Golang cgroups.ParseCgroupFile函數代碼示例

func getCgroupMounts(m *configs.Mount) ([]*configs.Mount, error) {
	mounts, err := cgroups.GetCgroupMounts()
	if err != nil {
		return nil, err
	}

	cgroupPaths, err := cgroups.ParseCgroupFile("/proc/self/cgroup")
	if err != nil {
		return nil, err
	}

	var binds []*configs.Mount

	for _, mm := range mounts {
		dir, err := mm.GetThisCgroupDir(cgroupPaths)
		if err != nil {
			return nil, err
		}
		relDir, err := filepath.Rel(mm.Root, dir)
		if err != nil {
			return nil, err
		}
		binds = append(binds, &configs.Mount{
			Device:           "bind",
			Source:           filepath.Join(mm.Mountpoint, relDir),
			Destination:      filepath.Join(m.Destination, strings.Join(mm.Subsystems, ",")),
			Flags:            syscall.MS_BIND | syscall.MS_REC | m.Flags,
			PropagationFlags: m.PropagationFlags,
		})
	}

	return binds, nil
}

// Gets the (CPU) container the specified pid is in.
func getContainer(pid int) (string, error) {
	cgs, err := cgroups.ParseCgroupFile(fmt.Sprintf("/proc/%d/cgroup", pid))
	if err != nil {
		return "", err
	}

	cg, ok := cgs["cpu"]
	if ok {
		return cg, nil
	}

	return "", cgroups.NewNotFoundError("cpu")
}

// getContainer returns the cgroup associated with the specified pid.
// It enforces a unified hierarchy for memory and cpu cgroups.
// On systemd environments, it uses the name=systemd cgroup for the specified pid.
func getContainer(pid int) (string, error) {
	cgs, err := cgroups.ParseCgroupFile(fmt.Sprintf("/proc/%d/cgroup", pid))
	if err != nil {
		return "", err
	}

	cpu, found := cgs["cpu"]
	if !found {
		return "", cgroups.NewNotFoundError("cpu")
	}
	memory, found := cgs["memory"]
	if !found {
		return "", cgroups.NewNotFoundError("memory")
	}

	// since we use this container for accounting, we need to ensure its a unified hierarchy.
	if cpu != memory {
		return "", fmt.Errorf("cpu and memory cgroup hierarchy not unified.  cpu: %s, memory: %s", cpu, memory)
	}

	// on systemd, every pid is in a unified cgroup hierarchy (name=systemd as seen in systemd-cgls)
	// cpu and memory accounting is off by default, users may choose to enable it per unit or globally.
	// users could enable CPU and memory accounting globally via /etc/systemd/system.conf (DefaultCPUAccounting=true DefaultMemoryAccounting=true).
	// users could also enable CPU and memory accounting per unit via CPUAccounting=true and MemoryAccounting=true
	// we only warn if accounting is not enabled for CPU or memory so as to not break local development flows where kubelet is launched in a terminal.
	// for example, the cgroup for the user session will be something like /user.slice/user-X.slice/session-X.scope, but the cpu and memory
	// cgroup will be the closest ancestor where accounting is performed (most likely /) on systems that launch docker containers.
	// as a result, on those systems, you will not get cpu or memory accounting statistics for kubelet.
	// in addition, you would not get memory or cpu accounting for the runtime unless accounting was enabled on its unit (or globally).
	if systemd, found := cgs["name=systemd"]; found {
		if systemd != cpu {
			glog.Warningf("CPUAccounting not enabled for pid: %d", pid)
		}
		if systemd != memory {
			glog.Warningf("MemoryAccounting not enabled for pid: %d", pid)
		}
		return systemd, nil
	}

	return cpu, nil
}

func (c *linuxContainer) criuApplyCgroups(pid int, req *criurpc.CriuReq) error {
	if err := c.cgroupManager.Apply(pid); err != nil {
		return err
	}

	path := fmt.Sprintf("/proc/%d/cgroup", pid)
	cgroupsPaths, err := cgroups.ParseCgroupFile(path)
	if err != nil {
		return err
	}

	for c, p := range cgroupsPaths {
		cgroupRoot := &criurpc.CgroupRoot{
			Ctrl: proto.String(c),
			Path: proto.String(p),
		}
		req.Opts.CgRoot = append(req.Opts.CgRoot, cgroupRoot)
	}

	return nil
}