Review and clarify licence/notice information

[potiuk]

While reviewig the fix for #11544 I realised we might need to update (or better automate) our LICENSING information.

We currently Have NOTICE file in Airflow and a mixture of LICENSE + license directory.

NOTICE file here:

Apache Airflow
Copyright 2016-2019 The Apache Software Foundation

This product includes software developed at The Apache Software
Foundation (http://www.apache.org/).

=======================================================================

hue:
-----
This product contains a modified portion of 'Hue' developed by Cloudera, Inc.
(https://github.com/cloudera/hue/).

* Copyright 2009-2017 Cloudera Inc.

python-slugify:
---------------

* Copyright (c) Val Neekman @ Neekware Inc. http://neekware.com

python-nvd3:
------------

* Copyright (c) 2013 Arezqui Belaid <areski@gmail.com> and other contributors

But also, the LICENSE file contains mentioning 3rd party components and MIT:

============================================================================
   APACHE AIRFLOW SUBCOMPONENTS:

   The Apache Airflow project contains subcomponents with separate copyright
   notices and license terms. Your use of the source code for the these
   subcomponents is subject to the terms and conditions of the following
   licenses.

========================================================================
Third party Apache 2.0 licenses
========================================================================

The following components are provided under the Apache 2.0 License.
See project link for details. The text of each license is also included
at licenses/LICENSE-[project].txt.

    (ALv2 License) hue v4.3.0 (https://github.com/cloudera/hue/)
    (ALv2 License) jqclock v2.3.0 (https://github.com/JohnRDOrazio/jQuery-Clock-Plugin)
    (ALv2 License) bootstrap3-typeahead v4.0.2 (https://github.com/bassjobsen/Bootstrap-3-Typeahead)

========================================================================
MIT licenses
========================================================================

The following components are provided under the MIT License. See project link for details.
The text of each license is also included at licenses/LICENSE-[project].txt.

    (MIT License) jquery v3.4.1 (https://jquery.org/license/)
    (MIT License) dagre-d3 v0.6.4 (https://github.com/cpettitt/dagre-d3)
    (MIT License) bootstrap v3.2 (https://github.com/twbs/bootstrap/)
    (MIT License) d3-tip v0.9.1 (https://github.com/Caged/d3-tip)
    (MIT License) dataTables v1.10.20 (https://datatables.net)
    (MIT License) Bootstrap Toggle v2.2.2 (http://www.bootstraptoggle.com)
    (MIT License) normalize.css v3.0.2 (http://necolas.github.io/normalize.css/)
    (MIT License) ElasticMock v1.3.2 (https://github.com/vrcmarcos/elasticmock)
    (MIT License) MomentJS v2.24.0 (http://momentjs.com/)
    (MIT License) moment-strftime v0.5.0 (https://github.com/benjaminoakes/moment-strftime)
    (MIT License) python-slugify v4.0.0 (https://github.com/un33k/python-slugify)
    (MIT License) python-nvd3 v0.15.0 (https://github.com/areski/python-nvd3)
    (MIT License) eonasdan-bootstrap-datetimepicker v4.17.37 (https://github.com/eonasdan/bootstrap-datetimepicker/)

========================================================================
BSD 3-Clause licenses
========================================================================
The following components are provided under the BSD 3-Clause license. See project links for details.
The text of each license is also included at licenses/LICENSE-[project].txt.

    (BSD 3 License) d3 v5.15.0 (https://d3js.org)

But we also have the separate licenses directory where a number of licenses are placed:

LICENSE-bootstrap.txt
LICENSE-bootstrap3-typeahead.txt
LICENSE-d3-tip.txt
LICENSE-d3js.txt
LICENSE-dagre-d3.txt
LICENSE-datatables.txt
LICENSE-elasticmock.txt
LICENSE-eonasdan-bootstrap-datetimepicker.txt
LICENSE-flask-kerberos.txt
LICENSE-hue.txt
LICENSE-jqclock.txt
LICENSE-jquery.txt
LICENSE-moment.txt
LICENSE-moment-strftime.txt
LICENSE-normalize.txt
LICENSE-python-nvd3.txt
LICENSE-python-slugify.txt

I think we should just choose one way of reporting licences and (if possible) automate it.

[potiuk]

Happy to collaborate on that one @ashb @kaxil . I belive also @ryw wanted to get some clarity on those.

[potiuk]

BTW. I reviewed the existing licenced software and none of them apply for the providers so I left only generic Apache Licence information there, But we might want to do some additional check and automation there.

[ashb]

Fairly sure this style was what we had to do to graduate from incubation (we'll have to look back though the archives) so I don't think we can change

[potiuk]

Fine. I am just also wondering if some of those (slugify) has not changed since ?

[potiuk]

On top of that - I think there are at least two .json schema files in our code that have no licence we should make sure to run the licence checks/fixes before we prepare an RC1.

[ashb]

On top of that - I think there are at least two .json schema files in our code that have no licence we should make sure to run the licence checks/fixes before we prepare an RC1.

I think the json files we'll have to exclude -- there's no way of adding a comment to a JSON file, so we have no mechanism to add a license without hacks there.

[potiuk]

Ah yeah. Maybe as a description. We do some runtime checks involving the schema files currently.