// New returns a new SysInfo, using the filesystem to detect which features the kernel supports.
func New(quiet bool) *SysInfo {
sysInfo := &SysInfo{}
if cgroupMemoryMountpoint, err := cgroups.FindCgroupMountpoint("memory"); err != nil {
if !quiet {
logrus.Warnf("Your kernel does not support cgroup memory limit: %v", err)
}
} else {
// If memory cgroup is mounted, MemoryLimit is always enabled.
sysInfo.MemoryLimit = true
_, err1 := ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.memsw.limit_in_bytes"))
sysInfo.SwapLimit = err1 == nil
if !sysInfo.SwapLimit && !quiet {
logrus.Warn("Your kernel does not support swap memory limit.")
}
_, err = ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.oom_control"))
sysInfo.OomKillDisable = err == nil
if !sysInfo.OomKillDisable && !quiet {
logrus.Warnf("Your kernel does not support oom control.")
}
}
if cgroupCpuMountpoint, err := cgroups.FindCgroupMountpoint("cpu"); err != nil {
if !quiet {
logrus.Warnf("%v", err)
}
} else {
_, err1 := ioutil.ReadFile(path.Join(cgroupCpuMountpoint, "cpu.cfs_quota_us"))
sysInfo.CpuCfsQuota = err1 == nil
if !sysInfo.CpuCfsQuota && !quiet {
logrus.Warn("Your kernel does not support cgroup cfs quotas")
}
}
// Checek if ipv4_forward is disabled.
if data, err := ioutil.ReadFile("/proc/sys/net/ipv4/ip_forward"); os.IsNotExist(err) {
sysInfo.IPv4ForwardingDisabled = true
} else {
if enabled, _ := strconv.Atoi(strings.TrimSpace(string(data))); enabled == 0 {
sysInfo.IPv4ForwardingDisabled = true
} else {
sysInfo.IPv4ForwardingDisabled = false
}
}
// Check if AppArmor is supported.
if _, err := os.Stat("/sys/kernel/security/apparmor"); os.IsNotExist(err) {
sysInfo.AppArmor = false
} else {
sysInfo.AppArmor = true
}
// Check if Devices cgroup is mounted, it is hard requirement for container security.
if _, err := cgroups.FindCgroupMountpoint("devices"); err != nil {
logrus.Fatalf("Error mounting devices cgroup: %v", err)
}
return sysInfo
}
// New returns a new SysInfo, using the filesystem to detect which features the kernel supports.
func New(quiet bool) *SysInfo {
sysInfo := &SysInfo{}
if cgroupMemoryMountpoint, err := cgroups.FindCgroupMountpoint("memory"); err != nil {
if !quiet {
logrus.Warnf("%s", err)
}
} else {
_, err1 := ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.limit_in_bytes"))
_, err2 := ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.soft_limit_in_bytes"))
sysInfo.MemoryLimit = err1 == nil && err2 == nil
if !sysInfo.MemoryLimit && !quiet {
logrus.Warnf("Your kernel does not support cgroup memory limit.")
}
_, err = ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.memsw.limit_in_bytes"))
sysInfo.SwapLimit = err == nil
if !sysInfo.SwapLimit && !quiet {
logrus.Warnf("Your kernel does not support cgroup swap limit.")
}
}
// Check if AppArmor is supported.
if _, err := os.Stat("/sys/kernel/security/apparmor"); os.IsNotExist(err) {
sysInfo.AppArmor = false
} else {
sysInfo.AppArmor = true
}
return sysInfo
}
func getPath(id, driver, subsystem string) (string, error) {
cgroupRoot, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return "", err
}
cgroupRoot = filepath.Dir(cgroupRoot)
if _, err := os.Stat(cgroupRoot); err != nil {
return "", fmt.Errorf("cgroups fs not found")
}
group, err := findGroup(subsystem)
if err != nil {
return "", err
}
initPath, err := cgroups.GetInitCgroupDir(group)
if err != nil {
return "", err
}
path := path.Join(cgroupRoot, group, initPath, driver, id, subsystem)
if _, err := os.Stat(path); err != nil {
return "", fmt.Errorf("%s not found", path)
}
return path, nil
}
// TODO(vmarmol): Report error here, we'll probably need to wait for the new API.
