digraph "index" {

subgraph "cluster/dev" { label="Dev"
 "plan" [label="Plan"]
 "code" [label="Code"]
 "build" [label="Build"]
 "test" [label="Test"]
}

subgraph "cluster/ops" { label="Ops"
 "release" [label="Release"]
 "deploy" [label="Deploy"]
 "operate" [label="Operate"]
 "monitor" [label="Monitor"]
}

}