Add a venv that can generate/write/update the states diagram

Instead of requiring manual understanding of how to generate
the states diagram, add an explicit virtualenv that can be
used to create and generate that docs diagram (and replace the
existing file with it).

Change-Id: I1738da9bf08bfda9b9be01489e8456569a31709e

2 files changed, 5 insertions, 2 deletions

diff --git a/tools/states_to_dot.py b/tools/states_to_dot.py
index 4fa76fdcf..2104a095c 100755
--- a/tools/states_to_dot.py
+++ b/tools/states_to_dot.py
@@ -22,8 +22,6 @@ top_dir = os.path.abspath(os.path.join(os.path.dirname(__file__),
                                        os.pardir))
 sys.path.insert(0, top_dir)
 
-# To get this installed you may have to follow:
-# https://code.google.com/p/pydot/issues/detail?id=93 (until fixed).
 import pydot
 
 from ironic.common import states
diff --git a/tox.ini b/tox.ini
index 5b83d7f5a..f4612cd0a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,6 +18,11 @@ commands =
 [tox:jenkins]
 downloadcache = ~/cache/pip
 
+[testenv:genstates]
+deps = {[testenv]deps}
+    pydot2
+commands = {toxinidir}/tools/states_to_dot.py -f {toxinidir}/doc/source/images/states.png
+
 [testenv:pep8]
 commands =
   flake8 {posargs}