forked from containerd/cgroups
-
Notifications
You must be signed in to change notification settings - Fork 0
/
paths.go
88 lines (78 loc) · 2.03 KB
/
paths.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
package cgroups
import (
"fmt"
"path/filepath"
"github.com/pkg/errors"
)
type Path func(subsystem Name) (string, error)
func RootPath(subsysem Name) (string, error) {
return "/", nil
}
// StaticPath returns a static path to use for all cgroups
func StaticPath(path string) Path {
return func(_ Name) (string, error) {
return path, nil
}
}
// NestedPath will nest the cgroups based on the calling processes cgroup
// placing its child processes inside its own path
func NestedPath(suffix string) Path {
paths, err := parseCgroupFile("/proc/self/cgroup")
if err != nil {
return errorPath(err)
}
return existingPath(paths, suffix)
}
// PidPath will return the correct cgroup paths for an existing process running inside a cgroup
// This is commonly used for the Load function to restore an existing container
func PidPath(pid int) Path {
p := fmt.Sprintf("/proc/%d/cgroup", pid)
paths, err := parseCgroupFile(p)
if err != nil {
return errorPath(errors.Wrapf(err, "parse cgroup file %s", p))
}
return existingPath(paths, "")
}
func existingPath(paths map[string]string, suffix string) Path {
// localize the paths based on the root mount dest for nested cgroups
for n, p := range paths {
dest, err := getCgroupDestination(string(n))
if err != nil {
return errorPath(err)
}
rel, err := filepath.Rel(dest, p)
if err != nil {
return errorPath(err)
}
if rel == "." {
rel = dest
}
paths[n] = filepath.Join("/", rel)
}
return func(name Name) (string, error) {
root, ok := paths[string(name)]
if !ok {
if root, ok = paths[fmt.Sprintf("name=%s", name)]; !ok {
return "", fmt.Errorf("unable to find %q in controller set", name)
}
}
if suffix != "" {
return filepath.Join(root, suffix), nil
}
return root, nil
}
}
func subPath(path Path, subName string) Path {
return func(name Name) (string, error) {
p, err := path(name)
if err != nil {
return "", err
}
return filepath.Join(p, subName), nil
}
}
func errorPath(err error) Path {
return func(_ Name) (string, error) {
return "", err
}
}