.. _use_console:

Connecting to the configuration database
========================================

The SDP can be controlled by directly interacting with its
Configuration Database (see :ref:`design_components`).
A CLI was developed to do that, which can be accessed via the ``console`` pod.

Details about the existing commands of the ``ska-sdp`` utility can be found in the
:external+ska-sdp-config:doc:`CLI to interact with SDP <cli>`
section in the SDP Configuration Library documentation.

.. warning::

    The following is not recommended for non-developers.
    Please follow the instructions in :ref:`access_tango_interface` to work with SDP.

Start a shell in the console pod by running:

.. code-block:: console

    $ kubectl exec -it ska-sdp-console-0 -n <control-namespace> -- bash

This will allow you to use the ``ska-sdp`` CLI:

.. code-block:: console

    # ska-sdp list -a
    Keys with prefix /:
    /lmc/controller
    /lmc/subarray/01
    /script/batch:test-batch:0.3.0
    ...

Which shows that the configuration DB contains the state of the Tango devices and
the processing script definitions.


Starting a processing script
----------------------------

Next, we can add a processing block to the configuration:

.. code-block:: console

    # ska-sdp create pb --script <script-kind>:<script-name>:<script-version>

For example

.. code-block:: console

    # ska-sdp create pb --script batch:test-dask:1.0.0
    Processing block created with pb_id: pb-sdpcli-20221011-00000

The processing block is created with the ``/pb`` prefix in the
configuration:

.. code-block:: console

    # ska-sdp list -v pb
    Keys with prefix /pb:
    /pb/pb-sdpcli-20221011-00000 = {
      "dependencies": [],
      "eb_id": null,
      "parameters": {},
      "pb_id": "pb-sdpcli-20221011-00000",
      "script": {
        "kind": "batch",
        "name": "test-dask",
        "version": "1.0.0"
      }
    }
    /pb/pb-sdpcli-20221011-00000/owner = {
      "command": [
        "test_dask.py"
      ],
      "hostname": "proc-pb-sdpcli-20221011-00000-script--1-qqvgw",
      "pid": 1
    }
    /pb/pb-sdpcli-20221011-00000/state = {
      "deployments": {
        "proc-pb-sdpcli-20221011-00000-dask-1": "RUNNING",
        "proc-pb-sdpcli-20221011-00000-dask-2": "RUNNING"
      },
      "last_updated": "2022-10-11 08:20:34",
      "resources_available": true,
      "status": "RUNNING"
    }

The processing block is detected by the processing controller which deploys the
script. The script in turn deploys the execution engines (in this case, Dask).

The deployments are requested by creating entries with ``/deploy`` prefix in
the configuration database, where they are detected by the Helm deployer
which actually makes the deployments:

.. code-block:: console

    # ska-sdp list -v deploy
    Keys with prefix /deploy:
    /deploy/proc-pb-sdpcli-20221011-00000-dask-1 = {
      "args": {
        "chart": "dask",
        "values": {
          "image": "artefact.skao.int/ska-sdp-script-test-dask:0.3.0",
          "worker.replicas": 2
        }
      },
      "dpl_id": "proc-pb-sdpcli-20221011-00000-dask-1",
      "kind": "helm"
    }
    /deploy/proc-pb-sdpcli-20221011-00000-dask-1/state = {
      "pods": {
        "proc-pb-sdpcli-20221011-00000-dask-1-scheduler-7d6f5f9749-vr6dw": "Running",
        "proc-pb-sdpcli-20221011-00000-dask-1-worker-5744899988-hmr5q": "Running",
        "proc-pb-sdpcli-20221011-00000-dask-1-worker-5744899988-sqnf6": "Running"
      }
    }
    /deploy/proc-pb-sdpcli-20221011-00000-dask-2 = {
      "args": {
        "chart": "dask",
        "values": {
          "image": "artefact.skao.int/ska-sdp-script-test-dask:0.3.0",
          "worker.replicas": 2
        }
      },
      "dpl_id": "proc-pb-sdpcli-20221011-00000-dask-2",
      "kind": "helm"
    }
    /deploy/proc-pb-sdpcli-20221011-00000-dask-2/state = {
      "pods": {
        "proc-pb-sdpcli-20221011-00000-dask-2-scheduler-65cc58cf4f-8bm9r": "Running",
        "proc-pb-sdpcli-20221011-00000-dask-2-worker-79694dbf85-j7nfb": "Running",
        "proc-pb-sdpcli-20221011-00000-dask-2-worker-79694dbf85-njw6c": "Running"
      }
    }
    /deploy/proc-pb-sdpcli-20221011-00000-script = {
      "args": {
        "chart": "script",
        "values": {
          "env": [
            {
              "name": "SDP_CONFIG_HOST",
              "value": "ska-sdp-etcd-client.dp-orca"
            },
            {
              "name": "SDP_HELM_NAMESPACE",
              "value": "dp-orca-p"
            },
            {
              "name": "SDP_PB_ID",
              "value": "pb-sdpcli-20221011-00000"
            }
          ],
          "image": "artefact.skao.int/ska-sdp-script-test-dask:0.3.0"
        }
      },
      "dpl_id": "proc-pb-sdpcli-20221011-00000-script",
      "kind": "helm"
    }
    /deploy/proc-pb-sdpcli-20221011-00000-script/state = {
      "pods": {
        "proc-pb-sdpcli-20221011-00000-script--1-r4p9c": "Running"
      }
    }

The deployments associated with the processing block have been created
in the ``<processing-namespace>``. You can list the running pods using kubectl
on the host (exit the console pod):

.. code-block:: console

    $ kubectl get pod -n <processing-namespace>
    NAME                                                              READY   STATUS    RESTARTS   AGE
    proc-pb-sdpcli-20221011-00000-dask-1-scheduler-7d6f5f9749-vr6dw   1/1     Running     0          9s
    proc-pb-sdpcli-20221011-00000-dask-1-worker-5744899988-hmr5q      1/1     Running     0          9s
    proc-pb-sdpcli-20221011-00000-dask-1-worker-5744899988-sqnf6      1/1     Running     0          9s
    proc-pb-sdpcli-20221011-00000-dask-2-scheduler-65cc58cf4f-8bm9r   1/1     Running     0          10s
    proc-pb-sdpcli-20221011-00000-dask-2-worker-79694dbf85-j7nfb      1/1     Running     0          10s
    proc-pb-sdpcli-20221011-00000-dask-2-worker-79694dbf85-njw6c      1/1     Running     0          10s
    proc-pb-sdpcli-20221011-00000-script--1-r4p9c                     1/1     Running     0          14s

Cleaning up
-----------

Finally, let us remove the processing block from the configuration DB:

.. code-block:: console

    # ska-sdp delete pb pb-sdpcli-20221011-00000
    /pb/pb-sdpcli-20221011-00000
    /pb/pb-sdpcli-20221011-00000/state
    Deleted above keys with prefix /pb/pb-sdpcli-20221011-00000.

If you re-run the commands from the last section you will notice that
this correctly causes all changes to the cluster configuration to be
undone as well.