworkAddressPool `json:",omitempty"`
-	Warnings            []string
+
+	// Warnings contains a slice of warnings that occurred  while collecting
+	// system information. These warnings are intended to be informational
+	// messages for the user, and are not intended to be parsed / used for
+	// other purposes, as they do not have a fixed format.
+	Warnings []string
 }
 
 // KeyValue holds a key/value pair

cmd/dockerd/daemon.go

@@ -478,14 +478,14 @@ func warnOnDeprecatedConfigOptions(config *config.Config) {
 func initRouter(opts routerOptions) {
 	decoder := runconfig.ContainerDecoder{
 		GetSysInfo: func() *sysinfo.SysInfo {
-			return opts.daemon.RawSysInfo(true)
+			return opts.daemon.RawSysInfo()
 		},
 	}
 
 	routers := []router.Router{
 		// we need to add the checkpoint router before the container router or the DELETE gets masked
 		checkpointrouter.NewRouter(opts.daemon, decoder),
-		container.NewRouter(opts.daemon, decoder, opts.daemon.RawSysInfo(true).CgroupUnified),
+		container.NewRouter(opts.daemon, decoder, opts.daemon.RawSysInfo().CgroupUnified),
 		image.NewRouter(opts.daemon.ImageService()),
 		systemrouter.NewRouter(opts.daemon, opts.cluster, opts.buildkit, opts.features),
 		volume.NewRouter(opts.daemon.VolumesService()),

daemon/daemon.go

@@ -1050,7 +1050,10 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 		return nil, err
 	}
 
-	sysInfo := d.RawSysInfo(false)
+	sysInfo := d.RawSysInfo()
+	for _, w := range sysInfo.Warnings {
+		logrus.Warn(w)
+	}
 	// Check if Devices cgroup is mounted, it is hard requirement for container security,
 	// on Linux.
 	if runtime.GOOS == "linux" && !sysInfo.CgroupDevicesEnabled && !userns.RunningInUserNS() {

daemon/daemon_unix.go

@@ -666,7 +666,7 @@ func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *containertypes.
 	if hostConfig == nil {
 		return nil, nil
 	}
-	sysInfo := daemon.RawSysInfo(true)
+	sysInfo := daemon.RawSysInfo()
 
 	w, err := verifyPlatformContainerResources(&hostConfig.Resources, sysInfo, update)
 
@@ -1718,14 +1718,14 @@ func (daemon *Daemon) setupSeccompProfile() error {
 }
 
 // RawSysInfo returns *sysinfo.SysInfo .
-func (daemon *Daemon) RawSysInfo(quiet bool) *sysinfo.SysInfo {
+func (daemon *Daemon) RawSysInfo() *sysinfo.SysInfo {
 	var siOpts []sysinfo.Opt
 	if daemon.getCgroupDriver() == cgroupSystemdDriver {
 		if euid := os.Getenv("ROOTLESSKIT_PARENT_EUID"); euid != "" {
 			siOpts = append(siOpts, sysinfo.WithCgroup2GroupPath("/user.slice/user-"+euid+".slice"))
 		}
 	}
-	return sysinfo.New(quiet, siOpts...)
+	return sysinfo.New(siOpts...)
 }
 
 func recursiveUnmount(target string) error {

daemon/daemon_unsupported.go

@@ -13,6 +13,6 @@ func setupResolvConf(config *config.Config) {
 }
 
 // RawSysInfo returns *sysinfo.SysInfo .
-func (daemon *Daemon) RawSysInfo(quiet bool) *sysinfo.SysInfo {
-	return sysinfo.New(quiet)
+func (daemon *Daemon) RawSysInfo() *sysinfo.SysInfo {
+	return sysinfo.New()
 }

daemon/daemon_windows.go

@@ -652,6 +652,6 @@ func setupResolvConf(config *config.Config) {
 }
 
 // RawSysInfo returns *sysinfo.SysInfo .
-func (daemon *Daemon) RawSysInfo(quiet bool) *sysinfo.SysInfo {
-	return sysinfo.New(quiet)
+func (daemon *Daemon) RawSysInfo() *sysinfo.SysInfo {
+	return sysinfo.New()
 }

daemon/info.go

@@ -30,7 +30,7 @@ import (
 func (daemon *Daemon) SystemInfo() *types.Info {
 	defer metrics.StartTimer(hostInfoFunctions.WithValues("system_info"))()
 
