Covers how to set up a greengrass POC from Cloudformation

Summary

At the end of this POC you will have a AWS Greengrass stack containing:

• 1 x Core
• 1 x Group
• 2 x Devices

You will have verified that you can send messages from one devices to another

Assumptions

This assumes:

• You have a Greengrass core up and running

If you need to set one up you can use my AMI and run on EC2. Check it out here https://github.com/paulhopkins11/aws-greengrass-core-ami

Steps

1. Generate some certificates

export DEVICE1_CERTIFICATE_ARN=$(aws iot create-keys-and-certificate \
    --profile <YOUR_AWS_PROFILE> \
    --region <YOUR_AWS_REGION> \
    --set-as-active \
    --certificate-pem-outfile certs/device1.cert.pem \
    --public-key-outfile certs/device1.public.key \
    --private-key-outfile certs/device1.private.key | jq '.certificateArn' -r)
echo $DEVICE1_CERTIFICATE_ARN
export DEVICE2_CERTIFICATE_ARN=$(aws iot create-keys-and-certificate \
    --profile <YOUR_AWS_PROFILE> \
    --region <YOUR_AWS_REGION> \
    --set-as-active \
    --certificate-pem-outfile certs/device2.cert.pem \
    --public-key-outfile certs/device2.public.key \
    --private-key-outfile certs/device2.private.key | jq '.certificateArn' -r)
echo $DEVICE2_CERTIFICATE_ARN

2. Create the Greengrass Stack

TODO - CORE CONNECTIVITY SETTINGS (see NB below)

TODO - Core -> Settings -> Automatically detect and override connection information

TODO - Core -> Settings -> Local logs configuration

Create the stack using:

aws cloudformation create-stack \
--stack-name greengrass-stack \
--template-body file://./greengrass_stack_cf.yaml \
--profile <YOUR_AWS_PROFILE> \
--region <YOUR_AWS_REGION> \
--capabilities CAPABILITY_NAMED_IAM \
--parameters \
ParameterKey=CoreCertificateArn,ParameterValue=<YOUR_CORE_CERTIFICATE_ARN> \
ParameterKey=Device1CertificateArn,ParameterValue=$DEVICE1_CERTIFICATE_ARN \
ParameterKey=Device2CertificateArn,ParameterValue=$DEVICE2_CERTIFICATE_ARN

Update the stack using:

aws cloudformation update-stack \
--stack-name greengrass-stack \
--template-body file://./greengrass_stack_cf.yaml \
--profile <YOUR_AWS_PROFILE> \
--region <YOUR_AWS_REGION> \
--capabilities CAPABILITY_NAMED_IAM \
--parameters \
ParameterKey=CoreCertificateArn,ParameterValue=<YOUR_CORE_CERTIFICATE_ARN> \
ParameterKey=Device1CertificateArn,ParameterValue=$DEVICE1_CERTIFICATE_ARN \
ParameterKey=Device2CertificateArn,ParameterValue=$DEVICE2_CERTIFICATE_ARN

3. Deploy the Group

Navigate to the Group in the AWS Console and choose Deploy

NB. If running the Pub and Sub locally and the core on EC2 you need to manually add the public IP of your EC2 instance into the Connectivity settings:

• Navigate to TestCore1 in the AWS Console
• Choose Connectivity
• Edit the endpoints
• Add the public IP and port 8883

4. Setup the python environment

python3 -m venv ~/virtualenv/greengrass
source ~/virtualenv/greengrass/bin/activate 
python3 -m pip install awsiotsdk

5. Download the sample code

wget https://raw.githubusercontent.com/aws/aws-iot-device-sdk-python-v2/main/samples/basic_discovery.py -P src/

6. Run the Subscriber

make sub -e region=<YOUR_AWS_REGION>

You should see this successfully discover

7. Run the Publisher

make pub -e region=<YOUR_AWS_REGION>

You should now see the publisher send 10 messages. You should see these received by the subscriber