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Quickstart: Create and deploy Azure Functions resources using Bicep

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In this article, you use Bicep to create a function app in a Flex Consumption plan in Azure, along with its required Azure resources. The function app provides a serverless execution context for your function code executions. The app uses Microsoft Entra ID with managed identities to connect to other Azure resources.

Completing this quickstart incurs a small cost of a few USD cents or less in your Azure account.

Bicep is a domain-specific language (DSL) that uses declarative syntax to deploy Azure resources. It provides concise syntax, reliable type safety, and support for code reuse. Bicep offers the best authoring experience for your infrastructure-as-code solutions in Azure.

After you create the function app, you can deploy your Azure Functions project code to that app. A final code deployment step is outside the scope of this quickstart article.

Prerequisites

Azure account

Before you begin, you must have an Azure account with an active subscription. Create an account for free.

Review the Bicep file

The Bicep file used in this quickstart is from an Azure Quickstart Template.

/* This Bicep file creates a function app running in a Flex Consumption plan 
that connects to Azure Storage by using managed identities with Microsoft Entra ID. */

//********************************************
// Parameters
//********************************************

@description('Primary region for all Azure resources.')
@minLength(1)
param location string = resourceGroup().location 

@description('Language runtime used by the function app.')
@allowed(['dotnet-isolated','python','java', 'node', 'powerShell'])
param functionAppRuntime string = 'dotnet-isolated' //Defaults to .NET isolated worker

@description('Target language version used by the function app.')
@allowed(['3.10','3.11', '7.4', '8.0', '9.0', '10', '11', '17', '20'])
param functionAppRuntimeVersion string = '8.0' //Defaults to .NET 8.

@description('The maximum scale-out instance count limit for the app.')
@minValue(40)
@maxValue(1000)
param maximumInstanceCount int = 100

@description('The memory size of instances used by the app.')
@allowed([2048,4096])
param instanceMemoryMB int = 2048

@description('A unique token used for resource name generation.')
@minLength(3)
param resourceToken string = toLower(uniqueString(subscription().id, location))

@description('A globally unigue name for your deployed function app.')
param appName string = 'func-${resourceToken}'

//********************************************
// Variables
//********************************************

// Generates a unique container name for deployments.
var deploymentStorageContainerName = 'app-package-${take(appName, 32)}-${take(resourceToken, 7)}'

// Key access to the storage account is disabled by default 
var storageAccountAllowSharedKeyAccess = false

// Define the IDs of the roles we need to assign to our managed identities.
var storageBlobDataOwnerRoleId  = 'b7e6dc6d-f1e8-4753-8033-0f276bb0955b'
var storageBlobDataContributorRoleId = 'ba92f5b4-2d11-453d-a403-e96b0029c9fe'
var storageQueueDataContributorId = '974c5e8b-45b9-4653-ba55-5f855dd0fb88'
var storageTableDataContributorId = '0a9a7e1f-b9d0-4cc4-a60d-0319b160aaa3'
var monitoringMetricsPublisherId = '3913510d-42f4-4e42-8a64-420c390055eb'

//********************************************
// Azure resources required by your function app.
//********************************************

resource logAnalytics 'Microsoft.OperationalInsights/workspaces@2023-09-01' = {
  name: 'log-${resourceToken}'
  location: location
  properties: any({
    retentionInDays: 30
    features: {
      searchVersion: 1
    }
    sku: {
      name: 'PerGB2018'
    }
  })
}

resource applicationInsights 'Microsoft.Insights/components@2020-02-02' = {
  name: 'appi-${resourceToken}'
  location: location
  kind: 'web'
  properties: {
    Application_Type: 'web'
    WorkspaceResourceId: logAnalytics.id
    DisableLocalAuth: true
  }
}

