TELEICU/Topology

referenceteleicuCARE 3.0+

The target topology for the TELEICU infrastructure across all 200+ sites.

Components

Control plane (cloud VMs)

1–3 virtual machines in reliable cloud environments, serving as the K3s control plane. These nodes:

- Run embedded etcd for HA control plane state - Host the K3s server process - Are reachable over Tailscale from all spoke/hub nodes - Run in cloud regions with stable power and internet - Are the management entry point for both Ansible and NixOS paths

Agent nodes (hospital sites)

Every hospital PC — whether spoke or hub — runs as a K3s agent node. Each agent:

- Runs K3s agent process, registered to the control plane - Hosts containerized TELEICU middleware workloads - Connects over Tailscale for all control-plane communication - Pulls its node-level configuration (Ansible pull or comin) - Reports monitoring data to VictoriaMetrics

Network topology

{{#mermaid:flowchart TB
    subgraph CP["Cloud Control Plane"]
        CP1["CP VM 1<br/>(etcd)"]
        CP2["CP VM 2<br/>(etcd)"]
        CP3["CP VM 3<br/>(etcd)"]
    end

    TS["Tailscale Mesh"]

    CP1 --- TS
    CP2 --- TS
    CP3 --- TS

    subgraph Agents["K3s Agent Nodes (200+)"]
        H["Hub Node<br/>K3s agent<br/>+ middleware"]
        S1["Spoke Node<br/>K3s agent<br/>+ middleware"]
        S2["Spoke Node<br/>K3s agent<br/>+ middleware"]
        SN["... (200 more)"]
    end

    TS --- H
    TS --- S1
    TS --- S2
    TS --- SN
}}

Node communication

All traffic between agent nodes and the control plane traverses Tailscale:

- K3s registration: agent → CP over Tailscale IPs - Configuration pull: ansible-pull or comin fetches from git repo (routed through CP or directly) - Metrics: node → VictoriaMetrics endpoint - Incident notifications: heartbeat missing → on-device agent classifies cause → alert routed to hub admin

No sensitive data in this page

IP addresses, subnets, DNS names, and specific cloud providers are not documented here. These are environment-specific and maintained in the deployment repository's encrypted variables.