mirror of
https://github.com/k3s-io/k3s.git
synced 2024-06-07 19:41:36 +00:00
105 lines
2.6 KiB
Go
105 lines
2.6 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 (
|
|
"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
|
|
}
|
|
}
|