runc/libcontainer/cgroups/fs2/pids.go

91 lines
2.2 KiB
Go

// +build linux
package fs2
import (
"io/ioutil"
"os"
"path/filepath"
"strconv"
"strings"
"github.com/opencontainers/runc/libcontainer/cgroups"
"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/pkg/errors"
"golang.org/x/sys/unix"
)
func setPids(dirPath string, cgroup *configs.Cgroup) error {
if cgroup.Resources.PidsLimit != 0 {
// "max" is the fallback value.
limit := "max"
if cgroup.Resources.PidsLimit > 0 {
limit = strconv.FormatInt(cgroup.Resources.PidsLimit, 10)
}
if err := fscommon.WriteFile(dirPath, "pids.max", limit); err != nil {
return err
}
}
return nil
}
func isNOTSUP(err error) bool {
switch err := err.(type) {
case *os.PathError:
return err.Err == unix.ENOTSUP
default:
return false
}
}
func statPidsWithoutController(dirPath string, stats *cgroups.Stats) error {
// if the controller is not enabled, let's read PIDS from cgroups.procs
// (or threads if cgroup.threads is enabled)
contents, err := ioutil.ReadFile(filepath.Join(dirPath, "cgroup.procs"))
if err != nil && isNOTSUP(err) {
contents, err = ioutil.ReadFile(filepath.Join(dirPath, "cgroup.threads"))
}
if err != nil {
return err
}
pids := make(map[string]string)
for _, i := range strings.Split(string(contents), "\n") {
if i != "" {
pids[i] = i
}
}
stats.PidsStats.Current = uint64(len(pids))
stats.PidsStats.Limit = 0
return nil
}
func statPids(dirPath string, stats *cgroups.Stats) error {
current, err := fscommon.GetCgroupParamUint(dirPath, "pids.current")
if err != nil {
return errors.Wrap(err, "failed to parse pids.current")
}
maxString, err := fscommon.GetCgroupParamString(dirPath, "pids.max")
if err != nil {
return errors.Wrap(err, "failed to parse pids.max")
}
// Default if pids.max == "max" is 0 -- which represents "no limit".
var max uint64
if maxString != "max" {
max, err = fscommon.ParseUint(maxString, 10, 64)
if err != nil {
return errors.Wrapf(err, "failed to parse pids.max - unable to parse %q as a uint from Cgroup file %q",
maxString, filepath.Join(dirPath, "pids.max"))
}
}
stats.PidsStats.Current = current
stats.PidsStats.Limit = max
return nil
}