20141001 delapsley-oc-openstack-final

Enhancing OpenStack Horizon with
AngularJS
#openstackmeetupoc
David Lapsley
@devlaps, david.lapsley@metacloud.com
October 1, 2014

OpenStack Clouds
Architecture and Model

OpenStack Model
http://docs.openstack.org/openstack-ops/content/example_architecture.html
http://docs.openstack.org/training-guides/content/module001-ch004-openstack-architecture.html

OpenStack Projects
● Compute (Nova)
● Network (Nova, Neutron)
● VM Registration (Glance)
● Identity (Keystone)
● Object Storage (Swift, …)
● Block Storage (Cinder)
● Dashboard (Horizon)

OpenStack Horizon
Architecture

Horizon Overview
● Django-based application deployed via
Apache and WSGI
● Provides access to OpenStack services
● Leverages existing technologies
o Bootstrap, jQuery, Underscore.js,
AngularJS, D3.js, Rickshaw, LESS CSS
● Extends Django to enhance extensibility

Horizon UI
Nav entries Column sorting
Linking
Filtering Table actions
Data retrieval RPC
Row actions
Multi-select

AngularJS lets you extend HTML vocabulary
for your application. The resulting environment
is extraordinarily expressive, readable, and
quick to develop.
https://angularjs.org

Develop smaller, lighter web apps that are
simple to create and easy to test, extend and
maintain as they grow
Brad Green, Shyam Seshadri, “AngularJS”

Core concepts
● Model View Controller framework
● Client-side templates
● Data binding
● Dependency injection

Hello World
index.html
<html ng-app>
<head>
<script src="angular.js"></script>
<script src="controllers.js"></script>
</head>
<body>
<div ng-controller='HelloController'>
<p>{{greeting.text}}, World</p>
<button ng-click="action()">Alert</button>
</div>
</body>
</html>
controllers.js
function HelloController($scope) {
$scope.greeting = { text: 'Hello' };
$scope.action = function() {
alert('Action!');
};
}
AngularJS
By: Brad Green; Shyam Seshadri
Publisher: O'Reilly Media, Inc.
Pub. Date: April 23, 2013

Hello World
Controller
function HelloController($scope) {
$scope.greeting = { text: 'Hello' };
$scope.action = function() {
alert('Action!');
};
}
Scope
View
<html ng-app>
<head>
<script src="angular.js"></script>
<script src="controllers.js"></script>
</head>
<body>
<div ng-controller='HelloController'>
<p>{{greeting.text}}, World</p>
<button ng-click="action()">Alert</button>
</div>
</body>
</html>
{
greeting: { text: 'Hello' };
action: function;
}

Adding a new Panel
Using current Horizon

Dashboards & Panels
● Horizon provides a flexible framework for
creating Dashboards and Panels
● Panels grouped into PanelGroups
● PanelGroups into Dashboards

Dashboard App
● Dashboards created as Django Applications
● Dashboard modules partitioned into:
o static
o templates
o python modules

Directory Structure
openstackoc/
__init__.py
dashboard.py
templates/
openstackoc/
static/
openstackoc/
css/
img/
js/

_10_openstackoc.py
DASHBOARD = 'openstackoc'
DISABLED = False
ADD_INSTALLED_APPS = [
'openstack_dashboard.dashboards.openstackoc',
]

dashboard.py
class BasePanelGroup(horizon.PanelGroup):
slug = "overview"
name = _("Overview")
panels = ("hypervisors",)
class OpenstackOC(horizon.Dashboard):
name = _("OpenstackOC")
slug = "OpenstackOC"
panels = (BasePanelGroup,)
default_panel = "hypervisors"
roles = ("admin",)
horizon.register(OpenstackOC)

Dashboard
Dashboard
PanelGroup

Panel
● Panels are created as Python Modules
● Panel modules partitioned into:
o static/
o templates/
o python modules:
 urls.py, views.py, panel.py
 tables.py, forms.py, tabs.py, tests.py

