runtime: Move the resourcecontrol package one layer up

And try to reduce the number of virtcontainers packages, step by step.

Signed-off-by: Samuel Ortiz <s.ortiz@apple.com>

src/runtime/pkg/resourcecontrol/cgroups.go

@@ -0,0 +1,332 @@
+// +build linux
+//
+// Copyright (c) 2021-2022 Apple Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package resourcecontrol
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/containerd/cgroups"
+	v1 "github.com/containerd/cgroups/stats/v1"
+	"github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/sirupsen/logrus"
+)
+
+// prepend a kata specific string to oci cgroup path to
+// form a different cgroup path, thus cAdvisor couldn't
+// find kata containers cgroup path on host to prevent it
+// from grabbing the stats data.
+const CgroupKataPrefix = "kata"
+
+func RenameCgroupPath(path string) (string, error) {
+	if path == "" {
+		path = DefaultResourceControllerID
+	}
+
+	cgroupPathDir := filepath.Dir(path)
+	cgroupPathName := fmt.Sprintf("%s_%s", CgroupKataPrefix, filepath.Base(path))
+	return filepath.Join(cgroupPathDir, cgroupPathName), nil
+
+}
+
+type LinuxCgroup struct {
+	cgroup  cgroups.Cgroup
+	path    string
+	cpusets *specs.LinuxCPU
+	devices []specs.LinuxDeviceCgroup
+
+	sync.Mutex
+}
+
+func sandboxDevices() []specs.LinuxDeviceCgroup {
+	devices := []specs.LinuxDeviceCgroup{}
+
+	defaultDevices := []string{
+		"/dev/null",
+		"/dev/random",
+		"/dev/full",
+		"/dev/tty",
+		"/dev/zero",
+		"/dev/urandom",
+		"/dev/console",
+	}
+
+	// Processes running in a device-cgroup are constrained, they have acccess
+	// only to the devices listed in the devices.list file.
+	// In order to run Virtual Machines and create virtqueues, hypervisors
+	// need access to certain character devices in the host, like kvm and vhost-net.
+	hypervisorDevices := []string{
+		"/dev/kvm",         // To run virtual machines
+		"/dev/vhost-net",   // To create virtqueues
+		"/dev/vfio/vfio",   // To access VFIO devices
+		"/dev/vhost-vsock", // To interact with vsock if
+	}
+
+	defaultDevices = append(defaultDevices, hypervisorDevices...)
+
+	for _, device := range defaultDevices {
+		ldevice, err := DeviceToLinuxDevice(device)
+		if err != nil {
+			controllerLogger.WithField("source", "cgroups").Warnf("Could not add %s to the devices cgroup", device)
+			continue
+		}
+		devices = append(devices, ldevice)
+	}
+
+	wildcardMajor := int64(-1)
+	wildcardMinor := int64(-1)
+	ptsMajor := int64(136)
+	tunMajor := int64(10)
+	tunMinor := int64(200)
+
+	wildcardDevices := []specs.LinuxDeviceCgroup{
+		// allow mknod for any device
+		{
+			Allow:  true,
+			Type:   "c",
+			Major:  &wildcardMajor,
+			Minor:  &wildcardMinor,
+			Access: "m",
+		},
+		{
+			Allow:  true,
+			Type:   "b",
+			Major:  &wildcardMajor,
+			Minor:  &wildcardMinor,
+			Access: "m",
+		},
+		// /dev/pts/ - pts namespaces are "coming soon"
+		{
+			Allow:  true,
+			Type:   "c",
+			Major:  &ptsMajor,
+			Minor:  &wildcardMinor,
+			Access: "rwm",
+		},
+		// tuntap
+		{
+			Allow:  true,
+			Type:   "c",
+			Major:  &tunMajor,
+			Minor:  &tunMinor,
+			Access: "rwm",
+		},
+	}
+
+	devices = append(devices, wildcardDevices...)
+
+	return devices
+}
+
+func NewResourceController(path string, resources *specs.LinuxResources) (ResourceController, error) {
+	var err error
+
+	cgroupPath, err := ValidCgroupPath(path, IsSystemdCgroup(path))
+	if err != nil {
+		return nil, err
+	}
+
+	cgroup, err := cgroups.New(cgroups.V1, cgroups.StaticPath(cgroupPath), resources)
+	if err != nil {
+		return nil, err
+	}
+
+	return &LinuxCgroup{
+		path:    cgroupPath,
+		devices: resources.Devices,
+		cpusets: resources.CPU,
+		cgroup:  cgroup,
+	}, nil
+}
+
+func NewSandboxResourceController(path string, resources *specs.LinuxResources, sandboxCgroupOnly bool) (ResourceController, error) {
+	var cgroup cgroups.Cgroup
+	sandboxResources := *resources
+	sandboxResources.Devices = append(sandboxResources.Devices, sandboxDevices()...)
+
+	// Currently we know to handle systemd cgroup path only when it's the only cgroup (no overhead group), hence,
