rails 使用rucaptcha生成验证码

gem 'rucaptcha', '~> 2.4'

登录页面

<div class="code">
              <div class="form-group row string required code">
                <div class="col-sm-10">
                  <%= rucaptcha_input_tag(class: 'form-control', placeholder: '输入验证码', required: true) %>
                </div>
              </div>
              <div class="code-btn">
                <span><%= rucaptcha_image_tag(alt: '验证码，点击刷新', onclick: "this.src='/rucaptcha/?rand='+Math.random()") %></span>
              </div>
            </div>

登录验证

if !verify_rucaptcha?
      msg_action('验证码不正确')
      return redirect_to message_path
    end