Publish Azure Static Web Apps with Bicep and Azure DevOps

This post demonstrates how to deploy Azure Static Web Apps using Bicep and Azure DevOps. It includes a few workarounds for the "Provider is invalid. Cannot change the Provider. Please detach your static site first if you wish to use to another deployment provider." issue.

Bicep template

The first thing we're going to do is create a folder where our Bicep file for deploying our Azure Static Web App will live:

mkdir infra/static-web-app -p

Then we'll create a main.bicep file:

param repositoryUrl string
param repositoryBranch string

param location string = 'westeurope'
param skuName string = 'Free'
param skuTier string = 'Free'

param appName string

resource staticWebApp 'Microsoft.Web/staticSites@2020-12-01' = {
  name: appName
  location: location
  sku: {
    name: skuName
    tier: skuTier
  }
  properties: {
    // The provider, repositoryUrl and branch fields are required for successive deployments to succeed
    // for more details see: https://github.com/Azure/static-web-apps/issues/516
    provider: 'DevOps'
    repositoryUrl: repositoryUrl
    branch: repositoryBranch
    buildProperties: {
      skipGithubActionWorkflowGeneration: true
    }
  }
}

output deployment_token string = listSecrets(staticWebApp.id, staticWebApp.apiVersion).properties.apiKey

There's some things to draw attention to in the code above:

1. The provider, repositoryUrl and branch fields are required for successive deployments to succeed. In our case we're deploying via Azure DevOps and so our provider is 'DevOps'. For more details, look at this issue.
2. We're creating a deployment_token which we'll need in order that we can deploy into the Azure Static Web App resource.

Static Web App

In order that we can test out Azure Static Web Apps, what we need is a static web app. You could use pretty much anything here; we're going to use Docusaurus. We'll execute this single command:

npx @docusaurus/init@latest init static-web-app classic

Which will scaffold a Docusaurus site in a folder named static-web-app. We don't need to change it any further; let's just see if we can deploy it.

Azure Pipeline

We're going to add an azure-pipelines.yml file which Azure DevOps can use to power a pipeline:

trigger:
  - main

pool:
  vmImage: ubuntu-latest

steps:
  - checkout: self
    submodules: true

  - bash: az bicep build --file infra/static-web-app/main.bicep
    displayName: 'Compile Bicep to ARM'

  - task: AzureResourceManagerTemplateDeployment@3
    name: DeployStaticWebAppInfra
    displayName: Deploy Static Web App infra
    inputs:
      deploymentScope: Resource Group
      azureResourceManagerConnection: $(serviceConnection)
      subscriptionId: $(subscriptionId)
      action: Create Or Update Resource Group
      resourceGroupName: $(azureResourceGroup)
      location: $(location)
      templateLocation: Linked artifact
      csmFile: 'infra/static-web-app/main.json' # created by bash script
      overrideParameters: >-
        -repositoryUrl $(repo)
        -repositoryBranch $(Build.SourceBranchName)
        -appName $(staticWebAppName)
      deploymentMode: Incremental
      deploymentOutputs: deploymentOutputs

  - task: PowerShell@2
    name: 'SetDeploymentOutputVariables'
    displayName: 'Set Deployment Output Variables'
    inputs:
      targetType: inline
      script: |
        $armOutputObj = '$(deploymentOutputs)' | ConvertFrom-Json
        $armOutputObj.PSObject.Properties | ForEach-Object {
          $keyname = $_.Name
          $value = $_.Value.value

          # Creates a standard pipeline variable
          Write-Output "##vso[task.setvariable variable=$keyName;issecret=true]$value"

          # Display keys in pipeline
          Write-Output "output variable: $keyName"
        }
      pwsh: true

  - task: AzureStaticWebApp@0
    name: DeployStaticWebApp
    displayName: Deploy Static Web App
    inputs:
      app_location: 'static-web-app'
      # api_location: 'api' # we don't have an API
      output_location: 'build'
      azure_static_web_apps_api_token: $(deployment_token) # captured from deploymentOutputs

When the pipeline is run, it does the following:

1. Compiles our Bicep into an ARM template
2. Deploys the compiled ARM template to Azure
3. Captures the deployment outputs (essentially the deployment_token) and converts them into variables to use in the pipeline
4. Deploys our Static Web App using the deployment_token

The pipeline depends upon a number of variables:

• azureResourceGroup - the name of your resource group in Azure where the app will be deployed
• location - where your app is deployed, eg northeurope
• repo - the URL of your repository in Azure DevOps, eg https://dev.azure.com/johnnyreilly/_git/azure-static-web-apps
• serviceConnection - the name of your AzureRM service connection in Azure DevOps
• staticWebAppName - the name of your static web app, eg azure-static-web-apps-johnnyreilly
• subscriptionId - your Azure subscription id from the Azure Portal

A successful pipeline looks something like this:

What you might notice is that the AzureStaticWebApp is itself installing and building our application. This is handled by Microsoft Oryx. The upshot of this is that we don't need to manually run npm install and npm build ourselves; the AzureStaticWebApp task will take care of it for us.

Finally, let's see if we've deployed something successfully…

We have! It's worth noting that you'll likely want to give your Azure Static Web App a lovelier URL, and perhaps even put it behind Azure Front Door as well.

Provider is invalid workaround 2

Shane Neff was attempting to follow the instructions in this post and encountered issues. He shared his struggles with me as he encountered the "Provider is invalid. Cannot change the Provider. Please detach your static site first if you wish to use to another deployment provider." issue.

He was good enough to share his solution as well, which is inserting this task at the start of the pipeline (before the az bicep build step):

- task: AzureCLI@2
  inputs:
    azureSubscription: '<name of your service connection>'
    scriptType: 'bash'
    scriptLocation: 'inlineScript'
    inlineScript: 'az staticwebapp disconnect -n <name of your app>'

I haven't had the problems that Shane has had myself, but I wanted to share his fix for the people out there who almost certainly are bumping on this.