packer-cn/website/source/layouts/intro.erb

<% wrap_layout :inner do %>
  <% content_for :sidebar do %>
    <div class="docs-sidebar hidden-print affix-top" role="complementary">
      <ul class="nav docs-sidenav">
        <li<%= sidebar_current("intro-why") %>>
          <a href="/intro/why.html">Why Use Packer?</a>
        </li>
        <li<%= sidebar_current("intro-use-cases") %>>
          <a href="/intro/use-cases.html">Use Cases</a>
        </li>
        <li<%= sidebar_current("intro-ecosystem") %>>
          <a href="/intro/hashicorp-ecosystem.html">Packer &amp; HashiCorp</a>
        </li>

        <li<%= sidebar_current("intro-getting-started") %>>
          <a href="/intro/getting-started/install.html">Getting Started</a>
          <ul class="nav">
            <li<%= sidebar_current("intro-getting-started-install") %>>
              <a href="/intro/getting-started/install.html">Install Packer</a>
            </li>
            <li<%= sidebar_current("intro-getting-started-build-image") %>>
              <a href="/intro/getting-started/build-image.html">Build an Image</a>
            </li>
            <li<%= sidebar_current("intro-getting-started-provision") %>>
              <a href="/intro/getting-started/provision.html">Provision</a>
            </li>
            <li<%= sidebar_current("intro-getting-started-parallel-builds") %>>
              <a href="/intro/getting-started/parallel-builds.html">Parallel Builds</a>
            </li>
            <li<%= sidebar_current("intro-getting-started-vagrant") %>>
              <a href="/intro/getting-started/vagrant.html">Vagrant Boxes</a>
            </li>
            <li<%= sidebar_current("intro-getting-started-remote-builds") %>>
              <a href="/intro/getting-started/remote-builds.html">Remote Builds</a>
            </li>
            <li<%= sidebar_current("intro-getting-started-next") %>>
              <a href="/intro/getting-started/next.html">Next Steps</a>
            </li>
          </ul>
        </li>
      </ul>
    </div>
  <% end %>

  <%= yield %>
<% end %>