mirror of https://github.com/k3s-io/k3s
82 lines
2.2 KiB
Go
82 lines
2.2 KiB
Go
|
/*
|
||
|
|
Copyright The containerd Authors.
|
||
|
|
|
||
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
you may not use this file except in compliance with the License.
|
||
|
|
You may obtain a copy of the License at
|
||
|
|
|
||
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
|
||
|
|
Unless required by applicable law or agreed to in writing, software
|
||
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
See the License for the specific language governing permissions and
|
||
|
|
limitations under the License.
|
||
|
|
*/
|
||
|
|
|
||
|
|
package cgroups
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bufio"
|
||
|
|
"fmt"
|
||
|
|
"os"
|
||
|
|
"path/filepath"
|
||
|
|
"strings"
|
||
|
|
)
|
||
|
|
|
||
|
|
// V1 returns all the groups in the default cgroups mountpoint in a single hierarchy
|
||
|
|
func V1() ([]Subsystem, error) {
|
||
|
|
root, err := v1MountPoint()
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
subsystems, err := defaults(root)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
var enabled []Subsystem
|
||
|
|
for _, s := range pathers(subsystems) {
|
||
|
|
// check and remove the default groups that do not exist
|
||
|
|
if _, err := os.Lstat(s.Path("/")); err == nil {
|
||
|
|
enabled = append(enabled, s)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return enabled, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// v1MountPoint returns the mount point where the cgroup
|
||
|
|
// mountpoints are mounted in a single hiearchy
|
||
|
|
func v1MountPoint() (string, error) {
|
||
|
|
f, err := os.Open("/proc/self/mountinfo")
|
||
|
|
if err != nil {
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
defer f.Close()
|
||
|
|
scanner := bufio.NewScanner(f)
|
||
|
|
for scanner.Scan() {
|
||
|
|
if err := scanner.Err(); err != nil {
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
var (
|
||
|
|
text = scanner.Text()
|
||
|
|
fields = strings.Split(text, " ")
|
||
|
|
// safe as mountinfo encodes mountpoints with spaces as \040.
|
||
|
|
index = strings.Index(text, " - ")
|
||
|
|
postSeparatorFields = strings.Fields(text[index+3:])
|
||
|
|
numPostFields = len(postSeparatorFields)
|
||
|
|
)
|
||
|
|
// this is an error as we can't detect if the mount is for "cgroup"
|
||
|
|
if numPostFields == 0 {
|
||
|
|
return "", fmt.Errorf("Found no fields post '-' in %q", text)
|
||
|
|
}
|
||
|
|
if postSeparatorFields[0] == "cgroup" {
|
||
|
|
// check that the mount is properly formated.
|
||
|
|
if numPostFields < 3 {
|
||
|
|
return "", fmt.Errorf("Error found less than 3 fields post '-' in %q", text)
|
||
|
|
}
|
||
|
|
return filepath.Dir(fields[4]), nil
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return "", ErrMountPointNotExist
|
||
|
|
}
|