django.contrib.auth

urlpatterns = patterns('',
    #...
    url(r'^login/$', 'django.contrib.auth.views.login',
        {'template_name': 'workshops/login.html'}, name='login'),

    url(r'^logout/$', 'django.contrib.auth.views.logout',
        name='logout'),
    #...
)

template:
    <form class="form-signin" role="form" method="post" action="{% url 'django.contrib.auth.views.login' %}">
        {% csrf_token %}
        {% if form.errors %}
            <p class="warning">The username or password you entered is incorrect.</p>
        {% endif %}
        <h2 class="form-signin-heading">Sign in</h2>
        {{ form.username | add_class:'form-control' | attr:'placeholder:Username' | attr:'required autofocus' }}
        {{ form.password | add_class:'form-control' | attr:'placeholder:Password' | attr:'required' }}
        <button class="btn btn-lg btn-primary btn-block" type="submit">Submit</button>
    </form>










                    {% if user.is_authenticated %}
                        Logged in as: <a href="{% url 'person' user.username %}">{{ user.person }}</a>
                    </li>
                    <li>
                        <a href="{% url 'logout' %}?next={% url 'workshops' %}">Logout</a>
                    {% else %}
                        <a href="{% url 'login' %}">Login</a>
                    {% endif %}
                    </li>