doc: Add USE_PYTHON3 to configuration guide
Change-Id: I8b6743c1dbdc00001691b2727bd0c344fb6ccd51
diff --git a/doc/source/configuration.rst b/doc/source/configuration.rst
index 46e50df..022e6ba 100644
--- a/doc/source/configuration.rst
+++ b/doc/source/configuration.rst
@@ -446,6 +446,16 @@
ADDITIONAL_VENV_PACKAGES="python-foo, python-bar"
+Use python3
+------------
+
+By default ``stack.sh`` uses python2 (the exact version set by the
+``PYTHON2_VERSION``). This can be overriden so devstack will run
+python3 (the exact version set by ``PYTHON3_VERSION``).
+
+ ::
+
+ USE_PYTHON3=True
A clean install every time
--------------------------