+	// if sandboxCgroupOnly is not true we treat it as cgroupfs path as it used to be, although it may be incorrect
+	if !IsSystemdCgroup(path) || !sandboxCgroupOnly {
+		return NewResourceController(path, &sandboxResources)
+	}
+
+	slice, unit, err := getSliceAndUnit(path)
+	if err != nil {
+		return nil, err
+	}
+	// github.com/containerd/cgroups doesn't support creating a scope unit with
+	// v1 cgroups against systemd, the following interacts directly with systemd
+	// to create the cgroup and then load it using containerd's api
+	err = createCgroupsSystemd(slice, unit, uint32(os.Getpid())) // adding runtime process, it makes calling setupCgroups redundant
+	if err != nil {
+		return nil, err
+	}
+
+	cgHierarchy, cgPath, err := cgroupHierarchy(path)
+	if err != nil {
+		return nil, err
+	}
+
+	// load created cgroup and update with resources
+	if cgroup, err = cgroups.Load(cgHierarchy, cgPath); err == nil {
+		err = cgroup.Update(&sandboxResources)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &LinuxCgroup{
+		path:    path,
+		devices: sandboxResources.Devices,
+		cpusets: sandboxResources.CPU,
+		cgroup:  cgroup,
+	}, nil
+}
+
+func LoadResourceController(path string) (ResourceController, error) {
+	cgHierarchy, cgPath, err := cgroupHierarchy(path)
+	if err != nil {
+		return nil, err
+	}
+
+	cgroup, err := cgroups.Load(cgHierarchy, cgPath)
+	if err != nil {
+		return nil, err
+	}
+
+	return &LinuxCgroup{
+		path:   path,
+		cgroup: cgroup,
+	}, nil
+}
+
+func (c *LinuxCgroup) Logger() *logrus.Entry {
+	return controllerLogger.WithField("source", "cgroups")
+}
+
+func (c *LinuxCgroup) Delete() error {
+	return c.cgroup.Delete()
+}
+
+func (c *LinuxCgroup) Stat() (*v1.Metrics, error) {
+	return c.cgroup.Stat(cgroups.ErrorHandler(cgroups.IgnoreNotExist))
+}
+
+func (c *LinuxCgroup) AddProcess(pid int, subsystems ...string) error {
+	return c.cgroup.Add(cgroups.Process{Pid: pid})
+}
+
+func (c *LinuxCgroup) AddThread(pid int, subsystems ...string) error {
+	return c.cgroup.AddTask(cgroups.Process{Pid: pid})
+}
+
+func (c *LinuxCgroup) Update(resources *specs.LinuxResources) error {
+	return c.cgroup.Update(resources)
+}
+
+func (c *LinuxCgroup) MoveTo(path string) error {
+	cgHierarchy, cgPath, err := cgroupHierarchy(path)
+	if err != nil {
+		return err
+	}
+
+	newCgroup, err := cgroups.Load(cgHierarchy, cgPath)
+	if err != nil {
+		return err
+	}
+
+	return c.cgroup.MoveTo(newCgroup)
+}
+
+func (c *LinuxCgroup) AddDevice(deviceHostPath string) error {
+	deviceResource, err := DeviceToLinuxDevice(deviceHostPath)
+	if err != nil {
+		return err
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	c.devices = append(c.devices, deviceResource)
+
+	if err := c.cgroup.Update(&specs.LinuxResources{
+		Devices: c.devices,
+	}); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *LinuxCgroup) RemoveDevice(deviceHostPath string) error {
+	deviceResource, err := DeviceToLinuxDevice(deviceHostPath)
+	if err != nil {
+		return err
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	for i, d := range c.devices {
+		if d.Type == deviceResource.Type &&
+			d.Major == deviceResource.Major &&
+			d.Minor == deviceResource.Minor {
+			c.devices = append(c.devices[:i], c.devices[i+1:]...)
+		}
+	}
+
+	if err := c.cgroup.Update(&specs.LinuxResources{
+		Devices: c.devices,
+	}); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *LinuxCgroup) UpdateCpuSet(cpuset, memset string) error {
+	c.Lock()
+	defer c.Unlock()
+
+	if len(cpuset) > 0 {
+		// If we didn't have a cpuset defined, let's create:
+		if c.cpusets == nil {
+			c.cpusets = &specs.LinuxCPU{}
+		}
+
+		c.cpusets.Cpus = cpuset
+	}
+
+	if len(memset) > 0 {
+		// If we didn't have a cpuset defined, let's now create:
+		if c.cpusets == nil {
+			c.cpusets = &specs.LinuxCPU{}
+		}
+
+		c.cpusets.Mems = memset
+	}
+
+	return c.cgroup.Update(&specs.LinuxResources{
+		CPU: c.cpusets,
+	})
+}
+
+func (c *LinuxCgroup) Type() ResourceControllerType {
+	return LinuxCgroups
+}
+
+func (c *LinuxCgroup) ID() string {
+	return c.path
+}
+
+func (c *LinuxCgroup) Parent() string {
+	return filepath.Dir(c.path)
+}