Setting up a Node with a Single NIC
===================================

Installing the STN Daemon
-------------------------

The STN (Steal the NIC) daemon must be installed on every node in the
cluster that has only one NIC. The STN daemon installation(*) should be
performed before deployment of the Contiv-VPP plugin.

\* Docker daemon must be present when installing STN. Also, Docker must
be configured to allow shared mount. On CentOS, this may not be the case
by default. You can enable it by following the instructions at
https://docs.portworx.com/knowledgebase/shared-mount-propagation.html.

Run as root (not using sudo):

::

   bash <(curl -s https://raw.githubusercontent.com/contiv/vpp/master/k8s/stn-install.sh)

The install script should output the following:

::

   Installing Contiv STN daemon.
   Starting contiv-stn Docker container:
   550334308f85f05b2690f5cfb5dd945bd9c501ab9d074231f15c14d7098ef212

Check that the STN daemon is running:

::

   docker ps -a
   CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
   550334308f85        contivvpp/stn       "/stn"              33 seconds ago      Up 33 seconds                           contiv-stn

Check that the STN daemon is operational:

::

   docker logs contiv-stn

The expected logs would look like the following excerpt:

::

   2018/02/23 10:08:34 Starting the STN GRPC server at port 50051

For more details, please read the Go documentation for
`contiv-stn <https://github.com/contiv/vpp/blob/master/cmd/contiv-stn/doc.go>`__
and
`contiv-init <https://github.com/contiv/vpp/blob/master/cmd/contiv-init/doc.go>`__.

Creating a VPP Interface Configuration
--------------------------------------

Create the VPP configuration for the hardware interface as described
`here <https://github.com/contiv/vpp/blob/master/docs/VPP_CONFIG.md#single-nic-configuration>`__.

Configuring STN in Contiv-VPP K8s Deployment Files
--------------------------------------------------

The STN feature is disabled by default. It needs to be enabled either
globally, or individually for every node in the cluster.

Global Configuration:
~~~~~~~~~~~~~~~~~~~~~

Global configuration is used in homogeneous environments where all nodes
in a given cluster have the same hardware configuration, for example
only a single Network Adapter. To enable the STN feature globally, put
the ``StealFirstNIC: True`` stanza into the [``contiv-vpp.yaml``][1]
deployment file, for example:

::

   data:
     contiv.yaml: |-
       TCPstackDisabled: true
       ...
       StealFirstNIC: True
       ...
       IPAMConfig:

Setting ``StealFirstNIC`` to ``True`` will tell the STN Daemon on every
node in the cluster to steal the first NIC from the kernel and assign it
to VPP. Note that the Network Adapters on different nodes do not need to
be of the same type. You still need to create the respective vswitch
configurations on every node in the cluster, as shown
[above](#creating-a-vpp-interface-configuration).

Individual Configuration:
~~~~~~~~~~~~~~~~~~~~~~~~~

Individual configuration is used in heterogeneous environments where
each node in a given cluster may be configured differently. To enable
the STN feature for a specific node in the cluster, put the following
stanza into its Node Configuration in the [``contiv-vpp.yaml``][1]
deployment file, for example:

::

   ...
       NodeConfig:
       - NodeName: "ubuntu-1"
         StealInterface: "enp0s8"
       - NodeName: "ubuntu-2"
         StealInterface: "enp0s8"
   ...

Note that you still have to create the vswitch configuration on the node
as shown `here <#creating-a-vpp-interface-configuration>`__.

Uninstalling the STN Daemon
---------------------------

Run as root (not using sudo):

::

   bash <(curl -s https://raw.githubusercontent.com/contiv/vpp/master/k8s/stn-install.sh) --uninstall

The install script should output the following:

::

   Uninstalling Contiv STN daemon.
   Stopping contiv-stn Docker container:
   contiv-stn
   contiv-stn
   contiv-stn

Make sure that the STN daemon has been uninstalled:

::

   docker ps -q -f name=contiv-stn

No containers should be listed.