oci: join crio-conmon for cgroupfs

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/containerd/cgroups/utils.go

@@ -0,0 +1,280 @@
+package cgroups
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	units "github.com/docker/go-units"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+var isUserNS = runningInUserNS()
+
+// runningInUserNS detects whether we are currently running in a user namespace.
+// Copied from github.com/lxc/lxd/shared/util.go
+func runningInUserNS() bool {
+	file, err := os.Open("/proc/self/uid_map")
+	if err != nil {
+		// This kernel-provided file only exists if user namespaces are supported
+		return false
+	}
+	defer file.Close()
+
+	buf := bufio.NewReader(file)
+	l, _, err := buf.ReadLine()
+	if err != nil {
+		return false
+	}
+
+	line := string(l)
+	var a, b, c int64
+	fmt.Sscanf(line, "%d %d %d", &a, &b, &c)
+	/*
+	 * We assume we are in the initial user namespace if we have a full
+	 * range - 4294967295 uids starting at uid 0.
+	 */
+	if a == 0 && b == 0 && c == 4294967295 {
+		return false
+	}
+	return true
+}
+
+// defaults returns all known groups
+func defaults(root string) ([]Subsystem, error) {
+	h, err := NewHugetlb(root)
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	s := []Subsystem{
+		NewNamed(root, "systemd"),
+		NewFreezer(root),
+		NewPids(root),
+		NewNetCls(root),
+		NewNetPrio(root),
+		NewPerfEvent(root),
+		NewCputset(root),
+		NewCpu(root),
+		NewCpuacct(root),
+		NewMemory(root),
+		NewBlkio(root),
+	}
+	// only add the devices cgroup if we are not in a user namespace
+	// because modifications are not allowed
+	if !isUserNS {
+		s = append(s, NewDevices(root))
+	}
+	// add the hugetlb cgroup if error wasn't due to missing hugetlb
+	// cgroup support on the host
+	if err == nil {
+		s = append(s, h)
+	}
+	return s, nil
+}
+
+// remove will remove a cgroup path handling EAGAIN and EBUSY errors and
+// retrying the remove after a exp timeout
+func remove(path string) error {
+	delay := 10 * time.Millisecond
+	for i := 0; i < 5; i++ {
+		if i != 0 {
+			time.Sleep(delay)
+			delay *= 2
+		}
+		if err := os.RemoveAll(path); err == nil {
+			return nil
+		}
+	}
+	return fmt.Errorf("cgroups: unable to remove path %q", path)
+}
+
+// readPids will read all the pids in a cgroup by the provided path
+func readPids(path string, subsystem Name) ([]Process, error) {
+	f, err := os.Open(filepath.Join(path, cgroupProcs))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	var (
+		out []Process
+		s   = bufio.NewScanner(f)
+	)
+	for s.Scan() {
+		if t := s.Text(); t != "" {
+			pid, err := strconv.Atoi(t)
+			if err != nil {
+				return nil, err
+			}
+			out = append(out, Process{
+				Pid:       pid,
+				Subsystem: subsystem,
+				Path:      path,
+			})
+		}
+	}
+	return out, nil
+}
+
+func hugePageSizes() ([]string, error) {
+	var (
+		pageSizes []string
+		sizeList  = []string{"B", "kB", "MB", "GB", "TB", "PB"}
+	)
+	files, err := ioutil.ReadDir("/sys/kernel/mm/hugepages")
+	if err != nil {
+		return nil, err
+	}
+	for _, st := range files {
+		nameArray := strings.Split(st.Name(), "-")
+		pageSize, err := units.RAMInBytes(nameArray[1])
+		if err != nil {
+			return nil, err
+		}
+		pageSizes = append(pageSizes, units.CustomSize("%g%s", float64(pageSize), 1024.0, sizeList))
+	}
+	return pageSizes, nil
+}
+
+func readUint(path string) (uint64, error) {
+	v, err := ioutil.ReadFile(path)
+	if err != nil {
+		return 0, err
+	}
+	return parseUint(strings.TrimSpace(string(v)), 10, 64)
+}
+
+func parseUint(s string, base, bitSize int) (uint64, error) {
+	v, err := strconv.ParseUint(s, base, bitSize)
+	if err != nil {
+		intValue, intErr := strconv.ParseInt(s, base, bitSize)
+		// 1. Handle negative values greater than MinInt64 (and)
+		// 2. Handle negative values lesser than MinInt64
+		if intErr == nil && intValue < 0 {
+			return 0, nil
+		} else if intErr != nil &&
+			intErr.(*strconv.NumError).Err == strconv.ErrRange &&
+			intValue < 0 {
+			return 0, nil
+		}
+		return 0, err
+	}
+	return v, nil
+}
+
+func parseKV(raw string) (string, uint64, error) {
+	parts := strings.Fields(raw)
+	switch len(parts) {
+	case 2:
+		v, err := parseUint(parts[1], 10, 64)
+		if err != nil {
+			return "", 0, err
+		}
+		return parts[0], v, nil
+	default:
+		return "", 0, ErrInvalidFormat
+	}
+}
+
+func parseCgroupFile(path string) (map[string]string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseCgroupFromReader(f)
+}
+
+func parseCgroupFromReader(r io.Reader) (map[string]string, error) {
+	var (
+		cgroups = make(map[string]string)
+		s       = bufio.NewScanner(r)
+	)
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+		var (
+			text  = s.Text()
+			parts = strings.SplitN(text, ":", 3)
+		)
+		if len(parts) < 3 {
+			return nil, fmt.Errorf("invalid cgroup entry: %q", text)
+		}
+		for _, subs := range strings.Split(parts[1], ",") {
+			if subs != "" {
+				cgroups[subs] = parts[2]
+			}
+		}
+	}
+	return cgroups, nil
+}
+
+func getCgroupDestination(subsystem string) (string, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return "", err
+		}
+		fields := strings.Fields(s.Text())
+		for _, opt := range strings.Split(fields[len(fields)-1], ",") {
+			if opt == subsystem {
+				return fields[3], nil
+			}
+		}
+	}
+	return "", ErrNoCgroupMountDestination
+}
+
+func pathers(subystems []Subsystem) []pather {
+	var out []pather
+	for _, s := range subystems {
+		if p, ok := s.(pather); ok {
+			out = append(out, p)
+		}
+	}
+	return out
+}
+
+func initializeSubsystem(s Subsystem, path Path, resources *specs.LinuxResources) error {
+	if c, ok := s.(creator); ok {
+		p, err := path(s.Name())
+		if err != nil {
+			return err
+		}
+		if err := c.Create(p, resources); err != nil {
+			return err
+		}
+	} else if c, ok := s.(pather); ok {
+		p, err := path(s.Name())
+		if err != nil {
+			return err
+		}
+		// do the default create if the group does not have a custom one
+		if err := os.MkdirAll(c.Path(p), defaultDirPerm); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func cleanPath(path string) string {
+	if path == "" {
+		return ""
+	}
+	path = filepath.Clean(path)
+	if !filepath.IsAbs(path) {
+		path, _ = filepath.Rel(string(os.PathSeparator), filepath.Clean(string(os.PathSeparator)+path))
+	}
+	return filepath.Clean(path)
+}