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KUKSA Bridge - Resource Isolation Guest

KUKSA databroker client running on the NUC Guest. Polls a button signal from the master's databroker and toggles a CPU workload (stress-ng) on the guest host via shell scripts.

Overview​

This bridge polls Vehicle.Cabin.ResourceIsolation.ButtonPressed from the master's KUKSA databroker. When a button press is detected, it toggles the stress-ng workload to simulate CPU load.

┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│  Master Node    │────▶│  KUKSA Broker   │────▶│  KUKSA Bridge   │
│  (Button Press) │     │  (Port 55556)   │     │  (this)         │
└─────────────────┘     └─────────────────┘     └────────┬────────┘
                                                         │
                                                         ▼
                                                ┌─────────────────┐
                                                │   stress-ng     │
                                                │   (CPU Load)    │
                                                └─────────────────┘

Configuration​

Settings are read from the .env file (baked into the image at build time).

.env File Format​

# Master node's KUKSA databroker address.
# Leave KUKSA_HOST empty: preflight/prepare_guest.sh fills it with the master IP
# before building the image.
KUKSA_HOST=
KUKSA_PORT=55556
KUKSA_PROTOCOL=grpc

# Shell scripts for toggle mode
TRIGGER_ON_SCRIPT=/app/script/trigger-on.sh
TRIGGER_OFF_SCRIPT=/app/script/trigger-off.sh

Deployment​

In the multi-node demo you do not run this container by hand:

Build manually (optional)​

cd multi_node/nuc_guest/kuksa-bridge
sudo podman build -t localhost/resiso-kuksa-bridge-guest:latest .

The Dockerfile COPYs bridge.py, .env and script/ into the image, so no volume mounts are required to run it.

Logs​

sudo podman logs resiso-kuksa-bridge-guest -f      # follow
sudo podman logs resiso-kuksa-bridge-guest --tail=20

Behavior​

  1. KUKSA Databroker Connection

    • Address: KUKSA_HOST:55556 (master's resource-isolation databroker), gRPC
    • Signal (polled): Vehicle.Cabin.ResourceIsolation.ButtonPressed

  2. Button Event Handling (toggle)

    • Button press (toggle ON) → execute trigger-on.sh
    • Next press (toggle OFF) → execute trigger-off.sh

  3. Workload Control

    • ON: setsid stress-ng --cpu 0 --cpu-method all --timeout 0 (runs on the host)
    • OFF: terminates the stress-ng process group / all stress-ng processes

Shell Scripts​

trigger-on.sh​

  • Kills any existing stress-ng processes
  • Starts stress-ng in background using nohup+disown
  • Uses all CPU cores with various stress methods

trigger-off.sh​

  • Terminates all stress-ng processes
  • Verifies clean termination

Notes​

  • The bridge runs in toggle mode: each button press alternates ON/OFF.
  • stress-ng runs on the host, detached from the bridge process (setsid).
  • .env values are baked in at build time; rebuild the image to change them.
  • For the full multi-node demo procedure, see ../../test_script/README.md.