horizon - forms - issue with form_action:

gistfile1.txt

The issue is: when the form_action in my _create.html is specified this way: {% block form_action %}{% url 'workloads_panel:create' %}{% endblock %} - I get NoReverseMatch: u'workloads_panel' is not a registered namespace;   "GET /mydashboard/workloads_panel/create/ HTTP/1.1" 500 35672

Here is my directory structure under openstack_dashboard/dashboards/mydashboard:
.
├── blueprints_panel
│   ├── __init__.py
│   ├── __init__.pyc
│   ├── models.py
│   ├── models.pyc
│   ├── panel.py
│   ├── panel.pyc
│   ├── tables.py
│   ├── tables.pyc
│   ├── tabs.py
│   ├── tabs.pyc
│   ├── templates
│   │   └── blueprints_panel
│   │       └── index.html
│   ├── tests.py
│   ├── tests.pyc
│   ├── urls.py
│   ├── urls.pyc
│   ├── views.py
│   └── views.pyc
├── dashboard.py
├── dashboard.pyc
├── __init__.py
├── __init__.pyc
├── models.py
├── models.pyc
├── software_packages_panel
│   ├── __init__.py
│   ├── __init__.pyc
│   ├── models.py
│   ├── panel.py
│   ├── panel.pyc
│   ├── tables.py
│   ├── tables.pyc
│   ├── tabs.py
│   ├── tabs.pyc
│   ├── templates
│   │   └── software_packages_panel
│   │       └── index.html
│   ├── urls.py
│   ├── urls.pyc
│   ├── views.py
│   └── views.pyc
├── static
│   └── mydashboard
│       ├── css
│       │   └── mydashboard.css
│       └── js
│           └── mydashboard.js
├── templates
│   └── mydashboard
│       ├── base.html
│       └── workload_detail.html
└── workloads_panel
    ├── forms.py
    ├── forms.pyc
    ├── __init__.py
    ├── __init__.pyc
    ├── models.py
    ├── panel.py
    ├── panel.pyc
    ├── tables.py
    ├── tables.pyc
    ├── tabs.py
    ├── tabs.pyc
    ├── templates
    │   └── workloads_panel
    │       ├── _create.html
    │       ├── create.html
    │       └── index.html
    ├── urls.py
    ├── urls.pyc
    ├── views.py
    ├── views.pyc
    ├── workflows.py
    └── workflows.pyc


Here is the workloads_panel/urls.py:

from django.conf.urls import patterns
from django.conf.urls import url

from openstack_dashboard.dashboards.mydashboard.workloads_panel import views
from openstack_dashboard.dashboards.mydashboard.workloads_panel.views import UpdateView

RESOURCE_CLASS = r'^(?P<resource_class_id>[^/]+)/%s$'

urlpatterns = patterns('',
    url(r'^create/$', views.CreateView.as_view(), name='create'),
    url(r'^$', views.IndexView.as_view(), name='index'),
    url(r'^\?tab=workloads_tabs_tab$',
       views.IndexView.as_view(), name='workloads_tabs'),
    url(r'^(?P<instance_id>[^/]+)/$',
        views.UpdateView.as_view(), name='update'),
    url(RESOURCE_CLASS % 'update', UpdateView.as_view(), name='update'),
)


Here is the workloads_panel/templates/workloads_panel/create.html

{% extends 'base.html' %}
{% load i18n %}
{% block title %}{% trans "Create Workload" %}{% endblock %}

{% block page_header %}
  {% include "horizon/common/_page_header.html" with title=_("Create Workload") %}
{% endblock page_header %}

{% block main %}
  {% include "_create.html" %}
{% endblock %}

Here is Here is the workloads_panel/templates/workloads_panel/_create.html

{% extends "horizon/common/_modal_form.html" %}
{% load i18n %}
{% load url from future %}

{% block form_id %}create_workload_form{% endblock %}
{% block form_action %}{% url 'workloads_panel:create' %}{% endblock %}

{% block modal_id %}create_workload_modal{% endblock %}
{% block modal-header %}{% trans "Create Workload" %}{% endblock %}

{% block modal-body %}
<div class="left">
    <fieldset>
        {% include "horizon/common/_form_fields.html" %}
    </fieldset>
</div>
<div class="right">
    <h3>{% trans "Description:" %}</h3>
    <p>{% trans "Create a new Workload."%}</p>
    <p>{% trans "A Workload includes OS type from Images and Size from Flavors"%}</p>

</div>
{% endblock %}

{% block modal-footer %}
  <input class="btn btn-primary pull-right" type="submit" value="{% trans "Create Workload" %}" />
  <a href="{% url 'horizon:admin:networks:index' %}" class="btn btn-default secondary cancel close">{% trans "Cancel" %}</a>
{% endblock %}

Here is workloads_panel/views.py (partial)

class CreateView(forms.ModalFormView):
    form_class = project_forms.CreateWorkloadForm
    template_name = 'create.html'

Here is workloads_panel/forms.py

class CreateWorkloadForm(forms.SelfHandlingForm):
    name = forms.CharField(max_length="255", label=_("Workload Name"))
    description = forms.CharField(widget=forms.Textarea,
            label=_("Description"), required=False)

    def __init__(self, request, *args, **kwargs):
        super(CreateWorkloadForm, self).__init__(request, *args, **kwargs)

        # populate volume_id
        volume_id = kwargs.get('initial', {}).get('volume_id', [])
        self.fields['volume_id'] = forms.CharField(widget=forms.HiddenInput(),
                                                   initial=volume_id)

    def handle(self, request, data):
        try:

            message = _('Creating Workload')

            messages.info(request, message)
            return True
        except Exception:
            redirect = reverse("horizon:project:volumes:index")
            exceptions.handle(request,
                              _('Unable to create Workload.'),
                              redirect=redirect)

I'm no Django expert, but @ line 93 where you have
urlpatterns = patterns('',

I think you want something like
urlpatterns = patterns('openstack_dashboard.dashboards.workloads_panel.views',
to describe where your views are found

relevant doc:
https://docs.djangoproject.com/en/1.7/ref/urls/