Lab 1 - iRules LX Streaming
---------------------------

Creating and Implementing a Streaming LX Plugin
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In this lab we will be loading an LX plugin in streaming mode. To keep
the lab simple, we will only be loading a plugin that will print the
client data to hexdump format in the log files.


Review the LX Workspace and Install NPM package
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The first thing we need to do is view the LX Workspace. On the desktop,
navigate over to the LX workspaces menu in the tab located at *Local
Traffic > iRules > LX Workspaces*. Then click the workspace named
*ilxlab4\_stream*. You should see an extension named hexdump, then click
on the *index.js* file. Also, we should note that you will not see a TCL
rule in the workspace.

Just for reference, here is the Node.js code below:

.. code-block:: javascript
   :linenos:

   'use strict';
   // Hexdump all client data to stdout on L4 virtual server
   var f5 = require('f5-nodejs');
   var plugin = new f5.ILXPlugin();
   var hexy = require('hexy');

   // Register a listener for the client ILXPlugin "connect" event
   plugin.on('connect', function(flow) {
     // Register a listener for the ILXStream "data" event
     flow.client.on('data', function (data) {
       console.log(hexy.hexy(data)); //Print the client data to STDOUT
       flow.server.write(data);  //Pass the client data to the server stream
     })

     // Create event listeners for error events
     flow.client.on('error', function(errorText) {
       console.log('client error event: ' + errorText);
     });
     flow.server.on('error', function(errorText) {
       console.log('server error event: ' + errorText);
     });
     flow.on('error', function(errorText) {
       console.log('flow error event: ' + errorText);
     });
   });

   // Tell TMM not to send data from server to Node
   var options = new f5.ILXPluginOptions();
   options.handleServerData = false;
   plugin.start(options); //Start the plugin in streaming mode

As you can see from the code above we are loading the hexy package for
doing the hexdumps of the buffer chunk. Therefore, we need to install
this package into the workspace. To do this you will need to SSH to the
BIG-IP and execute the following commands from the BASH prompt:

.. code-block:: console

   # cd /var/ilx/workspaces/Common/ilxlab4_stream/extensions/hexdump/
   # npm install --save hexy

Create the LX Plugin
^^^^^^^^^^^^^^^^^^^^

With our code already in a workspace, you will need to navigate over to
the LX Plugins menu in the tab located at *Local Traffic > iRules > LX
Plugins*. Click the *Create* button, name the plugin
*ilxlab4\_stream\_pl*, select the *ilxlab4\_stream* workspace and click
finish to save the changes.

We still need to configure a few more things so once you are back to the
LX Plugin list, click on the *ilxlab4\_stream\_pl* plugin and then click
on the *hexdump* extension. Change the following settings:

+---------------------+-------------+----------------------------------------------------+
| Setting             | New Value   | Reason                                             |
+=====================+=============+====================================================+
| Concurrency Mode    | Single      | Keep logs for all connections in a single file.    |
+---------------------+-------------+----------------------------------------------------+
| iRules LX Logging   | Checked     | Will make extension send logs to dedicated file.   |
+---------------------+-------------+----------------------------------------------------+

Create the iRules LX Profile
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Since iRules LX Streaming does not require the use of TCL iRules, we
need a method to associate an LX Plugin to a virtual server. That is
done with an iRules LX profile. To create a new iRules LX profile,
navigate to the menu *Local Traffic > Profiles > Other > iRules LX* and
click the + sign.

Name the new profile *ilxlab4\_stream\_profile*, select the
*ilxlab4\_stream\_pl* LX Plugin and click finish to save the changes.

Assign the iRules LX Profile to Virtual Servers
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Now we need to attach our profile to a virtual server. Go into the
virtual server *ilxlab4\_stream\_vs* main configuration “properties”
window (not the resources tab), then expand the Configuration menu
to the advanced setting and you will see the iRules LX Profile setting
as shown here:

|image18|

Select the *ilxlab4\_stream \_profile* then click update at the bottom
to save the changes.

Test the ILX Streaming Plugin
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Now we should be able to see the hexdumps in the log file. First, in an
SSH session with the BIG-IP, tail the log file of the plugin with the
following command:

``# tail -f  /var/log/ilx/Common/ilxlab4_stream_pl.hexdump``

Then refresh the page in the browser (URL http://10.0.0.23/ilxlab4stream)
and you should see output like this in the SSH terminal:

|image19|

Create and Implement an HTTP server LX Plugin
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In this lab exercise, we will use the LX plugin as an HTTP server. The
virtual server that we will use this LX Plugin is the
*ilxlab4\_http\_vs* (10.0.0.24) virtual server which does not have a pool attached
to it. This VS does not have an HTTP profile associated with it as use
of the iRules LX HTTP server requires this configuration.

Review the LX Workspace
^^^^^^^^^^^^^^^^^^^^^^^

Go to the LX workspace named *ilxlab4\_http*, click on the extension
folder named *http\_server* and click on the *index.js* file. You should
see code that looks like this:

.. code-block:: javascript

   'use strict';
   // Use iRules LX as simple HTTP server
   var f5 = require('f5-nodejs');

   // Create the HTTP request callback function
   function httpRequestCallback(req, res) {
     var msg =  '<html><body><h1>ILX HTTP Server</h1>';
     msg += '<p>Welcome client "' + req.client.remoteAddress + '". ';
     msg += 'Your HTTP method is ' + req.method + '.</p>';
     msg += '</body></html>';
     // Set HTTP respond, send reply and close connection.
     res.writeHead(200, {'Content-Type': 'text/html'});
     res.end(msg);
   }

   var plugin = new f5.ILXPlugin();
   plugin.startHttpServer(httpRequestCallback);

Create the LX Plugin, Profile and Attach to Virtual Server
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

With our code already in a workspace, all we need to do is create our LX
Plugin and iRules LX profile, and attach the profile to the virtual
server. Name your LX Plugin *ilxlab4\_http\_pl*. Create the iRules LX
profile with the name of *ilxlab4\_http\_profile* and attach it to the
*ilxlab4\_http\_vs* virtual server.

Test the ILX HTTP Plugin
^^^^^^^^^^^^^^^^^^^^^^^^

In your web browser’s 2\ :sup:`nd` tab type in the URL http://10.0.0.24.
You should see a web page like this –

|image20|

.. |image18| image:: /_static/class3/image19.png
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.. |image19| image:: /_static/class3/image20.png
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.. |image20| image:: /_static/class3/image21.png
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