-	sysInfo := daemon.RawSysInfo(true)
+	sysInfo := daemon.RawSysInfo()
 	cRunning, cPaused, cStopped := stateCtr.get()
 
 	v := &types.Info{

daemon/oci_linux.go

@@ -824,7 +824,7 @@ func WithCgroups(daemon *Daemon, c *container.Container) coci.SpecOpts {
 		}
 
 		// FIXME this is very expensive way to check if cpu rt is supported
-		sysInfo := daemon.RawSysInfo(true)
+		sysInfo := daemon.RawSysInfo()
 		if !sysInfo.CPURealtime {
 			return errors.New("daemon-scoped cpu-rt-period and cpu-rt-runtime are not supported by the kernel")
 		}

integration-cli/docker_cli_run_unix_test.go

@@ -699,7 +699,7 @@ func (s *DockerSuite) TestRunSwapLessThanMemoryLimit(c *testing.T) {
 func (s *DockerSuite) TestRunInvalidCpusetCpusFlagValue(c *testing.T) {
 	testRequires(c, cgroupCpuset, testEnv.IsLocalDaemon)
 
-	sysInfo := sysinfo.New(true)
+	sysInfo := sysinfo.New()
 	cpus, err := parsers.ParseUintList(sysInfo.Cpus)
 	assert.NilError(c, err)
 	var invalid int
@@ -718,7 +718,7 @@ func (s *DockerSuite) TestRunInvalidCpusetCpusFlagValue(c *testing.T) {
 func (s *DockerSuite) TestRunInvalidCpusetMemsFlagValue(c *testing.T) {
 	testRequires(c, cgroupCpuset)
 
-	sysInfo := sysinfo.New(true)
+	sysInfo := sysinfo.New()
 	mems, err := parsers.ParseUintList(sysInfo.Mems)
 	assert.NilError(c, err)
 	var invalid int

integration-cli/requirements_unix_test.go

@@ -84,6 +84,6 @@ func overlayFSSupported() bool {
 
 func init() {
 	if testEnv.IsLocalDaemon() {
-		SysInfo = sysinfo.New(true)
+		SysInfo = sysinfo.New()
 	}
 }

pkg/sysinfo/cgroup2_linux.go

@@ -12,58 +12,46 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-type infoCollectorV2 func(info *SysInfo, controllers map[string]struct{}, dirPath string) (warnings []string)
-
-func newV2(quiet bool, opts *opts) *SysInfo {
-	var warnings []string
+func newV2(options ...Opt) *SysInfo {
 	sysInfo := &SysInfo{
 		CgroupUnified: true,
+		cg2GroupPath:  "/",
 	}
-	g := opts.cg2GroupPath
-	if g == "" {
-		g = "/"
+	for _, o := range options {
+		o(sysInfo)
+	}
+
+	ops := []infoCollector{
+		applyNetworkingInfo,
+		applyAppArmorInfo,
+		applySeccompInfo,
+		applyCgroupNsInfo,
 	}
-	m, err := cgroupsV2.LoadManager("/sys/fs/cgroup", g)
+
+	m, err := cgroupsV2.LoadManager("/sys/fs/cgroup", sysInfo.cg2GroupPath)
 	if err != nil {
 		logrus.Warn(err)
 	} else {
-		controllersM := make(map[string]struct{})
+		sysInfo.cg2Controllers = make(map[string]struct{})
 		controllers, err := m.Controllers()
 		if err != nil {
 			logrus.Warn(err)
 		}
 		for _, c := range controllers {
-			controllersM[c] = struct{}{}
+			sysInfo.cg2Controllers[c] = struct{}{}
 		}
-		opsV2 := []infoCollectorV2{
+		ops = append(ops,
 			applyMemoryCgroupInfoV2,
 			applyCPUCgroupInfoV2,
 			applyIOCgroupInfoV2,
 			applyCPUSetCgroupInfoV2,
 			applyPIDSCgroupInfoV2,
 			applyDevicesCgroupInfoV2,
-		}
-		dirPath := path.Join("/sys/fs/cgroup", path.Clean(g))
-		for _, o := range opsV2 {
-			w := o(sysInfo, controllersM, dirPath)
-			warnings = append(warnings, w...)
-		}
+		)
 	}
 
-	ops := []infoCollector{
-		applyNetworkingInfo,
-		applyAppArmorInfo,
-		applySeccompInfo,
-		applyCgroupNsInfo,
-	}
 	for _, o := range ops {
-		w := o(sysInfo, nil)
-		warnings = append(warnings, w...)
-	}
-	if !quiet {
-		for _, w := range warnings {
-			logrus.Warn(w)
-		}
+		o(sysInfo)
 	}
 	return sysInfo
 }
@@ -86,11 +74,10 @@ func getSwapLimitV2() bool {
 	return true
 }
 
-func applyMemoryCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, _ string) []string {
-	var warnings []string
-	if _, ok := controllers["memory"]; !ok {
-		warnings = append(warnings, "Unable to find memory controller")
-		return warnings
+func applyMemoryCgroupInfoV2(info *SysInfo) {
+	if _, ok := info.cg2Controllers["memory"]; !ok {
+		info.Warnings = append(info.Warnings, "Unable to find memory controller")
+		return
 	}
 
 	info.MemoryLimit = true
@@ -100,26 +87,22 @@ func applyMemoryCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, _ s
 	info.MemorySwappiness = false
 	info.KernelMemory = false
 	info.KernelMemoryTCP = false
-	return warnings
 }
 
-func applyCPUCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, _ string) []string {
-	var warnings []string
-	if _, ok := controllers["cpu"]; !ok {
-		warnings = append(warnings, "Unable to find cpu controller")
-		return warnings
+func applyCPUCgroupInfoV2(info *SysInfo) {
+	if _, ok := info.cg2Controllers["cpu"]; !ok {
+		info.Warnings = append(info.Warnings, "Unable to find cpu controller")
+		return
 	}
 	info.CPUShares = true
 	info.CPUCfs = true
 	info.CPURealtime = false
-	return warnings
 }
 
-func applyIOCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, _ string) []string {
-	var warnings []string
-	if _, ok := controllers["io"]; !ok {
-		warnings = append(warnings, "Unable to find io controller")
-		return warnings
+func applyIOCgroupInfoV2(info *SysInfo) {
+	if _, ok := info.cg2Controllers["io"]; !ok {
+		info.Warnings = append(info.Warnings, "Unable to find io controller")
+		return
 	}
 
 	info.BlkioWeight = true
@@ -128,42 +111,36 @@ func applyIOCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, _ strin
 	info.BlkioWriteBpsDevice = true
 	info.BlkioReadIOpsDevice = true
 	info.BlkioWriteIOpsDevice = true
-	return warnings
 }
 
-func applyCPUSetCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, dirPath string) []string {
-	var warnings []string
-	if _, ok := controllers["cpuset"]; !ok {
-		warnings = append(warnings, "Unable to find cpuset controller")
-		return warnings
+func applyCPUSetCgroupInfoV2(info *SysInfo) {
+	if _, ok := info.cg2Controllers["cpuset"]; !ok {
+		info.Warnings = append(info.Warnings, "Unable to find cpuset controller")
+		return
 	}
 	info.Cpuset = true
 
-	cpus, err := ioutil.ReadFile(path.Join(dirPath, "cpuset.cpus.effective"))
+	cpus, err := ioutil.ReadFile(path.Join("/sys/fs/cgroup", info.cg2GroupPath, "cpuset.cpus.effective"))
 	if err != nil {
-		return warnings
+		return
 	}
 	info.Cpus = strings.TrimSpace(string(cpus))
 
-	mems, err := ioutil.ReadFile(path.Join(dirPath, "cpuset.mems.effective"))
+	mems, err := ioutil.ReadFile(path.Join("/sys/fs/cgroup", info.cg2GroupPath, "cpuset.mems.effective"))
 	if err != nil {
-		return warnings
+		return
 	}
 	info.Mems = strings.TrimSpace(string(mems))
-	return warnings
 }
 
-func applyPIDSCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, _ string) []string {
-	var warnings []string
-	if _, ok := controllers["pids"]; !ok {
-		warnings = append(warnings, "Unable to find pids controller")
-		return warnings
+func applyPIDSCgroupInfoV2(info *SysInfo) {
+	if _, ok := info.cg2Controllers["pids"]; !ok {
+		info.Warnings = append(info.Warnings, "Unable to find pids controller")
+		return
 	}
 	info.PidsLimit = true
-	return warnings
 }
 
