digraph G {
    node [ shape=box ]
#    rankdir=BT;

    label="CDN flows"

    subgraph cluster_user {
        label="Outside / in the Internet"
        user [ label="User\n(internal/customer)" color=pink ]
        client [ label="Web site User\n" color=blue ]
        operator [ label="CDN Operator\n" color=green ]
    }

    subgraph cluster_origin {
        label="Origin DC"
        origin [ label="Origin Node\nServing example.com"  ]
    }
    client->origin [ label="non-CDN access" style=dashed color=blue ]

    subgraph cluster_homedc {
        label="HomeDC"

        kubemaster [ label="Kubernetes master nodes" ]
        kubeworker [ label="Kubernetes worker nodes" ]

        subgraph cluster_kubernetes {
            label="Kubernetes Workload"

            api [ label="Tenant/OpsAPI" ]
            ui [ label="User Interface\nPost MVP" ]
            db [ label="Database" ]
            promhome [ label="Prometheus" ]
            grafana [ label="Grafana" ]
        }
    }
    kubemaster->kubeworker [ label="Controls" ]
    api->kubeworker [ label="Runs on" ]

    subgraph cluster_pops {
        label="PoP"

        servicenode [ label="Service Node" ]
        edgenode [ label="Edge nodes" ]
        delivery [ label="Delivery API" ]
        prompop [ label="Prometheus" ]
    }
    delivery->servicenode [ label="Runs on" ]

    user->ui [ label="A1. Create configuration" color=pink ]
    user->api [ label="A1. Create configuration" style=dashed color=pink ]
    ui->api [ label="A2. Create configuration" color=pink ]
    api->db [ label="A3. Store data" color=pink ]
    kubeworker->delivery [ label="A4. Trigger update" color=pink ]
    delivery->edgenode [ label="A5. Reconfigure" color=pink ]

    client->edgenode [ label="B1. Request data for example.com" color=blue ]
    edgenode->origin [ label="B2. Request data\n(If not cached)" color=blue]
    edgenode->client [ label="B3. Return data for example.com" weight=0.2 color=blue ]

    promhome->prompop [ label="C1. Pulls metrics" color=green ]
    operator->grafana [ label="C2. View monitoring data" color=green ]
    grafana->promhome [ label="C3. Gets data" color=green ]
    prompop->{edgenode,servicenode} [ label="Monitors" ]
    promhome->{api,db} [ label="Monitors" ]

}