.. highlight:: shell-session

Quick start
===========

These instructions are suitable for installing GWCelery for development and
testing on any machine.

To install
----------

.. important::
   GWCelery requires Python 3.6; it does not work with Python 3.7 right now.

   There is a `bug in the Celery 4.2.1`_ that makes it incompatible with Python
   3.7. It has already been fixed upstream, but it will continue to affect us
   `until Celery 4.3 is released`_.

The easiest way to install it is with ``venv`` and ``pip``::

    $ python -m venv --system-site-packages ~/gwcelery
    $ source ~/gwcelery/bin/activate
    $ pip install gwcelery

.. hint::
   **Note:** GWCelery requires a fairly new version of `setuptools`. If you get
   an error message that looks like this::

       pkg_resources.VersionConflict: (setuptools 0.9.8
       (/usr/lib/python2.7/site-packages),
       Requirement.parse('setuptools>=30.3.0'))

   then run ``pip install --upgrade setuptools`` and try again.

.. _`bug in the Celery 4.2.1`: https://github.com/celery/celery/pull/4852
.. _`until Celery 4.3 is released`: https://github.com/celery/celery/issues/5180

To test
-------

With ``setup.py``::

    $ python setup.py test

To start
--------

Before starting GWCelery, you need to authenticate for access to GraceDb and
LVAlert and make sure that you have a Redis server running. Once you have
completed those steps, you can start each of the GWCelery manually.

Authentication
~~~~~~~~~~~~~~

To authenticate for GraceDb, obtain grid credentials from the `LSC
DataGrid Client`_ by running ``ligo-proxy-init``::

    $ ligo-proxy-init albert.einstein

To authenticate for LVAlert, first complete the `LVAlert Account Activation`_
form once for each LVAlert server that you intend to use (generally you only
need "Playground" for development purposes). Make a note of the passwords and
store them in your ~/.netrc file with appropriate file permissions::

    $ echo > ~/.netrc
    $ chmod 0600 ~/.netrc
    $ echo machine lvalert.cgca.uwm.edu login albert.einstein password password-for-production >> ~/.netrc
    $ echo machine lvalert-playground.cgca.uwm.edu login albert.einstein password password-for-playground >> ~/.netrc
    $ echo machine lvalert-test.cgca.uwm.edu login albert.einstein password password-for-test >> ~/.netrc

.. _`LSC DataGrid Client`: https://www.lsc-group.phys.uwm.edu/lscdatagrid/doc/installclient.html
.. _`LVAlert Account Activation`: https://www.lsc-group.phys.uwm.edu/cgi-bin/jabber-acct.cgi

Redis
~~~~~

GWCelery requires a `Redis`_ database server for task bookkeeping. Your
operating system's package manager may be able to install, configure, and
automatically launch a suitable Redis server for you.

.. rubric:: Debian, Ubuntu, ``apt``

Debian or Ubuntu users can install and start Redis using ``apt-get``::

    $ sudo apt-get install redis

.. rubric:: macOS, `MacPorts`_

Mac users with MacPorts can install Redis using ``port install``::

    $ sudo port install redis

Use ``port load`` to start the server::

    $ sudo port load redis

.. rubric:: From source

If none of the above options are available, then you can follow the `Redis
Quick Start`_ instructions to build redis from source and start a server::

    $ wget http://download.redis.io/redis-stable.tar.gz
    $ tar xvzf redis-stable.tar.gz
    $ cd redis-stable
    $ make -j
    $ src/redis-server

Start GWCelery components manually
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

GWCelery itself consists of five :ref:`Celery workers <celery:guide-workers>`
and one `Flask`_ web application. Start them all by running each of the
following commands::

    $ gwcelery worker -l info -n gwcelery-worker -Q celery -B
    $ gwcelery worker -l info -n gwcelery-exttrig-worker -Q exttrig -c 1
    $ gwcelery worker -l info -n gwcelery-openmp-worker -Q openmp -c 1
    $ gwcelery worker -l info -n gwcelery-superevent-worker -Q superevent -c 1
    $ gwcelery worker -l info -n gwcelery-voevent-worker -Q voevent -P solo
    $ gwcelery flask run

.. hint::
   With these arguments, each of the commands above will run until you type
   Control-C. You may want to run each of them in a separate terminal, or in
   the background using `screen`_ or `nohup`_.

.. _`redis`: https://redis.io
.. _`MacPorts`: https://www.macports.org
.. _`Redis Quick Start`: https://redis.io/topics/quickstart
.. _`Flask`: http://flask.pocoo.org
.. _`screen`: https://linux.die.net/man/1/screen
.. _`nohup`: https://linux.die.net/man/1/nohup
