walnut_launchpad.html/templates/sign-in.html

<form>
  <div class="form-group">
    <label for="exampleInputEmail1">Email address</label>
    <input type="email" class="form-control" placeholder="Email" ng-model="vm.userAuthEmail">
  </div>
  <div class="form-group">
    <label for="exampleInputPassword1">Password</label>
    <input type="password" class="form-control" placeholder="Password" ng-model="vm.userAuthPassword">
  </div>
  <button type="submit" class="btn btn-default" ng-click="vm.sign_in()">Submit</button>
</form>