func init() {
// we can pick any subsystem to find the root
cpuRoot, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return
}
cgroupRoot = filepath.Dir(cpuRoot)
if _, err := os.Stat(cgroupRoot); err != nil {
return
}
}
func findCgroupRootAndDir(subsystem string) (string, string, error) {
cgroupRoot, err := cgroups.FindCgroupMountpoint(subsystem)
if err != nil {
return "", "", err
}
cgroupDir, err := cgroups.GetThisCgroupDir(subsystem)
if err != nil {
return "", "", err
}
return cgroupRoot, cgroupDir, nil
}
func init() {
useSystemd = systemd.UseSystemd()
if !useSystemd {
// Second attempt at checking for systemd, check for a "name=systemd" cgroup.
mnt, err := cgroups.FindCgroupMountpoint("cpu")
if err == nil {
// systemd presence does not mean systemd controls cgroups.
// If system.slice cgroup exists, then systemd is taking control.
// This breaks if user creates system.slice manually :)
useSystemd = utils.FileExists(mnt + "/system.slice")
}
}
}
func getFreezerPath(c *cgroups.Cgroup) (string, error) {
mountpoint, err := cgroups.FindCgroupMountpoint("freezer")
if err != nil {
return "", err
}
initPath, err := cgroups.GetInitCgroupDir("freezer")
if err != nil {
return "", err
}
return filepath.Join(mountpoint, initPath, fmt.Sprintf("%s-%s", c.Parent, c.Name)), nil
}
func GetPids(c *cgroups.Cgroup) ([]int, error) {
unitName := getUnitName(c)
mountpoint, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return nil, err
}
props, err := theConn.GetUnitTypeProperties(unitName, getIfaceForUnit(unitName))
if err != nil {
return nil, err
}
cgroup := props["ControlGroup"].(string)
return cgroups.ReadProcsFile(filepath.Join(mountpoint, cgroup))
}
func validateCgroupMounts() (string, string) {
const recommendedMount = "/sys/fs/cgroup"
desc := fmt.Sprintf("\tAny cgroup mount point that is detectible and accessible is supported. %s is recommended as a standard location.\n", recommendedMount)
mnt, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
out := "Could not locate cgroup mount point.\n"
out += desc
return Unknown, out
}
mnt = path.Dir(mnt)
if !utils.FileExists(mnt) {
out := fmt.Sprintf("Cgroup mount directory %s inaccessible.\n", mnt)
out += desc
return Unsupported, out
}
mounts, err := ioutil.ReadDir(mnt)
if err != nil {
out := fmt.Sprintf("Could not read cgroup mount directory %s.\n", mnt)
out += desc
return Unsupported, out
}
mountNames := "\tCgroup mount directories: "
for _, mount := range mounts {
mountNames += mount.Name() + " "
}
mountNames += "\n"
out := fmt.Sprintf("Cgroups are mounted at %s.\n", mnt)
out += mountNames
out += desc
info, err := ioutil.ReadFile("/proc/mounts")
if err != nil {
out := fmt.Sprintf("Could not read /proc/mounts.\n")
out += desc
return Unsupported, out
}
out += "\tCgroup mounts:\n"
for _, line := range strings.Split(string(info), "\n") {
if strings.Contains(line, " cgroup ") {
out += "\t" + line + "\n"
}
}
if mnt == recommendedMount {
return Recommended, out
}
return Supported, out
}
func getSubsystemPath(c *configs.Cgroup, subsystem string) (string, error) {
mountpoint, err := cgroups.FindCgroupMountpoint(subsystem)
if err != nil {
return "", err
}
initPath, err := cgroups.GetInitCgroupDir(subsystem)
if err != nil {
return "", err
}
slice := "system.slice"
if c.Slice != "" {
slice = c.Slice
}
return filepath.Join(mountpoint, initPath, slice, getUnitName(c)), nil
}
// New returns a new SysInfo, using the filesystem to detect which features the kernel supports.
