Export Terraform output as GitHub Action step output

terraform-output-github-action.yml

- name: Terraform Apply
  id: terraform-apply
  run: | 
    Set-Location (Join-Path $env:GITHUB_WORKSPACE terraform) # Task does not support 'working-directory' property
    terraform apply -auto-approve

    # Export Terraform output as step output
    $terraformOutput = (terraform output -json | ConvertFrom-Json -AsHashtable)     
    foreach ($key in $terraformOutput.Keys) {
      $outputVariableValue = $terraformOutput[$key].value
      Write-Output "::set-output name=${key}::${outputVariableValue}"
      Write-Output "TF_OUT_${key}=${outputVariableValue}" >> $env:GITHUB_ENV
    } 
  shell: pwsh