Function getSubCgroupPaths

exec.go:126–153

getSubCgroupPaths parses --cgroup arguments, which can either be - a single "path" argument (for cgroup v2); - one or more controller[,controller[,...]]:path arguments (for cgroup v1). Returns a controller to path map. For cgroup v2, it's a single entity map with empty controller value.

(args []string)

// Returns a controller to path map. For cgroup v2, it's a single entity map
// with empty controller value.
func getSubCgroupPaths(args []string) (map[string]string, error) {
	if len(args) == 0 {
		return nil, nil
	}
	paths := make(map[string]string, len(args))
	for _, c := range args {
		// Split into controller:path.
		if ctr, path, ok := strings.Cut(c, ":"); ok {
			// There may be a few comma-separated controllers.
			for ctrl := range strings.SplitSeq(ctr, ",") {
				if ctrl == "" {
					return nil, fmt.Errorf("invalid --cgroup argument: %s (empty <controller> prefix)", c)
				}
				if _, ok := paths[ctrl]; ok {
					return nil, fmt.Errorf("invalid --cgroup argument(s): controller %s specified multiple times", ctrl)
				}
				paths[ctrl] = path
			}
		} else {
			// No "controller:" prefix (cgroup v2, a single path).
			if len(args) != 1 {
				return nil, fmt.Errorf("invalid --cgroup argument: %s (missing <controller>: prefix)", c)
			}
			paths[""] = c
		}
	}
	return paths, nil
}

func execProcess(context *cli.Context) (int, error) {
	container, err := getContainer(context)