Directory Structure
openstackoc/
hypervisors/
__init__.py
panel.py
urls.py
views.py
tests.py
tables.py
templates/
openstackoc/
hypervisors/
index.html
static/
openstackoc/
hypervisors/

panel.py
from django.utils.translation import ugettext_lazy as _
import horizon
from openstack_dashboard.dashboards.openstackoc import dashboard
class Hypervisors(horizon.Panel):
name = _("Hypervisors")
slug = 'hypervisors'
dashboard.OpenstackOC.register(Hypervisors)

Dashboard
Dashboard
PanelGroup
Panel

View Module
● View module ties together everything:
o Tables, Templates, API Calls
● Horizon base views:
o APIView, LoginView, MultiTableView,
DataTableView, MixedDataTableView,
TabView, TabbedTableView, WorkflowView

views.py
from horizon import tables
class HypervisorsIndexView(tables.DataTableView):
table_class = hv_tables.AdminHypervisorsTable
template_name = ’openstackoc/hypervisors/index.html’
def get_data(self):
hypervisors = []
states = {}
hypervisors = api.nova.hypervisor_list(self.request)
…
return hypervisors

Table Module
● Table classes provide framework for tables:
o consistent look and feel
o configurable table_actions and row_actions
o select/multi-select column
o sorting
o pagination
● Functionality is split server- and client-side

tables.py
class EnableAction(tables.BatchAction):
…
class DisableAction(tables.BatchAction):
name = 'disable'
classes = ('btn-danger',)
def allowed(self, request, hv):
return hv.service.get('status') == 'enabled'
def action(self, request, obj_id):
hv = api.nova.hypervisor_get(request, obj_id)
host = getattr(hv, hv.NAME_ATTR)
return api.nova.service_disable(request, host, 'nova-compute')
def search_link(x):
return '/admin/instances?q={0}'.format(x.hypervisor_hostname)

tables.py
class AdminHypervisorsTable(tables.DataTable):
hypervisor_hostname = tables.Column(
'hypervisor_hostname', verbose_name=_('Hostname'))
state = tables.Column(
lambda hyp: hyp.service.get('state', _('UNKNOWN')).title(),
verbose_name=_('State'))
running_vms = tables.Column(
'running_vms', link=search_link, verbose_name=_('Instances'))
...
class Meta:
name = 'hypervisors'
verbose_name = _('Hypervisors')
row_actions = (EnableAction, DisableAction)

Template
● Standard Django template format
● Typically leverage base horizon templates
(e.g. base.html)

index.html
{% extends 'base.html' %}
{% load i18n horizon humanize sizeformat %}
{% block title %}{% trans 'Hypervisors' %}{% endblock %}
{% block page_header %}
{% include 'horizon/common/_page_header.html' with title=_('All
Hypervisors') %}
{% endblock page_header %}
{% block main %}
<div class="quota-dynamic">
<h3>{% trans "Hypervisor Summary" %}</h3>
<div class="d3_quota_bar">
<div class="d3_pie_chart" …></div>
</div>
…
</div>
<div class="row-fluid">
<div class="col-sm-12">
{{ tab_group.render }}
</div>
</div>
{% endblock %}

URLs Modules
● Provides URL to View mappings

urls.py
from django.conf.urls import patterns
from django.conf.urls import url
from openstack_dashboard.dashboards.openstackoc.hypervisors import views
urlpatterns = patterns(
'openstack_dashboard.dashboards.openstackoc.hypervisors.views'
url(r'^$', views.IndexView.as_view(), name='index'),
)

Completed Dashboard
Nav entries
Column sorting
Panel rendering
Linking
Data retrieval RPC

Adding a new Panel
with AngularJS

Directory Structure
openstackoc/
hypervisors/
__init__.py
panel.py
urls.py
views.py
tables.py
tests.py
templates/openstackoc/hypervisors/
index.html
static/openstackoc/hypervisors/js/
hypervisors-controller.js
rest/nova/
__init__.py
hypervisor.py
instance.py