resource storage 'Microsoft.Storage/storageAccounts@2023-05-01' = {
  name: 'st${resourceToken}'
  location: location
  kind: 'StorageV2'
  sku: { name: 'Standard_LRS' }
  properties: {
    accessTier: 'Hot'
    allowBlobPublicAccess: false
    allowSharedKeyAccess: storageAccountAllowSharedKeyAccess
    dnsEndpointType: 'Standard'
    minimumTlsVersion: 'TLS1_2'
    networkAcls: {
      bypass: 'AzureServices'
      defaultAction: 'Allow'
    }
    publicNetworkAccess: 'Enabled'
  }
  resource blobServices 'blobServices' = {
    name: 'default'
    properties: {
      deleteRetentionPolicy: {}
    }
    resource deploymentContainer 'containers' = {
      name: deploymentStorageContainerName
      properties: {
        publicAccess: 'None'
      }
    }
  }
}

resource userAssignedIdentity 'Microsoft.ManagedIdentity/userAssignedIdentities@2023-01-31' = {
  name: 'uai-data-owner-${resourceToken}'
  location: location
}

resource roleAssignmentBlobDataOwner 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
  name: guid(subscription().id, storage.id, userAssignedIdentity.id, 'Storage Blob Data Owner')
  scope: storage
  properties: {
    roleDefinitionId: subscriptionResourceId('Microsoft.Authorization/roleDefinitions', storageBlobDataOwnerRoleId)
    principalId: userAssignedIdentity.properties.principalId
    principalType: 'ServicePrincipal'
  }
}

resource roleAssignmentBlob 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
  name: guid(subscription().id, storage.id, userAssignedIdentity.id, 'Storage Blob Data Contributor')
  scope: storage
  properties: {
    roleDefinitionId: subscriptionResourceId('Microsoft.Authorization/roleDefinitions', storageBlobDataContributorRoleId)
    principalId: userAssignedIdentity.properties.principalId
    principalType: 'ServicePrincipal'
  }
}

resource roleAssignmentQueueStorage 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
  name: guid(subscription().id, storage.id, userAssignedIdentity.id, 'Storage Queue Data Contributor')
  scope: storage
  properties: {
    roleDefinitionId: subscriptionResourceId('Microsoft.Authorization/roleDefinitions', storageQueueDataContributorId)
    principalId: userAssignedIdentity.properties.principalId
    principalType: 'ServicePrincipal'
  }
}

resource roleAssignmentTableStorage 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
  name: guid(subscription().id, storage.id, userAssignedIdentity.id, 'Storage Table Data Contributor')
  scope: storage
  properties: {
    roleDefinitionId: subscriptionResourceId('Microsoft.Authorization/roleDefinitions', storageTableDataContributorId)
    principalId: userAssignedIdentity.properties.principalId
    principalType: 'ServicePrincipal'
  }
}

resource roleAssignmentAppInsights 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
  name: guid(subscription().id, applicationInsights.id, userAssignedIdentity.id, 'Monitoring Metrics Publisher')
  scope: applicationInsights
  properties: {
    roleDefinitionId: subscriptionResourceId('Microsoft.Authorization/roleDefinitions', monitoringMetricsPublisherId)
    principalId: userAssignedIdentity.properties.principalId
    principalType: 'ServicePrincipal'
  }
}

//********************************************
// Function app and Flex Consumption plan definitions
//********************************************

resource appServicePlan 'Microsoft.Web/serverfarms@2024-04-01' = {
  name: 'plan-${resourceToken}'
  location: location
  kind: 'functionapp'
  sku: {
    tier: 'FlexConsumption'
    name: 'FC1'
  }
  properties: {
    reserved: true
  }
}

