Module 2: Abstracting Services using the App Services 3 Extension
=================================================================

In this Module, we will continue working with the BIG-IP REST interface.
However, we will now introduce F5 Declarative Interfaces built with the App
Services 3 Extension (AS3).

The AS3 Extension is built on top of the extensible, Node.js based iControl LX
framework and implemented a declarative, application-centric schema for
deploying Layer 4-7 Application Services on BIG-IP devices.

.. NOTE:: Previous versions of this class utilized an iApp Template named the
   App Services Integration iApp.  The AS3 extension is a replacement for the
   functionality provided by this iApp Template.

.. NOTE:: iControl LX extensions are **not** iApp Templates. The AS3 Extension
   does not use the TCL based iApp framework.  Additionally, AS3 does not use
   an Application Service Object (ASO).

When deploying services using AS3, we will use a declarative interface and JSON
based schema.  This *declaration* describes the desired end state of the
device. AS3 contains a TMOS independent parser that fully validates
declarations before any changes are made to the configuration of a BIG-IP
device.  Additionally, AS3 is:

- `Idempotent <https://whatis.techtarget.com/definition/idempotence>`_
- `Atomic <https://www.techopedia.com/definition/3466/atomic-operation>`_
- `Multi-Tenant <https://en.wikipedia.org/wiki/Multitenancy>`_
- `Supported by F5 <https://f5.com/support/support-policies>`_

For further information on the App Services 3 Extension see:

- **GitHub Repository:** https://github.com/F5Networks/f5-appsvcs-extension

- **Documentation:** https://clouddocs.f5.com/products/extensions/f5-appsvcs-extension/latest/

An overview of iControl LX can be found at 
https://clouddocs.f5.com/api/irules-lx/

.. NOTE:: This module requires the underlying network configuration that was
   completed in Module 1.  Additionally, **BIG-IP A** must be the **Active**
   node in the cluster.  When viewing the BIG-IP A GUI, it should say
   ``ONLINE (ACTIVE)`` in the upper left corner of the interface.

   You can learn more about clustering features in this video:

   .. raw:: html

      <p>  <iframe width="600" height="315" src="https://www.youtube.com/embed/RAQ1qaYnjZo" frameborder="0" gesture="media" allowfullscreen></iframe> </p>

   *Source: https://devcentral.f5.com/articles/lightboard-lessons-device-services-clustering-25575*

.. toctree::
   :maxdepth: 1
   :glob:

   lab*