Azure Devops // Service Connection // Terraform // Yaml Pipeline -> Build Error

I have setup a whole bunch of files for deploying a simple VM, but trying to use the ADO Service Connection setup in the projec, avoiding to hardcode secrets, however after multiple tries still failing

Error: Error building ARM Config: obtain subscription() from Azure CLI: parsing json result from the Azure CLI: waiting for the Azure CLI: exit status 1: ERROR: Please run 'az login' to setup account

I was hoping to pass values from the ADO Service Connection into variables extracted from the pipe yaml file to the main.tf terraform file for authentication

main.tf extract

provider "azurerm" {
features {}

client_id       = ARM_CLIENT_ID
client_secret   = ARM_CLIENT_SECRET
tenant_id       = ARM_TENANT_ID
subscription_id = ARM_CLIENT_SUBSCRIPTION_ID
}

terraform-pipelines.yml extract

trigger:

- main

pool:
vmImage: 'ubuntu-latest'

variables:
KeyVault: "test-kv"
StorageAccount: "testtfstatedemostg"
ContainerName: "tfstate"
ResourceGroup: "test-rg"  
AzureRegion: "uksouth"  
vmCount: 1
vmNames: "vm01"
os_publisher: "Canonical"
os_offer: "UbuntuServer"
os_sku: "18.04-LTS"
os_version: "latest"

jobs:

- job: TerraformDeployment
  displayName: 'Terraform Deployment'
  steps:
  - task: UsePythonVersion@0
    inputs:
    versionSpec: '3.x'
    addToPath: true
    azureSubscription: "\<AzureDevops_Service_Connection_Name\>"
    scriptType: bash
    addSpnToEnvironment: true # this will add the required credentials to env vars
    useGlobalConfig: true
    scriptLocation: inlineScript
    inlineScript: |
    echo "##vso\[task.setvariable variable=ARM_TENANT_ID;\]$tenantId"
    echo "##vso\[task.setvariable variable=ARM_CLIENT_ID;\]$servicePrincipalId"
    echo "##vso\[task.setvariable variable=ARM_CLIENT_SECRET;\]$servicePrincipalKey"
    echo "##vso\[task.setvariable variable=ARM_CLIENT_SUBSCRIPTION_ID;\]$subscriptionId"

  - script: |
    #Install Terraform
    curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
    echo "deb \[signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg\] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list
    sudo apt-get update && sudo apt-get install terraform

    #Initialize Terraform
    cd $(Build.SourcesDirectory)
    terraform init

You are using the wrong task to get the credentials. The UsePythonVersion@0 task does not have the options to receive ARM service connection and run script.

The correct task you should use is AzureCLI@2. See below sample as refence.

    steps:
    - task: AzureCLI@2
      displayName: 'Get login Credentials'
      inputs:
        addSpnToEnvironment: true
        azureSubscription: MyArmConnection
        scriptType: bash
        scriptLocation: inlineScript
        inlineScript: |
          echo "##vso[task.setvariable variable=ARM_TENANT_ID]$tenantId"
          echo "##vso[task.setvariable variable=ARM_CLIENT_ID]$servicePrincipalId" 
          echo "##vso[task.setvariable variable=ARM_CLIENT_SECRET]$servicePrincipalKey"
    
    - bash: az login --service-principal --tenant $(ARM_TENANT_ID) --username $(ARM_CLIENT_ID) --password $(ARM_CLIENT_SECRET)
      displayName: 'Login Azure using az login'

Note:

This feature does not return the Azure Subscription Id.