resource functionApp 'Microsoft.Web/sites@2024-04-01' = {
  name: appName
  location: location
  kind: 'functionapp,linux'
  identity: {
    type: 'UserAssigned'
    userAssignedIdentities: {
      '${userAssignedIdentity.id}':{}
      }
    }
  properties: {
    serverFarmId: appServicePlan.id
    httpsOnly: true
    siteConfig: {
      minTlsVersion: '1.2'
    }
    functionAppConfig: {
      deployment: {
        storage: {
          type: 'blobContainer'
          value: '${storage.properties.primaryEndpoints.blob}${deploymentStorageContainerName}'
          authentication: {
            type: 'UserAssignedIdentity'
            userAssignedIdentityResourceId: userAssignedIdentity.id
          }
        }
      }
      scaleAndConcurrency: {
        maximumInstanceCount: maximumInstanceCount
        instanceMemoryMB: instanceMemoryMB
      }
      runtime: { 
        name: functionAppRuntime
        version: functionAppRuntimeVersion
      }
    }
  }
  resource configAppSettings 'config' = {
    name: 'appsettings'
    properties: {
        AzureWebJobsStorage__accountName: storage.name
        AzureWebJobsStorage__credential : 'managedidentity'
        AzureWebJobsStorage__clientId: userAssignedIdentity.properties.clientId
        APPLICATIONINSIGHTS_INSTRUMENTATIONKEY: applicationInsights.properties.InstrumentationKey
        APPLICATIONINSIGHTS_AUTHENTICATION_STRING: 'ClientId=${userAssignedIdentity.properties.clientId};Authorization=AAD'
      }
  }
}

This deployment file creates these Azure resources needed by a function app that securely connects to Azure services:

Deployment considerations:

  • The storage account is used to store important app data, including the application code deployment package. This deployment creates a storage account that is accessed using Microsoft Entra ID authentication and managed identities. Identity access is granted on a least-permissions basis.
  • The Bicep file defaults to creating a C# app that uses .NET 8 in an isolated process. For other languages, use the functionAppRuntime and functionAppRuntimeVersion parameters to specify the specific language and version on which to run your app. Make sure to select your programming language at the top of the article.

Deploy the Bicep file

  1. Save the Bicep file as main.bicep to your local computer.

  2. Deploy the Bicep file using either Azure CLI or Azure PowerShell.

    az group create --name exampleRG --location <SUPPORTED_REGION>
az deployment group create --resource-group exampleRG --template-file main.bicep --parameters functionAppRuntime=dotnet-isolated functionAppRuntimeVersion=8.0

    az group create --name exampleRG --location <SUPPORTED_REGION>
az deployment group create --resource-group exampleRG --template-file main.bicep --parameters functionAppRuntime=java functionAppRuntimeVersion=17

    az group create --name exampleRG --location <SUPPORTED_REGION>
az deployment group create --resource-group exampleRG --template-file main.bicep --parameters functionAppRuntime=node functionAppRuntimeVersion=20

    az group create --name exampleRG --location <SUPPORTED_REGION>
az deployment group create --resource-group exampleRG --template-file main.bicep --parameters functionAppRuntime=python functionAppRuntimeVersion=3.11

    az group create --name exampleRG --location <SUPPORTED_REGION>
az deployment group create --resource-group exampleRG --template-file main.bicep --parameters functionAppRuntime=powerShell functionAppRuntimeVersion=7.4

    In this example, replace <SUPPORTED_REGION> with a region that supports the Flex Consumption plan.

    When the deployment finishes, you should see a message indicating the deployment succeeded.

Validate the deployment

Use Azure CLI or Azure PowerShell to validate the deployment.

az resource list --resource-group exampleRG

Visit function app welcome page

  1. Use the output from the previous validation step to retrieve the unique name created for your function app.

  2. Open a browser and enter the following URL: <https://<appName.azurewebsites.net>. Make sure to replace <\appName> with the unique name created for your function app.

    When you visit the URL, you should see a page like this:

    Function app welcome page

Clean up resources

Now that you have deployed a function app and related resources to Azure, can continue to the next step of publishing project code to your app. Otherwise, use these commands to delete the resources, when you no longer need them.

az group delete --name exampleRG

You can also remove resources by using the Azure portal.

Next steps

You can now deploy a code project to the function app resources you created in Azure.

You can create, verify, and deploy a code project to your new function app from these local environments: