Golang cgroups.FindCgroupMountpoint函數代碼示例

func New(quiet bool) *SysInfo {
	sysInfo := &SysInfo{}
	if cgroupMemoryMountpoint, err := cgroups.FindCgroupMountpoint("memory"); err != nil {
		if !quiet {
			log.Printf("WARNING: %s\n", 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 {
			log.Printf("WARNING: 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 {
			log.Printf("WARNING: Your kernel does not support cgroup swap limit.")
		}
	}

	content, err3 := ioutil.ReadFile("/proc/sys/net/ipv4/ip_forward")
	sysInfo.IPv4ForwardingDisabled = err3 != nil || len(content) == 0 || content[0] != '1'
	if sysInfo.IPv4ForwardingDisabled && !quiet {
		log.Printf("WARNING: IPv4 forwarding is disabled.")
	}

	// Check if AppArmor seems to be enabled on this system.
	if _, err := os.Stat("/sys/kernel/security/apparmor"); os.IsNotExist(err) {
		sysInfo.AppArmor = false
	} else {
		sysInfo.AppArmor = true
	}
	return sysInfo
}

// TODO: this can be improved with our driver
// there has to be a better way to do this
func (d *driver) GetPidsForContainer(id string) ([]int, error) {
	pids := []int{}

	subsystem := "devices"
	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) {
		filename = filepath.Join(cgroupRoot, cgroupDir, "docker", 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 GetStats(c *cgroups.Cgroup, subsystem string, pid int) (map[string]float64, error) {
	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)
	}

	d := &data{
		root:   cgroupRoot,
		cgroup: cgroup,
		c:      c,
		pid:    pid,
	}
	sys, exists := subsystems[subsystem]
	if !exists {
		return nil, fmt.Errorf("subsystem %s does not exist", subsystem)
	}
	return sys.Stats(d)
}

func (d *driver) GetPidsForContainer(id string) ([]int, error) {
	pids := []int{}

	// memory is chosen randomly, any cgroup used by docker works
	subsystem := "memory"

	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 Apply(c *cgroups.Cgroup, pid int) (cgroups.ActiveCgroup, error) {
	// We have two implementation of cgroups support, one is based on
	// systemd and the dbus api, and one is based on raw cgroup fs operations
	// following the pre-single-writer model docs at:
	// http://www.freedesktop.org/wiki/Software/systemd/PaxControlGroups/
	//
	// 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)
	}

	d := &data{
		root:   cgroupRoot,
		cgroup: cgroup,
		c:      c,
		pid:    pid,
	}
	for _, sys := range subsystems {
		if err := sys.Set(d); err != nil {
			d.Cleanup()
			return nil, err
		}
	}
	return d, nil
}

func Apply(c *cgroups.Cgroup, pid int) (cgroups.ActiveCgroup, error) {
	var (
		unitName   = c.Parent + "-" + c.Name + ".scope"
		slice      = "system.slice"
		properties []systemd1.Property
	)

	for _, v := range c.UnitProperties {
		switch v[0] {
		case "Slice":
			slice = v[1]
		default:
			return nil, fmt.Errorf("Unknown unit propery %s", v[0])
		}
	}

	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)})},
	)

	if !c.DeviceAccess {
		properties = append(properties,
			systemd1.Property{"DevicePolicy", dbus.MakeVariant("strict")},
			systemd1.Property{"DeviceAllow", dbus.MakeVariant([]DeviceAllow{
				{"/dev/null", "rwm"},
				{"/dev/zero", "rwm"},
				{"/dev/full", "rwm"},
				{"/dev/random", "rwm"},
				{"/dev/urandom", "rwm"},
				{"/dev/tty", "rwm"},
				{"/dev/console", "rwm"},
				{"/dev/tty0", "rwm"},
				{"/dev/tty1", "rwm"},
				{"/dev/pts/ptmx", "rwm"},
				// There is no way to add /dev/pts/* here atm, so we hack this manually below
				// /dev/pts/* (how to add this?)
				// Same with tuntap, which doesn't exist as a node most of the time
			})})
	}

	// Always enable accounting, this gets us the same behaviour as the raw 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)})

	if c.Memory != 0 {
		properties = append(properties,
			systemd1.Property{"MemoryLimit", dbus.MakeVariant(uint64(c.Memory))})
	}
	if c.MemoryReservation != 0 {
		properties = append(properties,
			systemd1.Property{"MemorySoftLimit", dbus.MakeVariant(uint64(c.MemoryReservation))})
	}
	// TODO: 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.DeviceAccess {
		mountpoint, err := cgroups.FindCgroupMountpoint("devices")
		if err != nil {
			return nil, err
		}

		path := filepath.Join(mountpoint, cgroup)

		// /dev/pts/*
		if err := ioutil.WriteFile(filepath.Join(path, "devices.allow"), []byte("c 136:* rwm"), 0700); err != nil {
			return nil, err
		}
		// tuntap
		if err := ioutil.WriteFile(filepath.Join(path, "devices.allow"), []byte("c 10:200 rwm"), 0700); err != nil {
			return nil, err
		}
	}
	return &systemdCgroup{}, nil
}

func Apply(c *cgroups.Cgroup, pid int) (cgroups.ActiveCgroup, error) {
	var (
		unitName   = c.Parent + "-" + c.Name + ".scope"
		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)})},
	)

	if !c.DeviceAccess {
		properties = append(properties,
			systemd1.Property{"DevicePolicy", dbus.MakeVariant("strict")},
			systemd1.Property{"DeviceAllow", dbus.MakeVariant([]DeviceAllow{
				{"/dev/null", "rwm"},
				{"/dev/zero", "rwm"},
				{"/dev/full", "rwm"},
				{"/dev/random", "rwm"},
				{"/dev/urandom", "rwm"},
				{"/dev/tty", "rwm"},
				{"/dev/console", "rwm"},
				{"/dev/tty0", "rwm"},
				{"/dev/tty1", "rwm"},
				{"/dev/pts/ptmx", "rwm"},
				// There is no way to add /dev/pts/* here atm, so we hack this manually below
				// /dev/pts/* (how to add this?)
				// Same with tuntap, which doesn't exist as a node most of the time
			})})
	}

	// 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.DeviceAccess {
		mountpoint, err := cgroups.FindCgroupMountpoint("devices")
		if err != nil {
			return nil, err
		}

		path := filepath.Join(mountpoint, cgroup)

		// /dev/pts/*
		if err := ioutil.WriteFile(filepath.Join(path, "devices.allow"), []byte("c 136:* rwm"), 0700); err != nil {
//.........這裏部分代碼省略.........