Terraform authentication re-uses GitHub Azure Action credentials

terraform-authentication-github-actions.yml

- name: Get Azure CLI
  uses: azure/login@v1
  with:
    creds: ${{ secrets.AZURE_CREDENTIALS }}

- name: Get Terraform
  uses: hashicorp/setup-terraform@v1
  with:
    terraform_version: 'latest'
    terraform_wrapper: false

- name: Prepare environment variables
  env:
    AZURE_CREDENTIALS: ${{ secrets.AZURE_CREDENTIALS }}
  run: | 
    # Parse Azure secret into Terraform variables
    $servicePrincipal = ($env:AZURE_CREDENTIALS | ConvertFrom-Json)
    $env:ARM_CLIENT_ID = $servicePrincipal.clientId
    $env:ARM_CLIENT_SECRET = $servicePrincipal.clientSecret
    $env:ARM_SUBSCRIPTION_ID = $servicePrincipal.subscriptionId
    $env:ARM_TENANT_ID = $servicePrincipal.tenantId

    # Save environment variable setup for subsequent steps
    Get-ChildItem -Path Env: -Recurse -Include ARM_*,TF_VAR_* | ForEach-Object {Write-Output "$($_.Name)=$($_.Value)"} >> $env:GITHUB_ENV
  shell: pwsh

- name: Terraform Init
  run: terraform init
  shell: pwsh

Hi, here is the same for bash. In case, someone needs it. It requires jq to be installed. https://gist.github.com/tp199314/c5a37eb3962b48a69d8275a41c6c7adb