Nested directed subgraphs - graphviz

Question

I'm trying to obtain nested subgraphs in graphviz.
Graphviz version is 2.38.0 (20140413.2041)
Here is the code:
digraph G {
subgraph cluster_win {
style=filled;
color=lightgrey;
label = "Windows"
subgraph extra_enabled {
fillcolor = "#EDF1F2";
color = "#028d35";
label="Subdirectory extra included";
node [style=filled,color=white];
config_debug1 [label = "Configure Debug"];
config_release1 [label = "Configure Release"];
build_debug1 [label = "Build"];
build_release1 [label = "Build"];
config_debug1 -> build_debug1;
config_release1 -> build_release1;
shape=rect;
style=rounded;
}
subgraph extra_disabled {
label = "Subdirectory extra excluded";
config_debug2 [label = "Configure Debug"];
config_release2 [label = "Configure Release"];
build_debug2 [label = "Build"];
build_release2 [label = "Build"];
config_debug2 -> build_debug2;
config_release2 -> build_release2;
}
checkout [style=filled, color=white];
checkout -> extra_enabled;
checkout -> extra_disabled;
}
start -> checkout;
start [label="git push"; shape=Mdiamond];
}
And this is the result.
Graphviz draws two ordinary nodes "extra_enabled" and "extra_disabled". However, I want them to be subgraphs, containing nodes "Configure Release", "Configure Debug", "Build" and another "Build".
How can I fix it?

Answer 1

You need to do two things:
Connect nodes only, you cannot connect to a cluster
Cluster names need to be prefixed by cluster_
Applying this to your code
digraph G {
subgraph cluster_win {
style=filled;
color=lightgrey;
label = "Windows "
subgraph cluster_extra_enabled {
fillcolor = "#EDF1F2";
color = "#028d35";
label="Subdirectory extra included";
node [style=filled,color=white];
config_debug1 [label = "Configure Debug"];
config_release1 [label = "Configure Release"];
build_debug1 [label = "Build"];
build_release1 [label = "Build"];
config_debug1 -> build_debug1;
config_release1 -> build_release1;
shape=rect;
style=rounded;
}
subgraph cluster_extra_disabled {
label = "Subdirectory extra excluded";
config_debug2 [label = "Configure Debug"];
config_release2 [label = "Configure Release"];
build_debug2 [label = "Build"];
build_release2 [label = "Build"];
config_debug2 -> build_debug2;
config_release2 -> build_release2;
}
checkout [style=filled, color=white];
checkout -> config_debug1;
checkout -> config_release2;
}
start -> checkout;
start [label="git push"; shape=Mdiamond];
}
I get
which is probably close to what you want. Note that I have added a few spaces to the label "Windows " to get it out of the way of the arrow. You could also use labeljust. There are also ways to make the edge end at the boundary of the cluster, but that would have needed a lot more editing on my part which I was not sure you want it.

Answer 2

I just wanted to append to the answer that vaettchen added. While it is correct that you cannot directly connect edges to clusters, edges must travel between nodes, there is a way to do so visually with lhead and ltail.
You can do the following:
node1 -> node2 [lhead=cluster_name_1, ltail=cluster_name_2]
Which will cut the connectors off at the limit of the cluster to connect clusters, this is just visual and is logged as a node connection, but it is a nicer way to visually display connections between whole clusters.