On 2019-02-04 14:42:04 +0100 (+0100), Ilya Shakhat wrote:

I am experimenting with automatic verification of code licenses of OpenStack projects and see that one of Rally dependencies has GPL3 license [...]

To start off, it looks like the license for morph is already known to the Rally developers, based on the inline comment for it at https://git.openstack.org/cgit/openstack/rally/tree/requirements.txt?id=3625... (so hopefully this is no real surprise). The source of truth for our licensing policies, as far as projects governed by the OpenStack Technical Committee are concerned (which openstack/rally is), can be found here: https://governance.openstack.org/tc/reference/licensing.html It has a carve out for "tools that are run with or on OpenStack projects only during validation or testing phases of development" which "may be licensed under any OSI-approved license" and since the README.rst for Rally states it's a "tool & framework that allows one to write simple plugins and combine them in complex tests scenarios that allows to perform all kinds of testing" it probably meets those criteria. As for concern that a Python application which imports another Python library at runtime inherits its license and so becomes derivative of that work, that has been the subject of much speculation. In particular, whether a Python import counts as "dynamic linking" in GPL 3.0 section 1 is debatable: https://bytes.com/topic/python/answers/41019-python-gpl https://opensource.stackexchange.com/questions/1487/how-does-the-gpls-linkin... https://softwareengineering.stackexchange.com/questions/87446/using-a-gplv3-... https://stackoverflow.com/questions/40492518/is-an-import-in-python-consider... I'm most definitely not a lawyer, but from what I've been able to piece together it's the combination of rally+morph which potentially becomes GPLv3-licensed when distributed, not the openstack/rally source code itself. This is really more of a topic for the legal-discuss mailing list, however, so I am cross-posting my reply there for completeness. To readers only of the legal-discuss ML, the original post can be found archived here: http://lists.openstack.org/pipermail/openstack-discuss/2019-February/002356.... -- Jeremy Stanley