Private network¶

VMs making up raya talk to each other via a dedicated private network which is declared in network.tf. The VMs are all attached to the same subnet located in the eu-central zone, meaning server locations are restricted to hel1 (Helsinki), nbg1 (Nuremberg), and fsn1 (Falkenstein).

Traffic inside a subnet is not billed by Hetzner, and it means node-to-node communication stays off the public Internet.

Addressing¶

Addresses inside nodes are assigned by hand in network.tf, so they follow a convention rather than a mechanism. 10.0.1.1 to 10.0.1.9 are reserved for Hetzner and use cases that may arise at a later date. The control plane takes 10.0.1.10, and agents start at 10.0.1.20.

Topology¶

The current topology is as follows (location clusters are shown to highlight the impact of one of Hetzner’s locations going down, they do not represent any kind of partitioning inside the nodes subnet):

graph TB
  subgraph net["hcloud_network raya · 10.0.0.0/16"]
    subgraph zone["Hetzner eu-central"]
      subgraph hel1["hel1 · Helsinki"]
        cp["control-plane<br/>10.0.1.10"]
      end
      subnet(["subnet nodes · 10.0.1.0/24"])
    end
    gateway["Private gateway · 10.0.0.1"]
  end

  cp --> subnet
  subnet -.->|routes 10.0.0.0/8 via| gateway

  classDef failureDomain stroke-dasharray: 5 5
  class hel1 failureDomain