package user import ( "context" "fmt" "os/exec" "strconv" ) // Unix defines an user creation interface for UNIX systems. type Unix struct{} // reference: https://man7.org/linux/man-pages/man8/useradd.8.html#EXIT_VALUES const exitCodeAlreadyInUse = 9 // CreateUser creates a new user with sudo access. func (u Unix) CreateUser(ctx context.Context, username string) error { cmd := exec.CommandContext(ctx, "useradd", "-m", "-G", "wheel,sudo", username) if err := cmd.Run(); err != nil { // do not fail if user already exists if exitError, ok := err.(*exec.ExitError); ok && exitError.ExitCode() == exitCodeAlreadyInUse { return ErrUserOrGroupAlreadyExists } return fmt.Errorf("creating a new user failed: %w", err) } return nil } // CreateUserWithSpecificUIDAndGID creates a new user with sudo access and a specific UID and GID. func (u Unix) CreateUserWithSpecificUIDAndGID(ctx context.Context, username string, uid int, gid int) error { // Add group first with the targeted gid cmd := exec.CommandContext(ctx, "groupadd", "-g", strconv.Itoa(gid), username) if err := cmd.Run(); err != nil { // do not fail if group already exists if exitError, ok := err.(*exec.ExitError); ok && exitError.ExitCode() == exitCodeAlreadyInUse { return ErrUserOrGroupAlreadyExists } return fmt.Errorf("creating a new group failed: %w", err) } // Then, create the user with both the UID and GID assigned. cmd = exec.CommandContext(ctx, "useradd", "-m", "-G", "wheel,sudo", "-u", strconv.Itoa(uid), "-g", strconv.Itoa(gid), username) if err := cmd.Run(); err != nil { // do not fail if user already exists if exitError, ok := err.(*exec.ExitError); ok && exitError.ExitCode() == exitCodeAlreadyInUse { return ErrUserOrGroupAlreadyExists } return fmt.Errorf("creating a new user: %w", err) } return nil }