REST Resource
● Provides the source of data via RESTful API
● Resource includes/provides:
o entity data/state
o configurable table_actions and row_actions
o sorting
o pagination
o CRUD operations

hypervisors.py
class HypervisorResource(resource.BaseNovaResource):
pk = fields.CharField(attribute="pk",
_("Primary Key"),
hidden=True)
hypervisor_hostname = fields.CharField(attribute='hypervisor_hostname',
sortable=True,
searchable=True)
…
actions = fields.ActionsField(attribute='actions',
actions=[HypervisorViewLiveStats,
HypervisorEnableAction,
HypervisorDisableAction],
title=_("Actions"),
sortable=True)
class Meta:
authorization = auth.RestAuthorization()
list_allowed_methods = ['get']
resource_name = '^hypervisor'
field_order = ['pk', 'hypervisor_hostname', 'hypervisor_type', 'vcpus',
'vcpus_used', 'memory_mb', 'memory_mb_used',
'running_vms', 'state', 'status', 'actions']

Controller
● Controls view logic

hypervisor-controller.js
horizonApp.controller('TableController',
function($scope, $http) {
$scope.headers = headers;
$scope.title = title;
$http.get('/rest/api/v1/nova/instance/').success(
function(data, status, headers, config) {
$scope.instances = data;
});
});
horizonApp.controller('ActionDropdownController',
function($scope) {
$scope.status = {
isopen: false
};
$scope.toggleDropdown = function($event) {
$event.preventDefault();
$event.stopPropagation();
$scope.status.isopen = !$scope.status.isopen;
};
$scope.action = function(action, id) {
// Perform action.
};
…
});

View
● In AngularJS, view is defined in the HTML
template

index.html
{% extends 'base.html' %}
{% load i18n horizon humanize sizeformat %}
{% block title %}{% trans 'Hypervisors' %}{% endblock %}
{% block page_header %}
{% include 'horizon/common/_page_header.html' with title=_('All
Hypervisors') %}
{% endblock page_header %}
{% block main %}

index.html
<div ng-controller="TableController">
<table class="...">
<thead>
<tr class="...">
<th class="...">
<h3 class="...">{$ title $}</h3>
</th>
</tr>
<tr class="...">
<th class="..." ng-repeat='header in headers'>
<div class="...">{$ header.name $}</div>
</th>
</tr>
</thead>

index.html
<tr ng-repeat="instance in instances">
<td ng-repeat="datum in instance.data">{$ datum $}</td>
<td class="...">
<div ng-controller="ActionDropdownController">
<div class="..." dropdown>
<button class="..."
ng-click="action(instance.actions[0], instance.name)">
{$ instance.actions[0].verbose_name $}
</button>
...
<div class="...">
<li class="..." ng-repeat="action in instance.actions">
<a href="#" class="..."
ng-click="$parent.action(action,parent.instance.name)">
{$ action.verbose_name $}
</a>
</li>
</ul>
</div>
</td>
</tr>
</table>

Advantages
● Clean split between server and client side
● Significantly cleaner, terser, easier to
understand client-side code
● Significant easier to improve UX
● Client- and server-side code can be
developed and tested independently
● Faster feature velocity

AngularJS + Horizon in Production

Client-side Rendering
“Full” dataset search
“Full” pagination Cache up to 1K records client-side

Real-time Data
Updates every 5s
Increased platform visibility
Every node instrumented

Historical Metrics
Up to 1 year of data
Convenient access
Increased platform visibility Every node instrumented

OpenStack Horizon
Contributing

Devstack and Contributing
● Devstack:
o “A documented shell script to build complete
OpenStack development environments.”
o http://devstack.org
● Contributing to Horizon:
– http://docs.openstack.org/developer/horizo
n/contributing.html

Thank You
David Lapsley
@devlaps, david.lapsley@metacloud.com

If this sounds interesting…
http://jobs.metacloud.com
We are hiring!

20141001 delapsley-oc-openstack-final

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