func New(quiet bool) *SysInfo {
sysInfo := &SysInfo{}
sysInfo.cgroupMemInfo = checkCgroupMem(quiet)
sysInfo.cgroupCpuInfo = checkCgroupCpu(quiet)
_, err := cgroups.FindCgroupMountpoint("devices")
sysInfo.CgroupDevicesEnabled = err == nil
sysInfo.IPv4ForwardingDisabled = !readProcBool("/proc/sys/net/ipv4/ip_forward")
sysInfo.BridgeNfCallIptablesDisabled = !readProcBool("/proc/sys/net/bridge/bridge-nf-call-iptables")
sysInfo.BridgeNfCallIp6tablesDisabled = !readProcBool("/proc/sys/net/bridge/bridge-nf-call-ip6tables")
// Check if AppArmor is supported.
if _, err := os.Stat("/sys/kernel/security/apparmor"); !os.IsNotExist(err) {
sysInfo.AppArmor = true
}
return sysInfo
}
func (raw *data) path(subsystem string) (string, error) {
_, err := cgroups.FindCgroupMountpoint(subsystem)
// If we didn't mount the subsystem, there is no point we make the path.
if err != nil {
return "", err
}
// If the cgroup name/path is absolute do not look relative to the cgroup of the init process.
if filepath.IsAbs(raw.cgroup) {
return filepath.Join(raw.root, subsystem, raw.cgroup), nil
}
parent, err := raw.parent(subsystem)
if err != nil {
return "", err
}
return filepath.Join(parent, raw.cgroup), nil
}
func UseSystemd() bool {
check.Do(func() {
useSystemd = false
// Check for system.slice in systemd and cpu cgroup.
for _, cgroupType := range []string{"name=systemd", "cpu"} {
mnt, err := cgroups.FindCgroupMountpoint(cgroupType)
if err == nil {
// systemd presence does not mean systemd controls cgroups.
// If system.slice cgroup exists, then systemd is taking control.
// This breaks if user creates system.slice manually :)
if utils.FileExists(path.Join(mnt, "system.slice")) {
useSystemd = true
break
}
}
}
})
return useSystemd
}
func checkCgroupCpu(quiet bool) *cgroupCpuInfo {
info := &cgroupCpuInfo{}
mountPoint, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
if !quiet {
logrus.Warn(err)
}
return info
}
info.CpuCfsPeriod = cgroupEnabled(mountPoint, "cpu.cfs_period_us")
if !quiet && !info.CpuCfsPeriod {
logrus.Warn("Your kernel does not support cgroup cfs period")
}
info.CpuCfsQuota = cgroupEnabled(mountPoint, "cpu.cfs_quota_us")
if !quiet && !info.CpuCfsQuota {
logrus.Warn("Your kernel does not support cgroup cfs quotas")
}
return info
}
// Gets the cgroupRoot.
func getCgroupRoot() (string, error) {
cgroupRootLock.Lock()
defer cgroupRootLock.Unlock()
if cgroupRoot != "" {
return cgroupRoot, nil
}
// we can pick any subsystem to find the root
cpuRoot, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return "", err
}
root := filepath.Dir(cpuRoot)
if _, err := os.Stat(root); err != nil {
return "", err
}
cgroupRoot = root
return cgroupRoot, nil
}
func checkCgroupMem(quiet bool) *cgroupMemInfo {
info := &cgroupMemInfo{}
mountPoint, err := cgroups.FindCgroupMountpoint("memory")
if err != nil {
if !quiet {
logrus.Warnf("Your kernel does not support cgroup memory limit: %v", err)
}
return info
}
info.MemoryLimit = true
info.SwapLimit = cgroupEnabled(mountPoint, "memory.memsw.limit_in_bytes")
if !quiet && !info.SwapLimit {
logrus.Warn("Your kernel does not support swap memory limit.")
