Azure Bicep: Deploy Azure Functions for PowerShell on Linux OS

This article aims to help you deploy Azure Functions for PowerShell on Linux OS in your environment using Infrastructure-as-Code with Azure Bicep.

Azure Bicep is a domain-specific language (DSL) that uses a declarative syntax to deploy Azure resources.

The Bicep is an abstraction on top of Azure Resource Manager (ARM) templates to define Azure resources using declarative Infrastructure as Code.

During Microsoft Ignite 2022, it was announced the Azure Functions support for PowerShell on Linux OS is generally available in Azure Functions runtime 4.0 on all hosting plans.

You can now develop Azure Functions PowerShell apps locally and deploy them to Azure Functions on Linux OS.

This article will show how you can deploy Azure Functions for PowerShell on Linux OS using Azure Bicep, a Domain Specific Language (DSL), for deploying Azure resources declaratively.

Prerequisites

• An Active Azure account: You can create an account for free.
• Azure Bicep is installed on your local machine.
• Azure PowerShell. See: Install Azure PowerShell.
• A resource group in your Azure subscription

Let's get started!

1. Solution Overview

We will author a Bicep template that creates an Azure Function for PowerShell on Linux OS.

The solution will include the following files:

• 📄 main.bicep: This is the Bicep template
• 📄 azuredeploy.parameters.json: This parameter file contains the values to use for deploying your Bicep template.

2. Azure Bicep Template — parameters

Create a new file in your working directory and name it main. Bicep. We will define the following parameters:

param functionAppName string
param location string
param hostingPlanName string
param alwaysOn bool
param use32BitWorkerProcess bool
param ftpsState string
param storageAccountName string
param linuxFxVersion string
param sku string
param skuCode string

@description('Storage Account type')
@allowed([
  'Standard_LRS'
  'Standard_GRS'
  'Standard_RAGRS'
])
param storageAccountType string = 'Standard_LRS'

3. Azure Bicep Template — variables

We will define the following variable:

var applicationInsightsName = functionAppName

4. Azure Bicep Template — resources

We will define the following resources:

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-02-01' = {
  name: storageAccountName
  location: location
  sku: {
    name: storageAccountType
  }
  kind: 'Storage'
}

resource hostingPlan 'Microsoft.Web/serverfarms@2021-02-01' = {
  name: hostingPlanName
  location: location
  kind: 'linux'
  properties: {
    reserved: true
    zoneRedundant: true
  }
  sku: {
    tier: sku
    name: skuCode
  }
}

resource applicationInsights 'microsoft.insights/components@2020-02-02' = {
  name: applicationInsightsName
  location: location
  tags: {
    'hidden-link:${resourceId('Microsoft.Web/sites', applicationInsightsName)}': 'Resource'
  }
  properties: {
    Application_Type: 'web'
  }
  kind: 'web'
}

resource functionApp 'Microsoft.Web/sites@2022-03-01' = {
  name: functionAppName
  kind: 'functionapp,linux'
  location: location
  properties: {
    siteConfig: {
      appSettings: [
        {
          name: 'FUNCTIONS_EXTENSION_VERSION'
          value: '~4'
        }
        {
          name: 'FUNCTIONS_WORKER_RUNTIME'
          value: 'powershell'
        }
        {
          name: 'APPINSIGHTS_INSTRUMENTATIONKEY'
          value: reference('microsoft.insights/components/azinsiderfun', '2015-05-01').InstrumentationKey
        }
        {
          name: 'APPLICATIONINSIGHTS_CONNECTION_STRING'
          value: reference('microsoft.insights/components/azinsiderfun', '2015-05-01').ConnectionString
        }
        {
          name: 'AzureWebJobsStorage'
          value: 'DefaultEndpointsProtocol=https;AccountName=${storageAccountName};AccountKey=${listKeys(storageAccount.id, '2019-06-01').keys[0].value};EndpointSuffix=core.windows.net'
        }
      ]
      cors: {
        allowedOrigins: [
          'https://portal.azure.com'
        ]
      }
      use32BitWorkerProcess: use32BitWorkerProcess
      ftpsState: ftpsState
      linuxFxVersion: linuxFxVersion
      alwaysOn: alwaysOn
    }
    serverFarmId: hostingPlan.id
    clientAffinityEnabled: false
    virtualNetworkSubnetId: null
    httpsOnly: true
  }
  dependsOn: [
    applicationInsights
  ]
}

5. Parameters file

Create a new file named azuredeploy.parameters.json. The code below shows the definition of the parameters file:

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "functionAppName": {
            "value": "azinsiderfun"
        },
        "location": {
            "value": "East US"
        },
        "hostingPlanName": {
            "value": "ASP-azinsiderdemo-ba3e"
        },
        "alwaysOn": {
            "value": true
        },
        "ftpsState": {
            "value": "FtpsOnly"
        },
        "storageAccountName": {
            "value": "azinsiderdemob924"
        },
        "sku": {
            "value": "PremiumV2"
        },
        "skuCode": {
            "value": "P1v2"
        },
        "use32BitWorkerProcess": {
            "value": false
        },
        "linuxFxVersion": {
            "value": "PowerShell|7.2"
        }
    }
}

6. Azure Bicep Template — Deployment

We will use the command below to deploy our Bicep template:

$date = Get-Date -Format "MM-dd-yyyy"
$rand = Get-Random -Maximum 1000
$deploymentName = "AzInsiderDeployment-"+"$date"+"-"+"$rand"

New-AzResourceGroupDeployment -Name $deploymentName -ResourceGroupName azinsider_demo -TemplateFile .\main.bicep -TemplateParameterFile .\azuredeploy.parameters.json -c

The image below shows the preview of the deployment:

Then we will execute the deployment. The image below shows the deployment output:

You can find the code of this solution in the following URL; feel free to contribute!
https://github.com/daveRendon/azinsider/tree/main/application-workloads/azure-functions-for-powershell-linux

You can go to the Azure Portal and review the configuration of the Azure Function resource type as shown below:

Note that the configuration reflects the use of PowerShell Core 7.2. We can also validate the OS in the overview tab, as shown below:

Conclusion

This article reviewed how to leverage Infrastructure-as-Code using Azure Bicep to deploy Azure Functions for PowerShell on Linux OS.