-func applyDevicesCgroupInfoV2(info *SysInfo, controllers map[string]struct{}, _ string) []string {
+func applyDevicesCgroupInfoV2(info *SysInfo) {
 	info.CgroupDevicesEnabled = !userns.RunningInUserNS()
-	return nil
 }

pkg/sysinfo/sysinfo.go

@@ -2,6 +2,9 @@ package sysinfo // import "github.com/docker/docker/pkg/sysinfo"
 
 import "github.com/docker/docker/pkg/parsers"
 
+// Opt for New().
+type Opt func(info *SysInfo)
+
 // SysInfo stores information about which features a kernel supports.
 // TODO Windows: Factor out platform specific capabilities.
 type SysInfo struct {
@@ -33,6 +36,23 @@ type SysInfo struct {
 
 	// Whether the cgroup is in unified mode (v2).
 	CgroupUnified bool
+
+	// Warnings contains a slice of warnings that occurred  while collecting
+	// system information. These warnings are intended to be informational
+	// messages for the user, and can either be logged or returned to the
+	// client; they are not intended to be parsed / used for other purposes,
+	// and do not have a fixed format.
+	Warnings []string
+
+	// cgMounts is the list of cgroup v1 mount paths, indexed by subsystem, to
+	// inspect availability of subsystems.
+	cgMounts map[string]string
+
+	// cg2GroupPath is the cgroup v2 group path to inspect availability of the controllers.
+	cg2GroupPath string
+
+	// cg2Controllers is an index of available cgroup v2 controllers.
+	cg2Controllers map[string]struct{}
 }
 
 type cgroupMemInfo struct {

pkg/sysinfo/sysinfo_linux.go

@@ -28,14 +28,7 @@ func findCgroupMountpoints() (map[string]string, error) {
 	return mps, nil
 }
 
-type infoCollector func(info *SysInfo, cgMounts map[string]string) (warnings []string)
-
-type opts struct {
-	cg2GroupPath string
-}
-
-// Opt for New().
-type Opt func(*opts)
+type infoCollector func(info *SysInfo)
 
 // WithCgroup2GroupPath specifies the cgroup v2 group path to inspect availability
 // of the controllers.
@@ -44,172 +37,158 @@ type Opt func(*opts)
 //
 // e.g. g = "/user.slice/user-1000.slice/user@1000.service"
 func WithCgroup2GroupPath(g string) Opt {
-	return func(o *opts) {
-		o.cg2GroupPath = path.Clean(g)
+	return func(o *SysInfo) {
+		if p := path.Clean(g); p != "" {
+			o.cg2GroupPath = p
+		}
 	}
 }
 
 // New returns a new SysInfo, using the filesystem to detect which features
-// the kernel supports. If `quiet` is `false` warnings are printed in logs
-// whenever an error occurs or misconfigurations are present.
-func New(quiet bool, options ...Opt) *SysInfo {
-	var opts opts
-	for _, o := range options {
-		o(&opts)
-	}
+// the kernel supports.
+func New(options ...Opt) *SysInfo {
 	if cdcgroups.Mode() == cdcgroups.Unified {
-		return newV2(quiet, &opts)
+		return newV2(options...)
+	}
+	return newV1()
+}
+
+func newV1() *SysInfo {
+	var (
+		err     error
+		sysInfo = &SysInfo{}
+	)
+
+	ops := []infoCollector{
+		applyNetworkingInfo,
+		applyAppArmorInfo,
+		applySeccompInfo,
+		applyCgroupNsInfo,
 	}
 
-	var ops []infoCollector
-	var warnings []string
-	sysInfo := &SysInfo{}
-	cgMounts, err := findCgroupMountpoints()
+	sysInfo.cgMounts, err = findCgroupMountpoints()
 	if err != nil {
 		logrus.Warn(err)
 	} else {
-		ops = append(ops, []infoCollector{
+		ops = append(ops,
 			applyMemoryCgroupInfo,
 			applyCPUCgroupInfo,
 			applyBlkioCgroupInfo,
 			applyCPUSetCgroupInfo,
 			applyPIDSCgroupInfo,
 			applyDevicesCgroupInfo,
-		}...)
+		)
 	}
 
