python: ovs: flowviz: Add datapath graph format.

Graph view leverages the TreeFlow hierarchy and uses graphviz library to
build a visual graph of the datapath tree.

Conntrack zones are shown in random colors to help visualize connection
tracking interdependencies.

An html flag builds an HTML page with both the html flows and the graph
(in svg) that enables navigation.

Examples:
$ ovs-appctl dpctl/dump-flows -m | ovs-flowviz datapath graph | dot
-Tpng -o graph.png
$ ovs-appctl dpctl/dump-flows -m | ovs-flowviz datapath graph --html >
flows.html

Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

python/setup.py.template

@@ -106,7 +106,7 @@ setup_args = dict(
                     'dns': ['unbound'],
                     'flow': flow_extras_require,
                     'flowviz':
-                        [*flow_extras_require, 'click', 'rich'],
+                        [*flow_extras_require, 'click', 'rich', 'graphviz'],
                     },
     scripts=["ovs/flowviz/ovs-flowviz"],
     data_files=["ovs/flowviz/ovs-flowviz.conf"],