Bootstrap full-width text-input within inline-form

I am struggling to create a textbox that fits the entire width of my container area.

<div class="row">
    <div class="col-md-12">
        <form class="form-inline" role="form">           
                <input type="text" class="form-control input-lg" id="search-church" placeholder="Your location (City, State, ZIP)">
                <button type="submit" class="btn btn-lg">Search</button>            
        </form>
    </div>
</div>

When I do the above, the two form elements are in-line, as I expect, but don't take up more than a few columns, at best. Hovering over the col-md-12 div in firebug shows it taking up the expected full width. It's just the text input that doesn't seem to fill. I even tried adding an in-line width value but it didn't change anything. I know this should be simple, just feeling really dumb now.

Here is a fiddle: http://jsfiddle.net/52VtD/4119/embedded/result/

EDIT:

The selected answer is thorough in every way and a wonderful help. It's what I ended up using. However I think my initial issue was actually a problem with the default MVC5 template within Visual Studio 2013. It contained this in Site.css:

input,
select,
textarea {
    max-width: 280px;
}

Obviously that was blocking the text-input from expanding appropriately... Fair warning to future ASP.NET template users...

The bootstrap docs says about this:

> Requires custom widths Inputs, selects, and textareas are 100% wide by > default in Bootstrap. To use the inline form, you'll have to set a > width on the form controls used within.

The default width of 100% as all form elements gets when they got the class form-control didn't apply if you use the form-inline class on your form.

You could take a look at the bootstrap.css (or .less, whatever you prefer) where you will find this part:

.form-inline {

  // Kick in the inline
  @media (min-width: @screen-sm-min) {
    // Inline-block all the things for "inline"
    .form-group {
      display: inline-block;
      margin-bottom: 0;
      vertical-align: middle;
    }

    // In navbar-form, allow folks to *not* use `.form-group`
    .form-control {
      display: inline-block;
      width: auto; // Prevent labels from stacking above inputs in `.form-group`
      vertical-align: middle;
    }
    // Input groups need that 100% width though
    .input-group > .form-control {
      width: 100%;
    }
   
    [...]
  }
}

Maybe you should take a look at input-groups, since I guess they have exactly the markup you want to use (working fiddle here):

<div class="row">
   <div class="col-lg-12">
    <div class="input-group input-group-lg">
      <input type="text" class="form-control input-lg" id="search-church" placeholder="Your location (City, State, ZIP)">
      <span class="input-group-btn">
        <button class="btn btn-default btn-lg" type="submit">Search</button>
      </span>
    </div>
  </div>
</div>

have a look at something like this:

<form role="form">  
    <div class="row">
      <div class="col-xs-12">
        <div class="input-group input-group-lg">
            <input type="text" class="form-control" />
          <div class="input-group-btn">
            <button type="submit" class="btn">Search</button>
          </div><!-- /btn-group -->
        </div><!-- /input-group -->
      </div><!-- /.col-xs-12 -->
    </div><!-- /.row -->
</form>

http://jsfiddle.net/n6c7v/1/

As stated in a similar question, try removing instances of the input-group class and see if that helps.

refering to bootstrap:

> Individual form controls automatically receive some global styling. > All textual , , and <select> elements with > .form-control are set to width: 100%; by default. Wrap labels and > controls in .form-group for optimum spacing.</p>

> Try something like below to achieve your desired result

input {
    max-width: 100%;
}

With Bootstrap >4.1 it's just a case of using the flexbox utility classes. Just have a flexbox container inside your column, and then give all the elements within it the "flex-fill" class. As with inline forms you'll need to set the margins/padding on the elements yourself.

.prop-label {
    margin: .25rem 0 !important;
}

.prop-field {
    margin-left: 1rem;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet"/>
<div class="row">
	<div class="col-12">
		<div class="d-flex">
			<label class="flex-fill prop-label">Label:</label>
			<input type="text" class="flex-fill form-control prop-field">
		</div>
	</div>
</div>

I know that this question is pretty old, but I stumbled upon it recently, found a solution that I liked better, and figured I'd share it.

Now that Bootstrap 5 is available, there's a new approach that works similarly to using input-groups, but looks more like an ordinary form, without any CSS tweaks:

<div class="row g-3 align-items-center">
    <div class="col-auto">
        <label>Label:</label>
    </div>
    <div class="col">
        <input class="form-control">
    </div>
    <div class="col-auto">
        <button type="button" class="btn btn-primary">Button</button>
    </div>
</div>

The col-auto class makes those columns fit themselves to their contents (the label and the button in this case), and anything with a col class should be evenly distributed to take up the remaining space.

You can use flex-fill class for input

<div class="row">
<div class="col-md-12">
    <form class="form-inline" role="form">           
            <input type="text" class="form-control input-lg flex-fill" id="search-church" placeholder="Your location (City, State, ZIP)">
            <button type="submit" class="btn btn-lg">Search</button>            
    </form>
</div>