chore: post terraform plan summary as PR comment

Author: jgravois

.github/workflows/terraform-plan.yml

@@ -8,8 +8,9 @@ on:
       - ".github/workflows/terraform-plan.yml"
 
 permissions:
-  id-token: write
   contents: read
+  id-token: write
+  pull-requests: write
 
 jobs:
   terraform-plan:
@@ -43,4 +44,11 @@ jobs:
           TF_VAR_CONTAINER_TAG: ${{ github.sha }}
           TF_VAR_DEVSECOPS_OBJECT_ID: ${{ secrets.TF_VAR_DEVSECOPS_OBJECT_ID }}
           TF_VAR_ENGINEERING_GROUP_OBJECT_ID: ${{ secrets.TF_VAR_ENGINEERING_GROUP_OBJECT_ID }}
-        run: terraform plan -lock-timeout=5m
+        run: terraform plan -out=tfplan -lock-timeout=5m
+
+      - name: Summarize plan in PR comment
+        uses: borchero/terraform-plan-comment@2d41e908725447b1677913001dfb92fa7010c025 # v3.1.0
+        with:
+          planfile: tfplan
+          token: ${{ github.token }}
+          working-directory: terraform