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authorflouthoc <flouthoc.git@gmail.com>2021-05-19 01:19:20 +0530
committerflouthoc <flouthoc.git@gmail.com>2021-05-24 16:55:23 +0530
commit2f5552c32d01678bfbfdbb8838e1672d62521a6c (patch)
treec17b87d13c922a500cef1e8cb20580237cc2191c /pkg/cgroups
parentb060a7726e8e97f7752b40f18e69236cb330d22d (diff)
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Podman info add support for status of cgroup controllers
Signed-off-by: flouthoc <flouthoc.git@gmail.com>
Diffstat (limited to 'pkg/cgroups')
-rw-r--r--pkg/cgroups/cgroups.go106
1 files changed, 98 insertions, 8 deletions
diff --git a/pkg/cgroups/cgroups.go b/pkg/cgroups/cgroups.go
index aefb5183b..911edeb5b 100644
--- a/pkg/cgroups/cgroups.go
+++ b/pkg/cgroups/cgroups.go
@@ -128,28 +128,118 @@ func init() {
// getAvailableControllers get the available controllers
func getAvailableControllers(exclude map[string]controllerHandler, cgroup2 bool) ([]controller, error) {
if cgroup2 {
- return nil, fmt.Errorf("getAvailableControllers not implemented yet for cgroup v2")
+ controllers := []controller{}
+ subtreeControl := cgroupRoot + "/cgroup.subtree_control"
+ // rootless cgroupv2: check available controllers for current user ,systemd or servicescope will inherit
+ if rootless.IsRootless() {
+ userSlice, err := getCgroupPathForCurrentProcess()
+ if err != nil {
+ return controllers, err
+ }
+ //userSlice already contains '/' so not adding here
+ basePath := cgroupRoot + userSlice
+ subtreeControl = fmt.Sprintf("%s/cgroup.subtree_control", basePath)
+ }
+ subtreeControlBytes, err := ioutil.ReadFile(subtreeControl)
+ if err != nil {
+ return nil, errors.Wrapf(err, "failed while reading controllers for cgroup v2 from %q", subtreeControl)
+ }
+ for _, controllerName := range strings.Fields(string(subtreeControlBytes)) {
+ c := controller{
+ name: controllerName,
+ symlink: false,
+ }
+ controllers = append(controllers, c)
+ }
+ return controllers, nil
}
- infos, err := ioutil.ReadDir(cgroupRoot)
- if err != nil {
- return nil, err
- }
+ subsystems, _ := cgroupV1GetAllSubsystems()
controllers := []controller{}
- for _, i := range infos {
- name := i.Name()
+ // cgroupv1 and rootless: No subsystem is available: delegation is unsafe.
+ if rootless.IsRootless() {
+ return controllers, nil
+ }
+
+ for _, name := range subsystems {
if _, found := exclude[name]; found {
continue
}
+ isSymLink := false
+ fileInfo, err := os.Stat(cgroupRoot + "/" + name)
+ if err != nil {
+ isSymLink = !fileInfo.IsDir()
+ }
c := controller{
name: name,
- symlink: !i.IsDir(),
+ symlink: isSymLink,
}
controllers = append(controllers, c)
}
+
return controllers, nil
}
+// GetAvailableControllers get string:bool map of all the available controllers
+func GetAvailableControllers(exclude map[string]controllerHandler, cgroup2 bool) ([]string, error) {
+ availableControllers, err := getAvailableControllers(exclude, cgroup2)
+ if err != nil {
+ return nil, err
+ }
+ controllerList := []string{}
+ for _, controller := range availableControllers {
+ controllerList = append(controllerList, controller.name)
+ }
+
+ return controllerList, nil
+}
+
+func cgroupV1GetAllSubsystems() ([]string, error) {
+ f, err := os.Open("/proc/cgroups")
+ if err != nil {
+ return nil, err
+ }
+ defer f.Close()
+
+ subsystems := []string{}
+
+ s := bufio.NewScanner(f)
+ for s.Scan() {
+ text := s.Text()
+ if text[0] != '#' {
+ parts := strings.Fields(text)
+ if len(parts) >= 4 && parts[3] != "0" {
+ subsystems = append(subsystems, parts[0])
+ }
+ }
+ }
+ if err := s.Err(); err != nil {
+ return nil, err
+ }
+ return subsystems, nil
+}
+
+func getCgroupPathForCurrentProcess() (string, error) {
+ path := fmt.Sprintf("/proc/%d/cgroup", os.Getpid())
+ f, err := os.Open(path)
+ if err != nil {
+ return "", err
+ }
+ defer f.Close()
+
+ cgroupPath := ""
+ s := bufio.NewScanner(f)
+ for s.Scan() {
+ text := s.Text()
+ procEntries := strings.SplitN(text, "::", 2)
+ cgroupPath = procEntries[1]
+ }
+ if err := s.Err(); err != nil {
+ return cgroupPath, err
+ }
+ return cgroupPath, nil
+}
+
// getCgroupv1Path is a helper function to get the cgroup v1 path
func (c *CgroupControl) getCgroupv1Path(name string) string {
return filepath.Join(cgroupRoot, name, c.path)