SBCX-TN-003: Deploying modules to Azure IoT Edge-enabled SBCX with Visual Studio Code
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This technical note was validated against specific versions of hardware and software. It may not work with other versions. |
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Contents
History[edit | edit source]
| Version | Date | Notes |
|---|---|---|
| 1.0.0 | August 2019 | First public release |
Introduction[edit | edit source]
The goal of this document is to show how to deploy modules to an Azure IoT Edge-enabled SBC Axel board. It is recalled that, according to Microsoft documentation, modules are
the smallest computation units managed by IoT Edge, and can contain Microsoft services (such as Azure Stream Analytics), 3rd-party services or your own solution-specific code.
There are different methods to deploy such modules to the IoT Edge-enabled devices. This Technical Note (TN for short) will describe how to use Visual Studio Code (VSC) to carry out such an operation on the SBCX single-board computer.
This article is based on this previous TN: SBCX-TN-002: Running Microsoft Azure IoT Edge runtime. As such, SBCX-TN-002 is a prerequisite to complete this TN.
The procedure illustrated here is based on this document, whose reading is highly recommended.
For more detailed information about Azure IoT Edge modules, please see this page.
Setting up VSC[edit | edit source]
To set up Visual Studio Code, the Azure IoT Tools extension package has to be installed.
After installing this package, the Welcome to Azure IoT Tools tab should open automatically:
This tab is extremely convenient to establish the connection between VSC and the IoT hub the we created previously on the Azure platform.
After installing the Azure IoT Tools extension package, VSC suggests to install the iotedgehubdev as well. Although it is not necessary, this package may be useful for debugging tasks. For more details, please refer to this page.
Deploying a simple module[edit | edit source]
Following the example illustrated here, the first step is to create a deployment.json file. In this case, the Simulated Temperature Sensor module will be deployed to the edge device.
The following picture shows the deployment.json file and the Azure IoT Hub Devices section in the bottom left corner of VSC window. This section in turn lists the connected edge devices—sbcx in the example—and their running modules—edgeAgent and edgeHub in the example.
By right-clicking on the sbcx device, the Create Deployment for Single Device item can be selected. This action starts the deployment process. At the end of this process, the Deployment succeeded message should appear on the output console:
Verifying the transmission of data from the edge device to the cloud[edit | edit source]
After refreshing the lists of the modules associated with the sbcx device, a new module named SimulatedTemperatureSensor should appear:
The SimulatedTemperatureSensor module should appear in the list of the modules on the cloud side as well ...
... and its status should be Connected:
There are different ways to verify that the Simulated Temperature Sensor module is sending data to the cloud. In VSC, it is possible to monitor the data stream by clicking the Start Monitoring Built-in Event Endpoint item in the drop-down menu associated with the sbcx device:
In the output console, the messages relating to the transmission of such data will be visible:
[IoTHubMonitor] [5:16:56 PM] Message received from [sbcx/SimulatedTemperatureSensor]:
{
"body": {
"machine": {
"temperature": 100.66939129711574,
"pressure": 10.076259768025844
},
"ambient": {
"temperature": 20.67014677551116,
"humidity": 24
},
"timeCreated": "2019-08-19T15:16:56.5401594Z"
},
"applicationProperties": {
"sequenceNumber": "184",
"batchId": "39f619d0-72ff-4c1f-9474-294158b70db2"
}
}
The transmission of data can be verified on the edge device too by issuing the following command:
armbian@sbcx:~$ sudo iotedge logs SimulatedTemperatureSensor -f
[2019-08-19 15:00:52 +00:00]: Starting Module
SimulatedTemperatureSensor Main() started.
Initializing simulated temperature sensor to send 500 messages, at an interval of 5 seconds.
To change this, set the environment variable MessageCount to the number of messages that should be sent (set it to -1 to send unlimited messages).
Information: Trying to initialize module client using transport type [Amqp_Tcp_Only].
Information: Successfully initialized module client of transport type [Amqp_Tcp_Only].
