Hi !

The post title is very descriptive, however let me share some more context on why I needed this scenario.

I’m currently working in an Azure IoT custom module. I got installed the Azure IoT extensions on Visual Studio Code, so everything works great on the Hello World mode. Once I wrote my code logic in C#, I can easily build my IoT Edge Solution.

My default configuration focus to an amd64 platform. I got this defined in my settings.json

{
    "azure-iot-edge.defaultPlatform": {
        "platform": "amd64",
        "alias": null
    }
}

This is a sample log output, using my local docker in Windows 10. Everything works fine.

[+] Building 0.7s (16/16) FINISHED
 => [internal] load build definition from Dockerfile.amd64                                                                                                                                                                                  0.1s
 => => transferring dockerfile: 38B                                                                                                                                                                                                         0.1s 
 => [internal] load .dockerignore                                                                                                                                                                                                           0.1s 
 => => transferring context: 34B                                                                                                                                                                                                            0.1s 
 => [internal] load metadata for mcr.microsoft.com/dotnet/core/runtime:3.1-buster-slim                                                                                                                                                      0.5s
 => [internal] load metadata for mcr.microsoft.com/dotnet/core/sdk:3.1-buster                                                                                                                                                               0.5s 
 => [build-env 1/6] FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster@sha256:0fece15a102530aa2dad9d247bc0d05db6790917696377fc56a8465604ef1aff                                                                                               0.0s
 => [internal] load build context                                                                                                                                                                                                           0.0s 
 => => transferring context: 446B                                                                                                                                                                                                           0.0s 
 => [stage-1 1/4] FROM mcr.microsoft.com/dotnet/core/runtime:3.1-buster-slim@sha256:e84300e54209cad66611b0b483cfe8c007d3bb5450388ff58e7f15d025917817                                                                                        0.0s 
 => CACHED [stage-1 2/4] WORKDIR /app                                                                                                                                                                                                       0.0s
 => CACHED [build-env 2/6] WORKDIR /app                                                                                                                                                                                                     0.0s 
 => CACHED [build-env 3/6] COPY *.csproj ./                                                                                                                                                                                                 0.0s 
 => CACHED [build-env 4/6] RUN dotnet restore                                                                                                                                                                                               0.0s 
 => CACHED [build-env 5/6] COPY . ./                                                                                                                                                                                                        0.0s 
 => CACHED [build-env 6/6] RUN dotnet publish -c Release -o out                                                                                                                                                                             0.0s 
 => CACHED [stage-1 3/4] COPY --from=build-env /app/out ./                                                                                                                                                                                  0.0s 
 => CACHED [stage-1 4/4] RUN useradd -ms /bin/bash moduleuser                                                                                                                                                                               0.0s 
 => exporting to image                                                                                                                                                                                                                      0.0s 
 => => exporting layers                                                                                                                                                                                                                     0.0s 
 => => writing image sha256:8d38fb01640fb566e761231c1a646df35bb83f24dfbb0fdea92bc4db62576e12                                                                                                                                                0.0s 
 => => naming to <...>

If I want to change the target platform to build an arm32 image, I change my settings.json file to:

{
    "azure-iot-edge.defaultPlatform": {
        "platform": "arm32v7",
        "alias": null
    }
}

However I got this ugly error, trying to build this

=> CACHED [build-env 2/6] WORKDIR /app                                                                                                                                                                                                     0.0s 
 => CACHED [build-env 3/6] COPY *.csproj ./                                                                                                                                                                                                 0.0s 
 => ERROR [build-env 4/6] RUN dotnet restore                                                                                                                                                                                                0.5s
------
 > [build-env 4/6] RUN dotnet restore:
#10 0.450 A fatal error occurred, the folder [/usr/share/dotnet/host/fxr] does not contain any version-numbered child folders
------
executor failed running [/bin/sh -c dotnet restore]: exit code: 131

There seems to be an error here, outside of my docker knowledge.

Of course, a test path could involve the use of a remote ARM32 Docker Environment to build my Azure IoT Edge C# Module. I followed my previous posts steps to enable SSH password-less access to my Raspberry Pi and also manage docker as non-root users (see references).

Now I can define a specific DOCKER EXECUTOR to build my images. I changed my settings.json file to define this executor. Note that you must define a standard SSH connection, this may involve your device name or IP Address.

{
    "azure-iot-edge.defaultPlatform": {
        "platform": "arm32v7",
        "alias": null
    },
    "azure-iot-edge.executor.env": {
         "DOCKER_HOST": "ssh://pi@<Raspberry PI Address>"
    }
}

Important: once you changed your settings.json configuration, you need to reload your VSCode environment. You can close and open the IDE, or even better, invoke the [Reload Window] command.

