[NSMCon] Use-case: Packet filter with two external gateways

[michaelspedersen]

Use-case is a variation of the existing external packet filter example.

                           Kubernetes Worker Node                                     External Server
+--------------------------------------------------------------------------+        +------------------+
|                                                                          |        |                  |
   +--------+
   |        |                                                 +---------+              +------------+
   | Kernel |                                    10.60.3.0/24 | Ext.    | 10.60.1.0/24 | Ext. IF    |
   | Client +-------+                           +-------------> Gateway +--------------+ 10.60.1.10 |
   |        |       |                           |             |         |              |            |
   +--------+       |       +---------------+   |             +---------+              +------------+
                    +------->               +---+
              10.60.4.0/24  | Packet Filter |
                    +------->               +---+
   +--------+       |       +---------------+   |             +---------+              +------------+
   |        |       |                           |             | Ext.    |              | Ext. IF    |
   |  VPP   +-------+                           +-------------> Gateway +--------------+ 10.60.0.10 |
   | Client |                                    10.60.2.0/24 |         | 10.60.0.0/24 |            |
   |        |                                                 +---------+              +------------+
   +--------+

TODO:

• [x] Create Helm chart for deployment
• [x] Test with external server
• [x] Create README