}
info.OomKillDisable = cgroupEnabled(mountPoint, "memory.oom_control")
if !quiet && !info.OomKillDisable {
logrus.Warnf("Your kernel does not support oom control.")
}
return info
}
func (d *driver) GetPidsForContainer(id string) ([]int, error) {
pids := []int{}
// cpu is chosen because it is the only non optional subsystem in cgroups
subsystem := "cpu"
cgroupRoot, err := cgroups.FindCgroupMountpoint(subsystem)
if err != nil {
return pids, err
}
cgroupDir, err := cgroups.GetThisCgroupDir(subsystem)
if err != nil {
return pids, err
}
filename := filepath.Join(cgroupRoot, cgroupDir, id, "tasks")
if _, err := os.Stat(filename); os.IsNotExist(err) {
// With more recent lxc versions use, cgroup will be in lxc/
filename = filepath.Join(cgroupRoot, cgroupDir, "lxc", id, "tasks")
}
output, err := ioutil.ReadFile(filename)
if err != nil {
return pids, err
}
for _, p := range strings.Split(string(output), "\n") {
if len(p) == 0 {
continue
}
pid, err := strconv.Atoi(p)
if err != nil {
return pids, fmt.Errorf("Invalid pid '%s': %s", p, err)
}
pids = append(pids, pid)
}
return pids, nil
}
func validateMemoryAccounting(available_cgroups map[string]int) string {
ok, _ := areCgroupsPresent(available_cgroups, []string{"memory"})
if !ok {
return "\tHierarchical memory accounting status unknown: memory cgroup not enabled.\n"
}
mnt, err := cgroups.FindCgroupMountpoint("memory")
if err != nil {
return "\tHierarchical memory accounting status unknown: memory cgroup not mounted.\n"
}
hier, err := ioutil.ReadFile(path.Join(mnt, "memory.use_hierarchy"))
if err != nil {
return "\tHierarchical memory accounting status unknown: hierarchy interface unavailable.\n"
}
var enabled int
n, err := fmt.Sscanf(string(hier), "%d", &enabled)
if err != nil || n != 1 {
return "\tHierarchical memory accounting status unknown: hierarchy interface unreadable.\n"
}
if enabled == 1 {
return "\tHierarchical memory accounting enabled. Reported memory usage includes memory used by child containers.\n"
}
return "\tHierarchical memory accounting disabled. Memory usage does not include usage from child containers.\n"
}
func getCgroupData(c *cgroups.Cgroup, pid int) (*data, error) {
// we can pick any subsystem to find the root
cgroupRoot, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return nil, err
}
cgroupRoot = filepath.Dir(cgroupRoot)
if _, err := os.Stat(cgroupRoot); err != nil {
return nil, fmt.Errorf("cgroups fs not found")
}
cgroup := c.Name
if c.Parent != "" {
cgroup = filepath.Join(c.Parent, cgroup)
}
return &data{
root: cgroupRoot,
cgroup: cgroup,
c: c,
pid: pid,
}, nil
}
"Test requires underlying root filesystem not be backed by overlay.",
}
IPv6 = TestRequirement{
func() bool {
cmd := exec.Command("test", "-f", "/proc/net/if_inet6")
if err := cmd.Run(); err != nil {
return true
}
return false
},
"Test requires support for IPv6",
}
OomControl = TestRequirement{
func() bool {
cgroupMemoryMountpoint, err := cgroups.FindCgroupMountpoint("memory")
if err != nil {
return false
}
if _, err := ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.memsw.limit_in_bytes")); err != nil {
return false
}
if _, err = ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.oom_control")); err != nil {
return false
}
return true
},
"Test requires Oom control enabled.",
}
},
"Test requires the native (libcontainer) exec driver.",
}
NotOverlay = TestRequirement{
func() bool {
cmd := exec.Command("grep", "^overlay / overlay", "/proc/mounts")
if err := cmd.Run(); err != nil {
return true
}
return false
},
"Test requires underlying root filesystem not be backed by overlay.",
}
CpuCfsPeriod = TestRequirement{
func() bool {
