Azure IoT Hub Direct Method verification

• Azure IoT Hub Direct Method verification
  • Pre-requisites
  • Running the sample
    • Infrastructure provisioners
      • Terraform
      • Azure command line interface
      • ARM template
    • Dotnet projects
  • Current status

The repository contains scripts and dotnet libraries to verify direct-method communication channel for Azure IoT Hub

The repository structure:

• arm_templates - bash scripts and ARM template to create and delete Resource Group, Azure IoT Hub and Azure Storage Account.
• cli - bash scripts to create and delete Resource Group with Azure IoT Hub and a Storage Account.
• clients - c# clients to simulate cloud and device services:
  • tf.az.iot.clients.device - simulates device, which listens to direct methods invocation and sends responses;
  • tf.az.iot.clients.service.listener - simulate service that listents any device response;
  • tf.az.iot.clients.service.sender - simulate service that invokes direct methods.
• terraform - terraform template to provision and destroy Resource Group with Azure IoT Hub and a Storage Account.

Pre-requisites

Azure IoT Hub client projects are implemented with VS 2017 and uses dotnet core 2.2. To run the samples you need dotnet core SDK to be installed.

arm_templates and cli requires Azure CLI to be installed and az login command to be invoked before running scripts.

terraform template was built using terraform version 0.11.11

Running the sample

Infrastructure provisioners

The repository has three provisioners that creates the same environment using different tools:

• Terraform template in tf folder
• Bash scripts with az cli commands in cli folder
• Bash scripts to create IoT Hub and Storage Account with ARM template in arm_template folder

Every provisioner as the last step generates env.vars file in the repository root folder. The file is required by dotnet projects.

Terraform

Navigate to tf folder with cd ./tf

To run terraform template

1. set corresponding values to terraform.tfvars file
2. terraform init
3. terraform plan -out=tfplan
4. terraform apply tfplan

To clean-up afterward:

1. terraform destroy -auto-approve
2. rm ./tfplan

Azure command line interface

Navigate to cli folder with cd ./cli

To run cli provisioner: ./az_create.sh $BASE_NAME $Location. Where $BASE_NAME is used as prefix for Resource Group ($BASE_NAME-rg).

To clean-up: ./az_delete.sh $BASE_NAME. Where $BASE_NAME should be the same as used in create script

ARM template

Navigate to arm_template folder with cd ./arm_template

To run cli provisioner: ./az_create.sh $BASE_NAME $Location. Where $BASE_NAME is used as prefix for Resource Group ($BASE_NAME-rg).

To clean-up: ./az_delete.sh $BASE_NAME. Where $BASE_NAME should be the same as used in create script

Dotnet projects

Every dotnet project requires env.vars file with credentials to access Azure IoT Hub and/or Azure Storage Account. The file is autogenerated by bash scripts or terraform template.

To verify Direct Method communication channel start all three projects.

Sample output:

• right top corner is Direct Method invoker. You can see it sent 2 events
• left top corner is Device Simulator, which listens for Direct Methods invocation and responds to them. You can see it sent 2 events in response to the requests from the previous clause.
• at the bottom is device response listener, which is connected to built-in device-2-cloud events endpoint.

Current status

At the moment, Azure IoT Hub provisioned with Terraform template does not provide device-2-cloud events:

UPDATE 10.03.2019 The same functionality works fine for IoT Hub created by ARM templates or with az cli commands

The same corrupted result might be achieved adding empty arrays to routing property in ARM template.