Now we can sucesfully build the Azure IoT module. the output log will be similar to this one:

Sending build context to Docker daemon  24.06kB
Step 1/12 : FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster-arm32v7 AS build-env
 ---> 3cdfdcca7cd6
Step 2/12 : WORKDIR /app
 ---> Using cache
 ---> 8c3252bfdefb
Step 3/12 : COPY *.csproj ./
 ---> Using cache
 ---> e6fe11cb659e
Step 4/12 : RUN dotnet restore
 ---> Using cache
 ---> 12453c83de65
Step 5/12 : COPY . ./
 ---> Using cache
 ---> 107c1dfccfa3
Step 6/12 : RUN dotnet publish -c Release -o out
 ---> Using cache
 ---> 603a93c80b0e
Step 7/12 : FROM mcr.microsoft.com/dotnet/core/runtime:3.1-buster-slim-arm32v7
 ---> 2bb8fc093aad
Step 8/12 : WORKDIR /app
 ---> Using cache
 ---> c8a93a2a7b90
Step 9/12 : COPY --from=build-env /app/out ./
 ---> Using cache
 ---> f72a492270ad
Step 10/12 : RUN useradd -ms /bin/bash moduleuser
 ---> Using cache
 ---> 082a4568867b
Step 11/12 : USER moduleuser
 ---> Using cache
 ---> 2c5e7b562289
Step 12/12 : ENTRYPOINT ["dotnet", "UDPFwder.dll"]
 ---> Using cache
 ---> f523123332f9
Successfully built f523123332f9
Successfully tagged <...>
SECURITY WARNING: You are building a Docker image from Windows against a non-Windows Docker host. All files and directories added to build context will have '-rwxr-xr-x' permissions. It is recommended to double check and reset permissions for sensitive files and directories.

And that’s it! Using a Raspberry Pi device to build Net Azure IoT modules seems to be the fix to build ARM32 platforms.

References

• Azure IoT Edge for Visual Studio Code

My posts on Raspberry Pi ⚡🐲⚡

Dev posts for Raspberry Pi

• How to grant permissions to a folder after git clone, to perform dotnet restore on a Raspberry Pi
• How to install .Net Core 3.1 in a Raspberry Pi 4
• Installing Visual Studio Code in a Raspberry Pi 4, run as root, fix black screen
• How to install .Net Core in a Raspberry Pi 4 and test with Hello World
• Build and Run C# NetCore projects in a Raspberry Pi 4 with Visual Studio Code
• Let’s do some Git dev in Raspberry Pi 4 (GitHub and Azure DevOps!)
• Install OpenCV
• Install Python 🐍 Virtual Environments in Raspberry Pi
• Setup SSH passwordless access to remote work with Docker 🐳
• Manage Docker 🐳 as a non-root user
• Build Docker 🐳 images from Visual Studio Code remotely using a Raspberry Pi

Tools and Apps for Raspberry Pi

• Where is my Task Manager in RaspberryPi? Let’s try htop
• Multi-monitor 📺 in Raspberry Pi 4 rocks !
• Double Commander on RaspberryPi4, because files are important
• How to install Docker 🐳 in a Raspberry Pi 4
• Installing Visual Studio Code in a Raspberry Pi
• Installing Visual Studio Code in a Raspberry Pi, run as root, fix black screen (Updated)
• 6 commands to install OpenCV for Python 🐍 in a Raspberry Pi 4

Setup the device

• 1st Setup without monitor 📺: auto connect to WiFi 📶, enable SSH, update and more
• Setup without monitor: enable VNC
• How to enable auto start with HDMI safe mode
• Running a Python 🐍 script in a Python Virtual Environment on reboot / startup
• Setup Wifi on Ubuntu

Hardware

• Ice Tower, the best cooler 🧊 for your device! From 70C to <40C in a 60 minutes process running at 100% in all 4 cores
• Intel Neural Stick 2, Performance differences in Face Recognition using OpenVino

Azure IoT

• Install ☁ Azure IoT on Raspberry Pi
• Deploy ☁ Azure Blob Storage on IoT Edge, lessons learned
• Connect to ☁ Azure Blob Storage on IoT Edge using Microsoft Azure Storage Explorer
• Lesson learned and tips on how to install Azure IoT Edge on Ubuntu on a Raspberry Pi
• Azure IoT Explorer, in preview and awesome
• Mapping a local ☁ Azure IoT Edge folder module with an Edge device folder 📁
• Creating a folder 📂 in the docker definition in an ☁ Azure IoT Edge

¿Con ganas de ponerte al día?

En Lemoncode te ofrecemos formación online impartida por profesionales que se baten el cobre en consultoría:

• Si tienes ganas de ponerte al día con Front End (ES6, Typescript, React, Angular, Vuejs…) te recomendamos nuestros Máster Front End: https://lemoncode.net/master-frontend#inicio-banner
• Si te quieres poner al día en Backend (stacks .net y nodejs), te aconsejamos nuestro Bootcamp Backend: https://lemoncode.net/bootcamp-backend#bootcamp-backend/banner
• Y si tienes ganas de meterte con Docker, Kubernetes, CI/CD…, tenemos nuestro Bootcamp Devops: https://lemoncode.net/bootcamp-devops#bootcamp-devops/inicio