feat: add IAM auth support, which is required for stack config templa…

…ting as of atmos 1.18.2.

action.yml

@@ -112,6 +112,11 @@ runs:
         echo "terraform-version=$(atmos describe config -f json | jq -r '.integrations.github.gitops["terraform-version"]')" >> $GITHUB_OUTPUT      
         echo "group-by=$(atmos describe config -f json | jq -r '.integrations.github.gitops.matrix["group-by"]')" >> $GITHUB_OUTPUT
         echo "sort-by=$(atmos describe config -f json | jq -r '.integrations.github.gitops.matrix["sort-by"]')" >> $GITHUB_OUTPUT
+        echo "aws-region=$(atmos describe config -f json | jq -r '.integrations.github.gitops["artifact-storage"].region')" >> $GITHUB_OUTPUT
+        echo "terraform-state-role=$(atmos describe config -f json | jq -r '.integrations.github.gitops["artifact-storage"].role')" >> $GITHUB_OUTPUT
+        echo "terraform-state-table=$(atmos describe config -f json | jq -r '.integrations.github.gitops["artifact-storage"].table')" >> $GITHUB_OUTPUT
+        echo "terraform-state-bucket=$(atmos describe config -f json | jq -r '.integrations.github.gitops["artifact-storage"].bucket')" >> $GITHUB_OUTPUT        
+        echo "terraform-plan-role=$(atmos describe config -f json | jq -r '.integrations.github.gitops.role.plan')" >> $GITHUB_OUTPUT
 
     - name: Install Terraform
       if: ${{ steps.config.outputs.terraform-version != '' && steps.config.outputs.terraform-version != 'null' }}
@@ -143,6 +148,14 @@ runs:
       run: git checkout ${{ inputs.base-ref }}
       working-directory: base-ref
 
+    - name: Configure Plan AWS Credentials
+      uses: aws-actions/configure-aws-credentials@v4.0.2
+      with:
+        aws-region: ${{ steps.config.outputs.aws-region }}
+        role-to-assume: ${{ steps.config.outputs.terraform-plan-role }}
+        role-session-name: "atmos-terraform-plan-gitops"
+        mask-aws-account-id: "no"
+
     - name: atmos affected stacks for atmos pro
       id: affected-pro
       if: ${{ inputs.atmos-pro-upload == 'true' }}