-	ops = append(ops, []infoCollector{
-		applyNetworkingInfo,
-		applyAppArmorInfo,
-		applySeccompInfo,
-		applyCgroupNsInfo,
-	}...)
-
 	for _, o := range ops {
-		w := o(sysInfo, cgMounts)
-		warnings = append(warnings, w...)
-	}
-	if !quiet {
-		for _, w := range warnings {
-			logrus.Warn(w)
-		}
+		o(sysInfo)
 	}
 	return sysInfo
 }
 
 // applyMemoryCgroupInfo adds the memory cgroup controller information to the info.
-func applyMemoryCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
-	var warnings []string
-	mountPoint, ok := cgMounts["memory"]
+func applyMemoryCgroupInfo(info *SysInfo) {
+	mountPoint, ok := info.cgMounts["memory"]
 	if !ok {
-		warnings = append(warnings, "Your kernel does not support cgroup memory limit")
-		return warnings
+		info.Warnings = append(info.Warnings, "Your kernel does not support cgroup memory limit")
+		return
 	}
 	info.MemoryLimit = ok
 
 	info.SwapLimit = cgroupEnabled(mountPoint, "memory.memsw.limit_in_bytes")
 	if !info.SwapLimit {
-		warnings = append(warnings, "Your kernel does not support swap memory limit")
+		info.Warnings = append(info.Warnings, "Your kernel does not support swap memory limit")
 	}
 	info.MemoryReservation = cgroupEnabled(mountPoint, "memory.soft_limit_in_bytes")
 	if !info.MemoryReservation {
-		warnings = append(warnings, "Your kernel does not support memory reservation")
+		info.Warnings = append(info.Warnings, "Your kernel does not support memory reservation")
 	}
 	info.OomKillDisable = cgroupEnabled(mountPoint, "memory.oom_control")
 	if !info.OomKillDisable {
-		warnings = append(warnings, "Your kernel does not support oom control")
+		info.Warnings = append(info.Warnings, "Your kernel does not support oom control")
 	}
 	info.MemorySwappiness = cgroupEnabled(mountPoint, "memory.swappiness")
 	if !info.MemorySwappiness {
-		warnings = append(warnings, "Your kernel does not support memory swappiness")
+		info.Warnings = append(info.Warnings, "Your kernel does not support memory swappiness")
 	}
 	info.KernelMemory = cgroupEnabled(mountPoint, "memory.kmem.limit_in_bytes")
 	if !info.KernelMemory {
-		warnings = append(warnings, "Your kernel does not support kernel memory limit")
+		info.Warnings = append(info.Warnings, "Your kernel does not support kernel memory limit")
 	}
 	info.KernelMemoryTCP = cgroupEnabled(mountPoint, "memory.kmem.tcp.limit_in_bytes")
 	if !info.KernelMemoryTCP {
-		warnings = append(warnings, "Your kernel does not support kernel memory TCP limit")
+		info.Warnings = append(info.Warnings, "Your kernel does not support kernel memory TCP limit")
 	}
-
-	return warnings
 }
 
 // applyCPUCgroupInfo adds the cpu cgroup controller information to the info.
-func applyCPUCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
-	var warnings []string
-	mountPoint, ok := cgMounts["cpu"]
+func applyCPUCgroupInfo(info *SysInfo) {
+	mountPoint, ok := info.cgMounts["cpu"]
 	if !ok {
-		warnings = append(warnings, "Unable to find cpu cgroup in mounts")
-		return warnings
+		info.Warnings = append(info.Warnings, "Unable to find cpu cgroup in mounts")
+		return
 	}
 
 	info.CPUShares = cgroupEnabled(mountPoint, "cpu.shares")
 	if !info.CPUShares {
-		warnings = append(warnings, "Your kernel does not support CPU shares")
+		info.Warnings = append(info.Warnings, "Your kernel does not support CPU shares")
 	}
 
 	info.CPUCfs = cgroupEnabled(mountPoint, "cpu.cfs_quota_us")
 	if !info.CPUCfs {
-		warnings = append(warnings, "Your kernel does not support CPU CFS scheduler")
+		info.Warnings = append(info.Warnings, "Your kernel does not support CPU CFS scheduler")
 	}
 
 	info.CPURealtime = cgroupEnabled(mountPoint, "cpu.rt_period_us")
 	if !info.CPURealtime {
-		warnings = append(warnings, "Your kernel does not support CPU realtime scheduler")
+		info.Warnings = append(info.Warnings, "Your kernel does not support CPU realtime scheduler")
 	}
-
-	return warnings
 }
 
 // applyBlkioCgroupInfo adds the blkio cgroup controller information to the info.
-func applyBlkioCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
-	var warnings []string
-	mountPoint, ok := cgMounts["blkio"]
+func applyBlkioCgroupInfo(info *SysInfo) {
+	mountPoint, ok := info.cgMounts["blkio"]
 	if !ok {
-		warnings = append(warnings, "Unable to find blkio cgroup in mounts")
-		return warnings
+		info.Warnings = append(info.Warnings, "Unable to find blkio cgroup in mounts")
+		return
 	}
 
 	info.BlkioWeight = cgroupEnabled(mountPoint, "blkio.weight")
 	if !info.BlkioWeight {
-		warnings = append(warnings, "Your kernel does not support cgroup blkio weight")
+		info.Warnings = append(info.Warnings, "Your kernel does not support cgroup blkio weight")
 	}
 
 	info.BlkioWeightDevice = cgroupEnabled(mountPoint, "blkio.weight_device")
 	if !info.BlkioWeightDevice {
-		warnings = append(warnings, "Your kernel does not support cgroup blkio weight_device")
+		info.Warnings = append(info.Warnings, "Your kernel does not support cgroup blkio weight_device")
 	}
 
 	info.BlkioReadBpsDevice = cgroupEnabled(mountPoint, "blkio.throttle.read_bps_device")
 	if !info.BlkioReadBpsDevice {
-		warnings = append(warnings, "Your kernel does not support cgroup blkio throttle.read_bps_device")
+		info.Warnings = append(info.Warnings, "Your kernel does not support cgroup blkio throttle.read_bps_device")
 	}
 
 	info.BlkioWriteBpsDevice = cgroupEnabled(mountPoint, "blkio.throttle.write_bps_device")
 	if !info.BlkioWriteBpsDevice {
-		warnings = append(warnings, "Your kernel does not support cgroup blkio throttle.write_bps_device")
+		info.Warnings = append(info.Warnings, "Your kernel does not support cgroup blkio throttle.write_bps_device")
 	}
 	info.BlkioReadIOpsDevice = cgroupEnabled(mountPoint, "blkio.throttle.read_iops_device")
 	if !info.BlkioReadIOpsDevice {
-		warnings = append(warnings, "Your kernel does not support cgroup blkio throttle.read_iops_device")
+		info.Warnings = append(info.Warnings, "Your kernel does not support cgroup blkio throttle.read_iops_device")
 	}
 
 	info.BlkioWriteIOpsDevice = cgroupEnabled(mountPoint, "blkio.throttle.write_iops_device")
 	if !info.BlkioWriteIOpsDevice {
-		warnings = append(warnings, "Your kernel does not support cgroup blkio throttle.write_iops_device")
+		info.Warnings = append(info.Warnings, "Your kernel does not support cgroup blkio throttle.write_iops_device")
 	}
-
-	return warnings
 }
 
 // applyCPUSetCgroupInfo adds the cpuset cgroup controller information to the info.
-func applyCPUSetCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
-	var warnings []string
-	mountPoint, ok := cgMounts["cpuset"]
+func applyCPUSetCgroupInfo(info *SysInfo) {
+	mountPoint, ok := info.cgMounts["cpuset"]
 	if !ok {
-		warnings = append(warnings, "Unable to find cpuset cgroup in mounts")
-		return warnings
+		info.Warnings = append(info.Warnings, "Unable to find cpuset cgroup in mounts")
+		return
 	}
 	info.Cpuset = ok
 
@@ -217,66 +196,54 @@ func applyCPUSetCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
 
 	cpus, err := ioutil.ReadFile(path.Join(mountPoint, "cpuset.cpus"))
 	if err != nil {
-		return warnings
+		return
 	}
 	info.Cpus = strings.TrimSpace(string(cpus))
 
 	mems, err := ioutil.ReadFile(path.Join(mountPoint, "cpuset.mems"))
 	if err != nil {
-		return warnings
+		return
 	}
 	info.Mems = strings.TrimSpace(string(mems))
-
-	return warnings
 }
 
 // applyPIDSCgroupInfo adds whether the pids cgroup controller is available to the info.
-func applyPIDSCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
-	var warnings []string
-	_, ok := cgMounts["pids"]
+func applyPIDSCgroupInfo(info *SysInfo) {
+	_, ok := info.cgMounts["pids"]
 	if !ok {
-		warnings = append(warnings, "Unable to find pids cgroup in mounts")
-		return warnings
+		info.Warnings = append(info.Warnings, "Unable to find pids cgroup in mounts")
+		return
 	}
 	info.PidsLimit = true
-	return warnings
 }
 
 // applyDevicesCgroupInfo adds whether the devices cgroup controller is available to the info.
-func applyDevicesCgroupInfo(info *SysInfo, cgMounts map[string]string) []string {
-	var warnings []string
-	_, ok := cgMounts["devices"]
+func applyDevicesCgroupInfo(info *SysInfo) {
+	_, ok := info.cgMounts["devices"]
 	info.CgroupDevicesEnabled = ok
-	return warnings
 }
 
 // applyNetworkingInfo adds networking information to the info.
-func applyNetworkingInfo(info *SysInfo, _ map[string]string) []string {
-	var warnings []string
+func applyNetworkingInfo(info *SysInfo) {
 	info.IPv4ForwardingDisabled = !readProcBool("/proc/sys/net/ipv4/ip_forward")
 	info.BridgeNFCallIPTablesDisabled = !readProcBool("/proc/sys/net/bridge/bridge-nf-call-iptables")
 	info.BridgeNFCallIP6TablesDisabled = !readProcBool("/proc/sys/net/bridge/bridge-nf-call-ip6tables")
-	return warnings
 }
 
 // applyAppArmorInfo adds whether AppArmor is enabled to the info.
-func applyAppArmorInfo(info *SysInfo, _ map[string]string) []string {
-	var warnings []string
+func applyAppArmorInfo(info *SysInfo) {
 	if _, err := os.Stat("/sys/kernel/security/apparmor"); !os.IsNotExist(err) {
 		if _, err := ioutil.ReadFile("/sys/kernel/security/apparmor/profiles"); err == nil {
 			info.AppArmor = true
 		}
 	}
-	return warnings
 }
 
 // applyCgroupNsInfo adds whether cgroupns is enabled to the info.
-func applyCgroupNsInfo(info *SysInfo, _ map[string]string) []string {
-	var warnings []string
+func applyCgroupNsInfo(info *SysInfo) {
 	if _, err := os.Stat("/proc/self/ns/cgroup"); !os.IsNotExist(err) {
 		info.CgroupNamespaces = true
 	}
-	return warnings
 }
 
 var (
@@ -285,8 +252,7 @@ var (
 )
 
 // applySeccompInfo checks if Seccomp is supported, via CONFIG_SECCOMP.
-func applySeccompInfo(info *SysInfo, _ map[string]string) []string {
-	var warnings []string
+func applySeccompInfo(info *SysInfo) {
 	seccompOnce.Do(func() {
 		// Check if Seccomp is supported, via CONFIG_SECCOMP.
 		if err := unix.Prctl(unix.PR_GET_SECCOMP, 0, 0, 0, 0); err != unix.EINVAL {
@@ -297,7 +263,6 @@ func applySeccompInfo(info *SysInfo, _ map[string]string) []string {
 		}
 	})
 	info.Seccomp = seccompEnabled
-	return warnings
 }
 
 func cgroupEnabled(mountPoint, name string) bool {

pkg/sysinfo/sysinfo_linux_test.go

@@ -55,11 +55,7 @@ func TestCgroupEnabled(t *testing.T) {
 }
 
 func TestNew(t *testing.T) {
-	sysInfo := New(false)
-	assert.Assert(t, sysInfo != nil)
-	checkSysInfo(t, sysInfo)
-
-	sysInfo = New(true)
+	sysInfo := New()
 	assert.Assert(t, sysInfo != nil)
 	checkSysInfo(t, sysInfo)
 }
@@ -79,20 +75,20 @@ func checkSysInfo(t *testing.T, sysInfo *SysInfo) {
 func TestNewAppArmorEnabled(t *testing.T) {
 	// Check if AppArmor is supported. then it must be TRUE , else FALSE
 	if _, err := os.Stat("/sys/kernel/security/apparmor"); err != nil {
-		t.Skip("App Armor Must be Enabled")
+		t.Skip("AppArmor Must be Enabled")
 	}
 
-	sysInfo := New(true)
+	sysInfo := New()
 	assert.Assert(t, sysInfo.AppArmor)
 }
 
 func TestNewAppArmorDisabled(t *testing.T) {
 	// Check if AppArmor is supported. then it must be TRUE , else FALSE
 	if _, err := os.Stat("/sys/kernel/security/apparmor"); !os.IsNotExist(err) {
-		t.Skip("App Armor Must be Disabled")
+		t.Skip("AppArmor Must be Disabled")
 	}
 
-	sysInfo := New(true)
+	sysInfo := New()
 	assert.Assert(t, !sysInfo.AppArmor)
 }
 
@@ -102,7 +98,7 @@ func TestNewCgroupNamespacesEnabled(t *testing.T) {
 		t.Skip("cgroup namespaces must be enabled")
 	}
 
-	sysInfo := New(true)
+	sysInfo := New()
 	assert.Assert(t, sysInfo.CgroupNamespaces)
 }
 
@@ -112,7 +108,7 @@ func TestNewCgroupNamespacesDisabled(t *testing.T) {
 		t.Skip("cgroup namespaces must be disabled")
 	}
 
-	sysInfo := New(true)
+	sysInfo := New()
 	assert.Assert(t, !sysInfo.CgroupNamespaces)
 }
 

pkg/sysinfo/sysinfo_other.go

@@ -0,0 +1,8 @@
+// +build !linux
+
+package sysinfo // import "github.com/docker/docker/pkg/sysinfo"
+
+// New returns an empty SysInfo for non linux for now.
+func New(options ...Opt) *SysInfo {
+	return &SysInfo{}
+}

pkg/sysinfo/sysinfo_unix.go

@@ -1,14 +0,0 @@
-// +build !linux,!windows
-
-package sysinfo // import "github.com/docker/docker/pkg/sysinfo"
-
-type opts struct{}
-
-// Opt for New().
-type Opt func(*opts)
-
-// New returns an empty SysInfo for non linux for now.
-func New(quiet bool, options ...Opt) *SysInfo {
-	sysInfo := &SysInfo{}
-	return sysInfo
-}

pkg/sysinfo/sysinfo_windows.go

@@ -1,12 +0,0 @@
-package sysinfo // import "github.com/docker/docker/pkg/sysinfo"
-
-type opts struct{}
-
-// Opt for New().
-type Opt func(*opts)
-
-// New returns an empty SysInfo for windows for now.
-func New(quiet bool, options ...Opt) *SysInfo {
-	sysInfo := &SysInfo{}
-	return sysInfo
-}

runconfig/config.go

@@ -21,7 +21,7 @@ func (r ContainerDecoder) DecodeConfig(src io.Reader) (*container.Config, *conta
 	if r.GetSysInfo != nil {
 		si = r.GetSysInfo()
 	} else {
-		si = sysinfo.New(true)
+		si = sysinfo.New()
 	}
 
 	return decodeContainerConfig(src, si)

runconfig/config_test.go

@@ -47,7 +47,7 @@ func TestDecodeContainerConfig(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		c, h, _, err := decodeContainerConfig(bytes.NewReader(b), sysinfo.New(true))
+		c, h, _, err := decodeContainerConfig(bytes.NewReader(b), sysinfo.New())
 		if err != nil {
 			t.Fatal(fmt.Errorf("Error parsing %s: %v", f, err))
 		}
@@ -131,5 +131,5 @@ func callDecodeContainerConfigIsolation(isolation string) (*container.Config, *c
 	if b, err = json.Marshal(w); err != nil {
 		return nil, nil, nil, fmt.Errorf("Error on marshal %s", err.Error())
 	}
-	return decodeContainerConfig(bytes.NewReader(b), sysinfo.New(true))
+	return decodeContainerConfig(bytes.NewReader(b), sysinfo.New())
 }