cgroupCpuMountpoint, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return false
}
if _, err := ioutil.ReadFile(path.Join(cgroupCpuMountpoint, "cpu.cfs_period_us")); err != nil {
return false
}
return true
},
"Test requires an environment that supports cgroup cfs period.",
}
CpuCfsQuota = TestRequirement{
func() bool {
cgroupCpuMountpoint, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return false
// +build !windows
package main
import (
"io/ioutil"
"path"
"github.com/docker/libcontainer/cgroups"
)
var (
CpuCfsPeriod = TestRequirement{
func() bool {
cgroupCpuMountpoint, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return false
}
if _, err := ioutil.ReadFile(path.Join(cgroupCpuMountpoint, "cpu.cfs_period_us")); err != nil {
return false
}
return true
},
"Test requires an environment that supports cgroup cfs period.",
}
CpuCfsQuota = TestRequirement{
func() bool {
cgroupCpuMountpoint, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return false
}
func Apply(c *cgroups.Cgroup, pid int) (cgroups.ActiveCgroup, error) {
var (
unitName = getUnitName(c)
slice = "system.slice"
properties []systemd1.Property
cpuArgs []cgroupArg
cpusetArgs []cgroupArg
memoryArgs []cgroupArg
res systemdCgroup
)
// First set up things not supported by systemd
// -1 disables memorySwap
if c.MemorySwap >= 0 && (c.Memory != 0 || c.MemorySwap > 0) {
memorySwap := c.MemorySwap
if memorySwap == 0 {
// By default, MemorySwap is set to twice the size of RAM.
memorySwap = c.Memory * 2
}
memoryArgs = append(memoryArgs, cgroupArg{"memory.memsw.limit_in_bytes", strconv.FormatInt(memorySwap, 10)})
}
if c.CpusetCpus != "" {
cpusetArgs = append(cpusetArgs, cgroupArg{"cpuset.cpus", c.CpusetCpus})
}
if c.Slice != "" {
slice = c.Slice
}
properties = append(properties,
systemd1.Property{"Slice", dbus.MakeVariant(slice)},
systemd1.Property{"Description", dbus.MakeVariant("docker container " + c.Name)},
systemd1.Property{"PIDs", dbus.MakeVariant([]uint32{uint32(pid)})},
)
// Always enable accounting, this gets us the same behaviour as the fs implementation,
// plus the kernel has some problems with joining the memory cgroup at a later time.
properties = append(properties,
systemd1.Property{"MemoryAccounting", dbus.MakeVariant(true)},
systemd1.Property{"CPUAccounting", dbus.MakeVariant(true)},
systemd1.Property{"BlockIOAccounting", dbus.MakeVariant(true)})
if c.Memory != 0 {
properties = append(properties,
systemd1.Property{"MemoryLimit", dbus.MakeVariant(uint64(c.Memory))})
}
// TODO: MemoryReservation and MemorySwap not available in systemd
if c.CpuShares != 0 {
properties = append(properties,
systemd1.Property{"CPUShares", dbus.MakeVariant(uint64(c.CpuShares))})
}
if _, err := theConn.StartTransientUnit(unitName, "replace", properties...); err != nil {
return nil, err
}
// To work around the lack of /dev/pts/* support above we need to manually add these
// so, ask systemd for the cgroup used
props, err := theConn.GetUnitTypeProperties(unitName, getIfaceForUnit(unitName))
if err != nil {
return nil, err
}
cgroup := props["ControlGroup"].(string)
if !c.AllowAllDevices {
// Atm we can't use the systemd device support because of two missing things:
// * Support for wildcards to allow mknod on any device
// * Support for wildcards to allow /dev/pts support
//
// The second is available in more recent systemd as "char-pts", but not in e.g. v208 which is
// in wide use. When both these are availalable we will be able to switch, but need to keep the old
// implementation for backwards compat.
//
// Note: we can't use systemd to set up the initial limits, and then change the cgroup
// because systemd will re-write the device settings if it needs to re-apply the cgroup context.
