=====================
Before your first job
=====================


Before your **first attempt to submit a job** to PSMN's clusters, you need to generate an **internal** SSH keys pair:


Generate internal PSMN SSH keys
===============================

.. IMPORTANT:: PSMN :term:`SSH` keys

    This step generates a :term:`SSH` keys pair which is needed for your work on PSMN servers: for instance, job management, which are automated process **on your behalf**, needs an automated authentication.

    These keys will be generated **without passphrase**, therefore they **MUST NOT** leave PSMN or be used for anything else: they basically provide no strong authentication.


So, the first time you connect by ssh to ``allo-psmn``, follow these instructions:

.. code-block:: bash

    ssh-keygen

To the question:

.. code-block:: bash

    Generating public/private rsa key pair.
    Enter file in which to save the key (/home/your_login/.ssh/id_rsa):

hit ENTER ⏎ (default answer).

.. note::
    New default parameters of :term:`SSH` may generate a ``ed25519`` key type. Replace ``.rsa`` by ``.ed25519`` in next parts of this documentation.

To the questions:

.. code-block:: bash

    Enter passphrase (empty for no passphrase):

and

.. code-block:: bash

    Enter same passphrase again:

hit ENTER ⏎ (default answer) again.

Then, create the file ``~/.ssh/authorized_keys`` file by  typing:

.. code-block:: bash

    touch ~/.ssh/authorized_keys

and add (``>>``) your PSMN public SSH key (``id_rsa.pub``) to the ``~/.ssh/authorized_keys`` file:

.. code-block:: bash

    cat .ssh/id_rsa.pub >> ~/.ssh/authorized_keys