"defaults" property for terraform_remote_state

This allows providing default values for keys that might not be set in the retrieved state.

terraform/data_source_state.go

@@ -37,6 +37,11 @@ func dataSourceRemoteState() *schema.Resource {
 				Optional: true,
 			},
 
+			"defaults": {
+				Type:     schema.TypeMap,
+				Optional: true,
+			},
+
 			"environment": {
 				Type:     schema.TypeString,
 				Optional: true,
@@ -88,25 +93,29 @@ func dataSourceRemoteStateRead(d *schema.ResourceData, meta interface{}) error {
 	if err := state.RefreshState(); err != nil {
 		return err
 	}
-
 	d.SetId(time.Now().UTC().String())
 
 	outputMap := make(map[string]interface{})
 
+	defaults := d.Get("defaults").(map[string]interface{})
+	for key, val := range defaults {
+		outputMap[key] = val
+	}
+
 	remoteState := state.State()
 	if remoteState.Empty() {
 		log.Println("[DEBUG] empty remote state")
-		return nil
-	}
-
+	} else {
 		for key, val := range remoteState.RootModule().Outputs {
 			outputMap[key] = val.Value
 		}
+	}
 
 	mappedOutputs := remoteStateFlatten(outputMap)
 
 	for key, val := range mappedOutputs {
 		d.UnsafeSetFieldRaw(key, val)
 	}
+
 	return nil
 }

terraform/data_source_state_test.go

@@ -63,6 +63,38 @@ func TestState_complexOutputs(t *testing.T) {
 	})
 }
 
+func TestEmptyState_defaults(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		PreCheck:  func() { testAccPreCheck(t) },
+		Providers: testAccProviders,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccEmptyState_defaults,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckStateValue(
+						"data.terraform_remote_state.foo", "foo", "bar"),
+				),
+			},
+		},
+	})
+}
+
+func TestState_defaults(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		PreCheck:  func() { testAccPreCheck(t) },
+		Providers: testAccProviders,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccEmptyState_defaults,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckStateValue(
+						"data.terraform_remote_state.foo", "foo", "bar"),
+				),
+			},
+		},
+	})
+}
+
 func testAccCheckStateValue(id, name, value string) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
 		rs, ok := s.RootModule().Resources[id]
@@ -109,3 +141,29 @@ resource "terraform_remote_state" "foo" {
 		path = "./test-fixtures/complex_outputs.tfstate"
 	}
 }`
+
+const testAccEmptyState_defaults = `
+data "terraform_remote_state" "foo" {
+	backend = "local"
+
+	config {
+		path = "./test-fixtures/empty.tfstate"
+	}
+
+	defaults {
+		foo = "bar"
+	}
+}`
+
+const testAccState_defaults = `
+data "terraform_remote_state" "foo" {
+	backend = "local"
+
+	config {
+		path = "./test-fixtures/basic.tfstate"
+	}
+
+	defaults {
+		foo = "not bar"
+	}
+}`

website/docs/d/remote_state.html.md

@@ -33,6 +33,7 @@ The following arguments are supported:
 * `backend` - (Required) The remote backend to use.
 * `environment` - (Optional) The Terraform environment to use.
 * `config` - (Optional) The configuration of the remote backend.
+* `defaults` - (Optional) default value for outputs in case state file is empty or it does not have the output.
  * Remote state config docs can be found [here](/docs/backends/types/terraform-enterprise.html)
 
 ## Attributes Reference