Loop component

The custom componentcomponent
Greengrass component — a versioned unit of software on the core (AWS public components or custom recipes such as GgEdgeLoop / ZoneAnomaly). com.example.GgEdgeLoop subscribes to pubsubpubsub
Greengrass interprocess pub/sub — in-process messaging between components on the core (the closed-loop component uses it for sensor/actuator topics). topic gg-edge/sensor and publishes JSON commands on gg-edge/actuator/<thing>. The MQTT bridgeMQTT bridge
aws.greengrass.clientdevices.mqtt.Bridge — maps topics between LocalMqtt (Moquette), Pubsub (components), and IotCore. maps those topics to MoquetteMoquette
aws.greengrass.clientdevices.mqtt.Moquette — local MQTT broker on the core. Not Mosquitto; client devices connect here over mTLS. ( ESP32-S3ESP32-S3
Espressif ESP32-S3 — Wi‑Fi microcontroller used here as the Greengrass client device (not a second core).) and IoT CoreIoT Core
AWS IoT Core — cloud MQTT and device identity service. Client devices use it for discovery; the MQTT bridge forwards zone topics here, where IoT rules route them to other AWS services..

Manual Nucleus install does not include greengrass-cligreengrass-cli
Greengrass CLI — local tool under /greengrass/v2/bin/greengrass-cli for listing components and creating local deployments on the core. — add Cli in a cloud deployment that keeps Auth / Moquette / Bridge / IPDetector (a new deployment to the Thing group replaces the previous root set).

This page deploys the loop locally to prove the LAN path first. After Prove the LAN loop, Deploy from the cloud replaces it with a cloud-registered version from S3.

Steps on this page:

1. 1Deploy greengrass-clicreate-deploymentcloud
2. 2Copy recipe + artifactcp → /opt/gg-edgeNUC
3. 3Local deploygreengrass-cli … --mergeNUC
4. 4Verify RUNNINGcomponent list · tail logNUC

Deploy Cli from the cloud (keeping the client-device stack), then build the closed-loop component locally with greengrass-cli. RUNNING + asubscribed to gg-edge/sensor log line = good.

1. Deploy greengrass-cli (cloud)

Render deployment JSON (client stack + Cli)

CORE_THING_GROUP_ARN=$(aws iot describe-thing-group \
  --thing-group-name "$CORE_THING_GROUP" \
  --query thingGroupArn --output text)
CLI_VER=$(aws greengrassv2 list-components --scope PUBLIC \
  --query "components[?componentName=='aws.greengrass.Cli'].latestVersion.componentVersion" \
  --output text)
echo "Cli=$CLI_VER"
sed -e "s|TARGET_THING_GROUP_ARN|${CORE_THING_GROUP_ARN}|g" \
    -e "s|CLIENT_THING_PREFIX|${CLIENT_THING_PREFIX}|g" \
    -e "s|CLI_COMPONENT_VERSION|${CLI_VER}|g" \
    artifacts/deployments/client-device-support-with-cli.json \
  > /tmp/gg-edge-with-cli.json
aws greengrassv2 create-deployment \
  --cli-input-json file:///tmp/gg-edge-with-cli.json

Cli=2.18.3
{
    "deploymentId": "2ab5a9fe-c150-4ec8-aa4e-2de4e4d67ecc"
}

Wait until list-effective-deployments shows SUCCEEDED, then on the NUC:

sudo /greengrass/v2/bin/greengrass-cli -V

Greengrass CLI Version: 2.18.3

2. Copy recipe and artifact on the NUC

Requires awsiotsdk on the NUC (installed in Install Nucleus). Without it, com.example.GgEdgeLoop goes BROKEN (ModuleNotFoundError: awsiot).

Preferred: keep a checkout of this repo on the NUC, then copy into /opt/gg-edge (SSH/scp from the workstation also works).

On the NUC (repo root of the checkout):

sudo mkdir -p /opt/gg-edge/recipes \
  /opt/gg-edge/artifacts/com.example.GgEdgeLoop/1.0.1
sudo cp artifacts/components/recipes/com.example.GgEdgeLoop-1.0.1.yaml \
  /opt/gg-edge/recipes/
sudo cp artifacts/components/artifacts/com.example.GgEdgeLoop/1.0.1/loop.py \
  /opt/gg-edge/artifacts/com.example.GgEdgeLoop/1.0.1/

(no output)

For local deploy, Nucleus reads artifacts from --artifactDir. The recipe’s s3:// URI is used later when you ship it from the cloud.

3. Local deploy with greengrass-cli

Still on the NUC:

sudo /greengrass/v2/bin/greengrass-cli deployment create \
  --recipeDir /opt/gg-edge/recipes \
  --artifactDir /opt/gg-edge/artifacts \
  --merge "com.example.GgEdgeLoop=1.0.1"

Local deployment submitted! Deployment Id: …

4. Verify

List components

sudo /greengrass/v2/bin/greengrass-cli component list

Component Name: com.example.GgEdgeLoop
    Version: 1.0.1
    State: RUNNING
…

Tail component log

sudo tail -f /greengrass/v2/logs/com.example.GgEdgeLoop.log

… subscribed to gg-edge/sensor

Expect a log line that the component subscribed to gg-edge/sensor.

Note

Do not deploy Cli alone to the Thing group — that removes Moquette and Auth. Always include the client-device components (see client-device-support-with-cli.json).

Next: Flash zones.