utils.go 1.3 KB

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  1. package cgroups
  2. import (
  3. "bufio"
  4. "io"
  5. "os"
  6. "strings"
  7. "github.com/dotcloud/docker/pkg/mount"
  8. )
  9. // https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt
  10. func FindCgroupMountpoint(subsystem string) (string, error) {
  11. mounts, err := mount.GetMounts()
  12. if err != nil {
  13. return "", err
  14. }
  15. for _, mount := range mounts {
  16. if mount.Fstype == "cgroup" {
  17. for _, opt := range strings.Split(mount.VfsOpts, ",") {
  18. if opt == subsystem {
  19. return mount.Mountpoint, nil
  20. }
  21. }
  22. }
  23. }
  24. return "", ErrNotFound
  25. }
  26. // Returns the relative path to the cgroup docker is running in.
  27. func GetThisCgroupDir(subsystem string) (string, error) {
  28. f, err := os.Open("/proc/self/cgroup")
  29. if err != nil {
  30. return "", err
  31. }
  32. defer f.Close()
  33. return parseCgroupFile(subsystem, f)
  34. }
  35. func GetInitCgroupDir(subsystem string) (string, error) {
  36. f, err := os.Open("/proc/1/cgroup")
  37. if err != nil {
  38. return "", err
  39. }
  40. defer f.Close()
  41. return parseCgroupFile(subsystem, f)
  42. }
  43. func parseCgroupFile(subsystem string, r io.Reader) (string, error) {
  44. s := bufio.NewScanner(r)
  45. for s.Scan() {
  46. if err := s.Err(); err != nil {
  47. return "", err
  48. }
  49. text := s.Text()
  50. parts := strings.Split(text, ":")
  51. for _, subs := range strings.Split(parts[1], ",") {
  52. if subs == subsystem {
  53. return parts[2], nil
  54. }
  55. }
  56. }
  57. return "", ErrNotFound
  58. }