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Greengrass V2 samples using AWS IoT Device SDK v2 for Python

You can find the full API documentation for the Greengrass V2 IPC interface using the Python SDK here: https://aws.github.io/aws-iot-device-sdk-python-v2/awsiot/greengrasscoreipc.html

Sample: Low-Level IPC

Folder: low_level_ipc/

Once installed and running, this sample publishes messages to AWS IoT Core. It uses the low-level Greengrass v2 Inter-Process-Communication API.

See the other samples for higher-level APIs to reduce the amount of code you have to write and maintain.

Sample: Publish/Subscribe to the cloud with AWS IoT Core

Folder: pubsub_cloud

Once installed and running, this sample subscribes to the hello/world topic. You can use the MQTT Test Client to publish a message to this topic, while also subscribing to hello/world/response in the MQTT Test Client. The Greengrass device will receive the message and reply back on the response topic.

Sample: Public/Subscribe on the local device between Greengrass components

Folder: pubsub_local

Once installed and running, this sample subscribes to the hello/world topic. You can use a second component to publish a message and receive a reply message on the hello/world/response topic. These messages are not sent to AWS IoT Core (the cloud). This pub/sub mechanism is only connecting different components running on the same Greengrass device. You can use the Greegrass CLI to publish or subscribe to these local topics:

  • greengrass-cli pubsub sub --topic hello/world/response
  • greengrass-cli pubsub pub --topic hello/world --message Hi!

Sample: Shadow Management

Folder: shadows

Once installed and running, this sample will retrieve a named shadow special_shadow when the component first starts executing, and then periodically update the shadow document with a new reported state every few seconds.

This component depends on the AWS-provided ShadowManager component. You need to configure it to synchronize named shadows from the local device to the cloud:

strategy:
    type: realTime
synchronize:
    coreThing:
    namedShadows:
        - special_shadow
    direction: betweenDeviceAndCloud

Sample: Deployment Configuration

Folder: deployment_configuration

Once installed and running, this sample will retrieve the component's deployment configuration and start a web server based on the provided parameters. Re-deploying with different parameters will update the component and upon restart of the Python process, it will start the web server based on these new parameters.

Deployment Helpers

Deploy component locally using Greengrass CLI:

func gg_deploy() {
    COMPONENT_NAME=$(sed -nr 's/ComponentName: ([a-zA-Z.-_]+)/\1/p' recipe.yaml)
    COMPONENT_VERSION=$(sed -nr 's/ComponentVersion: (.+)/\1/p' recipe.yaml | tr -d '"' | tr -d "'")
    
    mkdir -p build/artifacts/$COMPONENT_NAME/$COMPONENT_VERSION/
    command cp code.py build/artifacts/$COMPONENT_NAME/$COMPONENT_VERSION/
    
    mkdir -p build/recipes/
    command cp recipe.yaml build/recipes/$COMPONENT_NAME.yaml

    RECIPES=$PWD/build/recipes
    ARTIFACTS=$PWD/build/artifacts
    sudo /greengrass/v2/bin/greengrass-cli deployment create \
        --recipeDir=$RECIPES \
        --artifactDir=$ARTIFACTS \
        --merge=$COMPONENT_NAME=$COMPONENT_VERSION
}

func gg_remove() {
    COMPONENT_NAME=$(sed -nr 's/ComponentName: ([a-zA-Z.-_]+)/\1/p' recipe.yaml)
    sudo /greengrass/v2/bin/greengrass-cli deployment create \
        --recipeDir=$RECIPES \
        --artifactDir=$ARTIFACTS \
        --remove=$COMPONENT_NAME
}