Add a tool that allows visualizing the projects as a graph

This tool, when ran can create diagrams that show what
exactly the big-tent is and/or what the subprojects/deliverables
a project produces are.

For example, here is the way to create a output for ironic
and its deliverables:

$ python tools/universe_dot.py  reference/projects.yaml \
  ironic_universe.dot ironic;

$ neato -Tsvg ironic_universe.dot > ironic_universe.svg

Then view svg as is, or convert to png or other...

This requires pydot2 and pyyaml to be installed to work.

Change-Id: Idcd73f9e678e200d65eda4d1d54f1156fd18853b

requirements.txt

@@ -0,0 +1,5 @@
+# NOTE(harlowja): For graph generation tool.
+#
+# Not currently needed for anything else.
+pydot2>=1.0.32
+PyYAML>=3.1.0

tools/universe_dot.py

@@ -0,0 +1,141 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+#
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+#
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+A tool that will translate a projects.yaml file into a visualized graph.
+
+Usage: universe_dot.py <projects-file> <output-file> just-project? ...
+
+To run make sure pydot (or pydot2) is installed, as well as six and pyyaml.
+
+After these are installed run this like:
+
+$ python tools/universe_dot.py reference/projects.yaml \
+  ironic_universe.dot ironic;
+
+$ neato -Tsvg ironic_universe.dot > ironic_universe.svg
+
+Then open ironic_universe.svg in your favorite web browser.
+
+Or to create the whole openstack universe.
+
+$ python tools/universe_dot.py reference/projects.yaml os_universe.dot
+
+$ neato -Tsvg os_universe.dot > os_universe.svg
+
+Then open os_universe.svg in your favorite web browser.
+"""
+
+import sys
+import time
+
+if len(sys.argv) == 1:
+    print(__doc__.strip())
+    sys.exit(1)
+
+import pydot
+import six
+import yaml
+
+projects_file = sys.argv[1]
+output_dot_file = sys.argv[2]
+just_projects = set(sys.argv[3:])
+
+print("Reading projects from '%s'" % projects_file)
+with open(projects_file, 'rb') as fh:
+    projects = yaml.safe_load(fh)
+    project_names = sorted(six.iterkeys(projects))
+    if just_projects:
+        print("Restricting to just %s projects" % list(just_projects))
+        for project_name in list(project_names):
+            if project_name not in just_projects:
+                project_names.remove(project_name)
+    project_names = tuple(project_names)
+
+graph_nodes = {}
+start = time.time()
+print("Constructing nodes.")
+print("Please wait...")
+deliverable_node_attrs = {
+    'fontsize': '11',
+}
+project_node_attrs = {
+    'fontsize': '11',
+    'shape': 'diamond',
+}
+node_count = 0
+edges_needed = 0
+for project_name in project_names:
+    node = pydot.Node(name=project_name, **project_node_attrs)
+    node_count += 1
+    graph_nodes[project_name] = node
+    deliverables = projects[project_name].get('deliverables', [])
+    deliverable_names = sorted(six.iterkeys(deliverables))
+    for deliverable_name in deliverable_names:
+        edges_needed += 1
+        node_path = "%s/%s" % (project_name, deliverable_name)
+        if deliverable_name == project_name:
+            # Avoid creating a self-link, since its actually not, avoid
+            # this by creating a node with a hidden name, and a label that
+            # is its actual name...
+            node_deliverable_node_attrs = dict(deliverable_node_attrs)
+            node_deliverable_node_attrs['name'] = '__%s' % deliverable_name
+            node_deliverable_node_attrs['label'] = deliverable_name
+        else:
+            node_deliverable_node_attrs = dict(deliverable_node_attrs)
+            node_deliverable_node_attrs['name'] = deliverable_name
+        node = pydot.Node(**node_deliverable_node_attrs)
+        graph_nodes[node_path] = node
+        node_count += 1
+
+print("Inserting %s nodes and %s edges into"
+      " a new graph." % (node_count, edges_needed))
+print("Please wait...")
+if just_projects:
+    nice_names = [name.title() for name in sorted(just_projects)]
+    graph_name = '%s Universe' % (" and ".join(nice_names))
+else:
+    graph_name = 'OpenStack Universe'
+graph_kwargs = {
+    'rankdir': 'LR',
+    'nodesep': '0.25',
+    'overlap': 'false',
+    'ranksep': '0.5',
+    'splines': 'true',
+    'ordering': 'in',
+    'graph_name': graph_name,
+}
+graph = pydot.Graph(**graph_kwargs)
+for project_name in project_names:
+    print("  Inserting nodes for '%s'" % project_name)
+    node = graph_nodes[project_name]
+    graph.add_node(node)
+    deliverables = projects[project_name].get('deliverables', [])
+    deliverable_names = sorted(six.iterkeys(deliverables))
+    for deliverable_name in deliverable_names:
+        print("    Inserting node for '%s'" % deliverable_name)
+        node_path = "%s/%s" % (project_name, deliverable_name)
+        deliverable_node = graph_nodes[node_path]
+        graph.add_node(deliverable_node)
+        print("    Inserting edge for '%s' -> '%s'"
+              % (project_name, deliverable_name))
+        graph.add_edge(pydot.Edge(node, deliverable_node,
+                                  style='dotted'))
+end = time.time()
+print("Finished in %0.2f seconds" % (end - start))
+
+print("Writing graph to '%s'" % output_dot_file)
+with open(output_dot_file, "wb") as fh:
+    fh.write(graph.to_string())