How to use .NET Core 3.x with Azure Function App Powershell Runtime? - azure

Question

I have created a new Function App using the below resource in my template:
{
"apiVersion": "2015-08-01",
"type": "Microsoft.Web/sites",
"name": "[parameters('caAppName')]",
"location": "[parameters('location')]",
"kind": "functionapp",
"dependsOn": [
"[resourceId('Microsoft.Web/serverfarms', parameters('hostingPlanName'))]",
"[resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountName'))]"
],
"identity": {
"type": "SystemAssigned"
},
"properties": {
"serverFarmId": "[resourceId('Microsoft.Web/serverfarms', parameters('hostingPlanName'))]",
"siteConfig": {
"appSettings": [
{
"name": "AzureWebJobsStorage",
"value": "[concat('DefaultEndpointsProtocol=https;AccountName=', variables('storageAccountName'), ';AccountKey=', listKeys(variables('storageAccountid'),'2015-05-01-preview').key1)]"
},
{
"name": "WEBSITE_CONTENTAZUREFILECONNECTIONSTRING",
"value": "[concat('DefaultEndpointsProtocol=https;AccountName=', variables('storageAccountName'), ';AccountKey=', listKeys(variables('storageAccountid'),'2015-05-01-preview').key1)]"
},
{
"name": "WEBSITE_CONTENTSHARE",
"value": "[toLower(parameters('caAppName'))]"
},
{
"name": "FUNCTIONS_EXTENSION_VERSION",
"value": "~3"
},
{
"name": "WEBSITE_NODE_DEFAULT_VERSION",
"value": "~10"
},
{
"name": "APPINSIGHTS_INSTRUMENTATIONKEY",
"value": "[reference(resourceId('microsoft.insights/components/', variables('applicationInsightsName')), '2015-05-01').InstrumentationKey]"
},
{
"name": "FUNCTIONS_WORKER_RUNTIME",
"value": "powershell"
},
]
}
}
I run the below code in the function app in the portal Write-Host "$([System.Security.Cryptography.X509Certificates.X509Certificate2].Assembly.Location)"
I get D:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.2.8\System.Security.Cryptography.X509Certificates.dll
But if I use the Function App console:
D:\Program Files\dotnet\shared\Microsoft.NETCore.App> ls
2.2.8
2.2.8.installed
3.0.3
3.0.3.installed
3.1.3
3.1.3.installed
So 3.1.3 is present, but the function is not executing with it.
I only even noticed because I tried to use System.Security.Cryptography.PbeParameters and the type is missing (along with some other AsymmetricAlgorithm stuff)
How do I resolve this?

Answer 1

The .NET Core version is determined by the Azure PowerShell worker, which depends on the PowerShell SDK. PowerShell 6 is the only version currently available in Azure Functions, and it depends on .NET Core 2.x, this is why your PowerShell Function is executed in this context. In order to use .NET Core 3.x, you have the following options:
recommended: wait for PowerShell 7 support in Azure Functions (expected to be deployed within the next 2-4 weeks);
spawn a separate executable from your PowerShell function.