========================= Tested Runtimes for Train ========================= It is the policy that each OpenStack release cycle will target the currently available runtimes on the :ref:`LTS or stable distributions ` at the start of a development cycle. At the start of the Train development cycle, the current versions are: * Ubuntu 18.04 * CentOS 7 * openSUSE Leap 15 Python Runtime for Train ======================== Based on the available Python runtimes for the supported Linux distributions, all Python-based projects must target and test against, at a minimum: * Python 2.7 * Python 3.6 * Python 3.7 More details on Python requirements can be found in :ref:`pti-python`. Node.js Runtime for Train ========================= Based on the availible versions of Node.js supported in our :ref:`LTS or stable distributions ` all JavaScript testing should target: * Node.js 10 More details on Javascript requirements can be found in :ref:`pti-javascript`. Golang Runtime for Train ======================== At this time, there are still frequent releases of Go with a wide variety of distribution packaged versions. Given the current state of Go support and the number of projects within OpenStack using Go, no formal version declaration is being made at this time. More details on Go requirements can be found in :ref:`pti-golang`.