Terraform authentication inherits Azure Pipeline Service Connection credentials

terraform-authentication-azure-pipeline.yml

- task: AzureCLI@2
  displayName: 'Terraform init'
  inputs:
    azureSubscription: '$(subscriptionConnection)'
    scriptType: pscore
    scriptLocation: inlineScript
    inlineScript: |
      # Propagate pipeline Service Principal as Terraform variables
      $env:ARM_CLIENT_ID       ??= $env:servicePrincipalId
      $env:ARM_CLIENT_SECRET   ??= $env:servicePrincipalKey
      $env:ARM_TENANT_ID       ??= $env:tenantId
      # Propagate from Azure CLI context
      $env:ARM_TENANT_ID       ??= $(az account show --query tenantId -o tsv)
      $env:ARM_SUBSCRIPTION_ID ??= $(az account show --query id -o tsv)              

      # Put Terraform commands after this line
    addSpnToEnvironment: true
    useGlobalConfig: true
    failOnStandardError: true
    powerShellIgnoreLASTEXITCODE: false
    workingDirectory: '$(terraformDirectory)'