// This happens at least for v208 when any sibling unit is started.
mountpoint, err := cgroups.FindCgroupMountpoint("devices")
if err != nil {
return nil, err
}
initPath, err := cgroups.GetInitCgroupDir("devices")
if err != nil {
return nil, err
}
dir := filepath.Join(mountpoint, initPath, c.Parent, c.Name)
res.cleanupDirs = append(res.cleanupDirs, dir)
if err := os.MkdirAll(dir, 0755); err != nil && !os.IsExist(err) {
return nil, err
}
if err := ioutil.WriteFile(filepath.Join(dir, "cgroup.procs"), []byte(strconv.Itoa(pid)), 0700); err != nil {
return nil, err
}
if err := writeFile(dir, "devices.deny", "a"); err != nil {
return nil, err
}
for _, dev := range c.AllowedDevices {
if err := writeFile(dir, "devices.allow", dev.GetCgroupAllowString()); err != nil {
return nil, err
}
}
}
if len(cpuArgs) != 0 {
mountpoint, err := cgroups.FindCgroupMountpoint("cpu")
if err != nil {
return nil, err
}
path := filepath.Join(mountpoint, cgroup)
for _, arg := range cpuArgs {
if err := ioutil.WriteFile(filepath.Join(path, arg.File), []byte(arg.Value), 0700); err != nil {
return nil, err
}
}
}
if len(memoryArgs) != 0 {
mountpoint, err := cgroups.FindCgroupMountpoint("memory")
if err != nil {
return nil, err
}
path := filepath.Join(mountpoint, cgroup)
for _, arg := range memoryArgs {
if err := ioutil.WriteFile(filepath.Join(path, arg.File), []byte(arg.Value), 0700); err != nil {
return nil, err
}
}
}
// we need to manually join the freezer cgroup in systemd because it does not currently support it
// via the dbus api
freezerPath, err := joinFreezer(c, pid)
if err != nil {
return nil, err
}
res.cleanupDirs = append(res.cleanupDirs, freezerPath)
if len(cpusetArgs) != 0 {
// systemd does not atm set up the cpuset controller, so we must manually
// join it. Additionally that is a very finicky controller where each
// level must have a full setup as the default for a new directory is "no cpus",
// so we avoid using any hierarchies here, creating a toplevel directory.
mountpoint, err := cgroups.FindCgroupMountpoint("cpuset")
if err != nil {
return nil, err
}
initPath, err := cgroups.GetInitCgroupDir("cpuset")
if err != nil {
return nil, err
}
var (
foundCpus bool
foundMems bool
rootPath = filepath.Join(mountpoint, initPath)
path = filepath.Join(mountpoint, initPath, c.Parent+"-"+c.Name)
)
res.cleanupDirs = append(res.cleanupDirs, path)
if err := os.MkdirAll(path, 0755); err != nil && !os.IsExist(err) {
return nil, err
}
for _, arg := range cpusetArgs {
if arg.File == "cpuset.cpus" {
foundCpus = true
}
if arg.File == "cpuset.mems" {
foundMems = true
}
if err := ioutil.WriteFile(filepath.Join(path, arg.File), []byte(arg.Value), 0700); err != nil {
return nil, err
}
}
// These are required, if not specified inherit from parent
if !foundCpus {
s, err := ioutil.ReadFile(filepath.Join(rootPath, "cpuset.cpus"))
if err != nil {
return nil, err
}
if err := ioutil.WriteFile(filepath.Join(path, "cpuset.cpus"), s, 0700); err != nil {
return nil, err
}
}
// These are required, if not specified inherit from parent
if !foundMems {
s, err := ioutil.ReadFile(filepath.Join(rootPath, "cpuset.mems"))
if err != nil {
return nil, err
}
if err := ioutil.WriteFile(filepath.Join(path, "cpuset.mems"), s, 0700); err != nil {
return nil, err
}
}
if err := ioutil.WriteFile(filepath.Join(path, "cgroup.procs"), []byte(strconv.Itoa(pid)), 0700); err != nil {
return nil, err
}
}
return &res, nil
}
