Using errgroup

errgroup.go

eg, ctx := errgroup.WithContext(ctx)
eg.Go(func() error {
	defer close(lines)
	for {
		if !scanner.Scan() {
			fmt.Println("Reader: Completed")
			break
		}
		lines <- scanner.Text()

		select {
		case <-ctx.Done():
			fmt.Println("Reader: Context closed")
			return ctx.Err()
		default:
		}
	}

	if err := scanner.Err(); err != nil {
		return fmt.Errorf("reader error - %w", err)
	}
	return nil
})

eg.Go(func() error {
	for {
		select {
		case <-ctx.Done():
			fmt.Println("Sender: Context closed")
			return ctx.Err()
		case l, ok := <-lines:
			if !ok {
				fmt.Printf("Sender: Channel closed\n", l)
				return nil
			}
			fmt.Printf("Sender: Sending %s to remote database\n", l)
		}
	}
})

err = eg.Wait()
if err != nil {
	fmt.Printf("error from goroutine - %v\n", err)
}