Function generateCgroupPath

pkg/cmd/container/run_cgroup_linux.go:230–266

(id, cgroupManager, cgroupParent string)

}

func generateCgroupPath(id, cgroupManager, cgroupParent string) (string, error) {
	var (
		path         string
		usingSystemd = cgroupManager == "systemd"
		slice        = "system.slice"
		scopePrefix  = ":nerdctl:"
	)
	if rootlessutil.IsRootlessChild() {
		slice = "user.slice"
	}

	if cgroupParent == "" {
		if usingSystemd {
			// "slice:prefix:name"
			path = slice + scopePrefix + id
		}
		// Nothing to do for the non-systemd case if a parent wasn't supplied,
		// containerd already sets a default cgroup path as /<namespace>/<containerID>
		return path, nil
	}

	// If the user asked for a cgroup parent, we will use systemd,
	// Docker uses the following:
	// parent + prefix (in our case, nerdctl) + containerID.
	//
	// In the non systemd case, it's just /parent/containerID
	if usingSystemd {
		if len(cgroupParent) <= 6 || !strings.HasSuffix(cgroupParent, ".slice") {
			return "", errors.New(`cgroup-parent for systemd cgroup should be a valid slice named as "xxx.slice"`)
		}
		path = cgroupParent + scopePrefix + id
	} else {
		path = filepath.Join(cgroupParent, id)
	}

	return path, nil
}

// ParseDevice parses the give device string into hostDevPath, containerPath and mode(defaults: "rwm").
func ParseDevice(s string) (hostDevPath string, containerPath string, mode string, err error) {