Use Azure Devops variable in azure-pipelines.yml powershell script - powershell

Question

I think I may be approaching this the wrong way. I have an azure-pipelines.yml file where I am deploying infrastructure through this pipeline using Terraform. So far, the pipeline installs Terraform in the environment with no issue. I am trying to run terraform init using a Powershell script, and am running into an error. Within the Powershell script command I am trying to reference a pipeline variable for access_key and secret_key. When executing the pipeline, I am getting the error no valid credential sources for S3 Backend found. This is happening, most likely, because I am referencing the variables I have set incorrectly. I have also set the variables in my Terraform variables file, but I think that may not be necessary since I am trying to read in from the pipeline variables. Below is the code for azure-pipelines.yml and the error I am getting in the pipeline output. Any advice would be appreciated.
azure-pipelines.yml
trigger:
- master
pool:
vmImage: ubuntu-latest
stages:
- stage: TerraformInstall
displayName: Terraform
jobs:
- job: InstallTerraform
displayName: Install Terraform
steps:
- task: charleszipp.azure-pipelines-tasks-terraform.azure-pipelines-tasks-terraform-installer.TerraformInstaller#0
- stage: Init
displayName: Init
jobs:
- job: init
displayName: Terraform init
steps:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: 'terraform init -var access_key=${env:ACCESS_KEY} -var secret_key=${env:SECRET_KEY}'
Error
==============================================================================
Task : PowerShell
Description : Run a PowerShell script on Linux, macOS, or Windows
Version : 2.200.0
Author : Microsoft Corporation
Help : https://learn.microsoft.com/azure/devops/pipelines/tasks/utility/powershell
==============================================================================
Generating script.
========================== Starting Command Output ===========================
/usr/bin/pwsh -NoLogo -NoProfile -NonInteractive -Command . '/home/vsts/work/_temp/6e333d67-4373-4ae7-bc4b-96cc38572961.ps1'
Initializing the backend...
╷
│ Error: error configuring S3 Backend: no valid credential sources for S3 Backend found.
│
│ Please see https://www.terraform.io/docs/language/settings/backends/s3.html
│ for more information about providing credentials.
│
│ Error: NoCredentialProviders: no valid providers in chain. Deprecated.
│ For verbose messaging see aws.Config.CredentialsChainVerboseErrors
│
│
│
╵
##[error]PowerShell exited with code '1'.
Finishing: PowerShell

Answer 1

Without knowing more about how your variables are set it's hard to give a complete solution.
First, I don't think the Terraform CLI command Init accepts input variables (Correct me if I'm wrong). Just making a guess here, you're passing ACCESS_KEY and SECRET_KEY to be used with your Terraform backend provider. If that's the case, see this StackOver flow answer on how to do that. To summarize what that answer says
Create a separate .tfvars file that stores the variables that will be used for your backend provider
Use that .tfvars file with your Terraform Init like so:
terraform init -backend-config=backend.tfvars
Terraform aside, If you're using Azure DevOps Library variable groups, you can pass the variables to your script using the example below. Again, I don't think this will help you initialize your Terraform.
Note: You may need to play with the quotes depending on the OS of your agent.
This example assumes you have created an ADO library variable group named YourVariableGroupNameHere and have created two variables in that group named ACCESS_KEY and SECRET_KEY.
- stage: Init
displayName: Init
jobs:
- job: init
variables:
- group: YourVariableGroupNameHere
displayName: Terraform init
steps:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: 'terraform init -var access_key=$(ACCESS_KEY) -var secret_key=$(SECRET_KEY)'