08/19/2019 15:01:32> Sending message: 1, Body: [{"machine":{"temperature":20.830871543186191,"pressure":0.9807322011224775},"a
mbient":{"temperature":20.538326477649775,"humidity":26},"timeCreated":"2019-08-19T15:01:31.9148845Z"}]
08/19/2019 15:01:38> Sending message: 2, Body: [{"machine":{"temperature":21.013124713447468,"pressure":1.0014952205193317},"a
mbient":{"temperature":21.149835604079922,"humidity":26},"timeCreated":"2019-08-19T15:01:38.1592817Z"}]
08/19/2019 15:01:43> Sending message: 3, Body: [{"machine":{"temperature":22.038820587465921,"pressure":1.1183466492049783},"a
mbient":{"temperature":21.027865147929575,"humidity":25},"timeCreated":"2019-08-19T15:01:43.206327Z"}]
What's under the hood[edit | edit source]
For readers interested in the technologies underlying the Azure IoT Edge solution, it is worth remembering that modules are implemented as Docker containers. After deploying the Simulated Temperature Sensor module, for instance, it is easy to verify that a new container image is installed on the edge device:
armbian@sbcx:~$ sudo docker image ls REPOSITORY TAG IMAGE ID CREATED SIZE mcr.microsoft.com/azureiotedge-simulated-temperature-sensor 1.0 a626b1a36236 4 weeks ago 200MB mcr.microsoft.com/azureiotedge-hub 1.0 3a84bfb86c7d 4 weeks ago 252MB mcr.microsoft.com/azureiotedge-agent 1.0 58276103181c 4 weeks ago 238MB mcr.microsoft.com/azureiotedge-diagnostics 1.0.8 a480fa622e2a 4 weeks ago 7.34MB
Similarly, one can use docker command line to verify that the Simulated Temperature Sensor module is listed among running containers:
armbian@sbcx:~$ sudo docker container ls CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 145db7780bec mcr.microsoft.com/azureiotedge-simulated-temperature-sensor:1.0 "/bin/sh -c 'echo \"$…" 18 hours ago Up 17 hours SimulatedTemperatureSensor 200e8563544f mcr.microsoft.com/azureiotedge-hub:1.0 "/bin/sh -c 'echo \"$…" 18 hours ago Up 17 hours 443/tcp, 5671/tcp, 8883/tcp edgeHub da40f11b4c33 mcr.microsoft.com/azureiotedge-agent:1.0 "/bin/sh -c 'echo \"$…" 10 days ago Up 17 hours edgeAgent
The same information can be retrieved by using iotedge command line:
armbian@sbcx:~$ sudo iotedge list NAME STATUS DESCRIPTION CONFIG edgeHub running Up 17 hours mcr.microsoft.com/azureiotedge-hub:1.0 SimulatedTemperatureSensor running Up 17 hours mcr.microsoft.com/azureiotedge-simulated-temperature-sensor:1.0 edgeAgent running Up 17 hours mcr.microsoft.com/azureiotedge-agent:1.0
It is also interesting to list the processes running inside the azureiotedge-simulated-temperature-sensor container:
root@sbcx:~# docker container top 145db7780bec UID PID PPID C STIME TTY TIME CMD armbian 2612 2586 0 10:24 ? 00:00:20 /usr/bin/dotnet SimulatedTemperatureSensor.dll
The /usr/bin/dotnet file is an ARM executable ...
root@sbcx:/var/lib/docker/overlay2/b4cc9541e8175bae26aa42952490a0b2fcdd5895bfe18f8092b58c27531259b6/merged/usr/share/dotnet# file dotnet dotnet: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 2.6.32, BuildID[sha1]=ef6dc8332270899ce1c7de629bdbcc95168fc710, stripped
... while SimulatedTemperatureSensor.dll is a Portable Executable file:
root@sbcx:/var/lib/docker/overlay2/b4cc9541e8175bae26aa42952490a0b2fcdd5895bfe18f8092b58c27531259b6# file merged/app/SimulatedTemperatureSensor.dll merged/app/SimulatedTemperatureSensor.dll: PE32 executable (console) Intel 80386 Mono/.Net assembly, for MS Windows
Unfortunately, at the time of this writing, the official source code of the Simulated Temperature Sensor module was not available. The original repository was cloned here, however.
