Vertical flexbox

Header sized to content, with fixed footer, and content region that fills the remaining space.

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css">
<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>
<nav class="navbar navbar-toggleable-md navbar-inverse bg-inverse">
  <div class="container">
    <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <a class="navbar-brand" href="#">Navbar</a>

    <div class="collapse navbar-collapse" id="navbarTogglerDemo02">
      <ul class="navbar-nav mr-auto mt-2 mt-md-0">
        <li class="nav-item active">
          <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item">
          <a class="nav-link disabled" href="#">Disabled</a>
        </li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="text" placeholder="Search">
        <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
      </form>
    </div>
  </div>
</nav>

<div class="container">
  <div class="row mt-4">
    <div class="col-12">
      <div class="card">
        <div class="card-block">
          content
          <br> content
          <br> content
          <br> content
          <br> content
          <br> content
          <br> content
          <br> content
          <br> content
          <br> content
          <br>
        </div>
      </div>
    </div>
  </div>
</div>

SCSS

body {
  background: #90a4ae;
}

.container .navbar-toggler-right {
  right: 0;
}