feat: handle .terraform cache

plan/action.yml

@@ -0,0 +1,43 @@
+name: Terraform Plan
+description: Run terraform plan and publish the plan as an artifact named "terraform-plan"
+
+inputs:
+  working-directory:
+    description: Directory containing the Terraform configuration
+    required: false
+    default: "."
+
+runs:
+  using: composite
+  steps:
+    - name: Setup Terraform
+      uses: hashicorp/setup-terraform@5e8dbf3c6d9deaf4193ca7a8fb23f2ac83bb6c85 # v4.0.0
+
+    - name: Cache Terraform providers
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
+      with:
+        path: ${{ inputs.working-directory }}/.terraform
+        key: terraform-${{ hashFiles(format('{0}/.terraform.lock.hcl', inputs.working-directory)) }}
+        restore-keys: terraform-
+
+    - name: Terraform Init
+      shell: bash
+      working-directory: ${{ inputs.working-directory }}
+      run: terraform init
+
+    - name: Terraform Validate
+      shell: bash
+      working-directory: ${{ inputs.working-directory }}
+      run: terraform validate
+
+    - name: Terraform Plan
+      shell: bash
+      working-directory: ${{ inputs.working-directory }}
+      run: terraform plan -out=tfplan
+
+    - name: Upload plan artifact
+      uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
+      with:
+        name: terraform-plan
+        path: ${{ inputs.working-directory }}/tfplan
+        retention-days: 5