Kubernetes
==========

This section describes the Kubernetes deployment of PPC Robot - requirements for the cluster, node taints etc.

Kubernetes Version
------------------

PPC Robot should be run on Kubernetes 1.10 or newer. All resource types and APIs must be available in the 1.10.


Node Types and Labels
---------------------

The following node labels are used for pod scheduling:

=========================================================== ======================================================
Label                                                       Required by
=========================================================== ======================================================
nodes.ppc-robot.net/db                                      PostgreSQL database
nodes.ppc-robot.net/redis                                   Redis
nodes.ppc-robot.net/web                                     Web Interface
nodes.ppc-robot.net/scheduler                               Scheduler
nodes.ppc-robot.net/worker-system                           System tasks worker
nodes.ppc-robot.net/worker-cluster                          Cluster management worker
nodes.ppc-robot.net/worker                                  Generic reports worker
nodes.ppc-robot.net/worker-url-check                        URL Checkers worker
=========================================================== ======================================================

Values of the label should be set to ``true``, however, only existence of such label is checked at the moment.


Deployment: Development Cluster
-------------------------------

Before you begin, you have to add labels to corresponding nodes:

    .. code-block:: bash

        kubectl label nodes <node> nodes.ppc-robot.net/db=true
        kubectl label nodes <node> nodes.ppc-robot.net/redis=true
        kubectl label nodes <node> nodes.ppc-robot.net/web=true
        kubectl label nodes <node> nodes.ppc-robot.net/scheduler=true
        kubectl label nodes <node> nodes.ppc-robot.net/rate-limiter=true
        kubectl label nodes <node> nodes.ppc-robot.net/worker-system=true
        kubectl label nodes <node> nodes.ppc-robot.net/worker-cluster=true
        kubectl label nodes <node> nodes.ppc-robot.net/worker=true
        kubectl label nodes <node> nodes.ppc-robot.net/worker-url-check=true

To deploy PPC Robot in development, take the following steps (cd to the `kubernetes` directory first):

1. Create SSD volume type and prepare Persistent Volumes:

    .. code-block:: bash

        kubectl apply -f development/ssd-storage-class.yml -f development/ssd-volumes.yml

2. Create necessary secrets and configmaps (update the configmaps/secrets if necessary):

    .. code-block:: bash

        bash create-configmaps.sh
        bash create-secrets.sh

3. Deploy PostgreSQL and Redis:

    .. code-block:: bash

        kubectl apply -f postgresql.yml -f redis.yml

4. Create database and user for ppc_robot:

    .. code-block:: bash

        bash development/create-database.sh

5. Apply development configuration for PPC Robot:

    .. code-block:: bash

        kubectl apply -f development/ppc-robot-config.yml

6. Deploy all containers and pods (requires the project to be installed on the machine):

    .. code-block:: bash

        fab k8s_deploy_resources


**Enabling access to the web UI:** Add the following service that will bind the web UI to NodePort:

.. code-block:: bash

    kubectl apply -f development/ppc-robot-web-nodeport.yml

Get the port on which the service was bound using the following command:

.. code-block:: bash

    $ kubectl describe services/ppc-robot-web-nodeport
    Name:                     ppc-robot-web-node-port
    Namespace:                default
    ...
    NodePort:                 <unset>  31830/TCP
    ...