Merge pull request #16782 from hashicorp/jbardin/output-warning

Add flag to opt out of module output errors

config/config.go

@@ -859,7 +859,6 @@ func (c *Config) Validate() tfdiags.Diagnostics {
 					}
 				}
 			}
-
 		}
 	}
 

config/config_test.go

@@ -862,3 +862,22 @@ func TestConfigModuleProviders(t *testing.T) {
 		t.Fatalf("exptected providers %#v, got providers %#v", expected, got)
 	}
 }
+
+func TestValidateOutputErrorWarnings(t *testing.T) {
+	// TODO: remove this in 0.12
+	c := testConfig(t, "output-warnings")
+
+	diags := c.Validate()
+	if diags.HasErrors() {
+		t.Fatal("config should not have errors:", diags)
+	}
+	if len(diags) != 2 {
+		t.Fatalf("should have 2 warnings, got %d:\n%s", len(diags), diags)
+	}
+
+	// this fixture has no explicit count, and should have no warning
+	c = testConfig(t, "output-no-warnings")
+	if err := c.Validate(); err != nil {
+		t.Fatal("config should have no warnings or errors")
+	}
+}

config/test-fixtures/output-no-warnings/main.tf

@@ -0,0 +1,6 @@
+resource "test_instance" "foo" {
+}
+
+output "foo_id" {
+  value = "${test_instance.foo.id}"
+}

config/test-fixtures/output-warnings/main.tf

@@ -0,0 +1,24 @@
+locals {
+  "count" = 1
+}
+
+resource "test_instance" "foo" {
+  count = "${local.count}"
+}
+
+output "foo_id" {
+  value = "${test_instance.foo.id}"
+}
+
+variable "condition" {
+  default = "true"
+}
+
+resource "test_instance" "bar" {
+  count = "${var.condition ? 1 : 0}"
+}
+
+
+output "bar_id" {
+  value = "${test_instance.bar.id}"
+}

terraform/eval_output.go

@@ -68,9 +68,9 @@ func (n *EvalWriteOutput) Eval(ctx EvalContext) (interface{}, error) {
 
 	// handling the interpolation error
 	if err != nil {
-		if n.ContinueOnErr {
+		if n.ContinueOnErr || flagWarnOutputErrors {
 			log.Printf("[ERROR] Output interpolation %q failed: %s", n.Name, err)
-			// if we're continueing, make sure the output is included, and
+			// if we're continuing, make sure the output is included, and
 			// marked as unknown
 			mod.Outputs[n.Name] = &OutputState{
 				Type:  "string",

terraform/features.go

@@ -1,3 +1,7 @@
 package terraform
 
+import "os"
+
 // This file holds feature flags for the next release
+
+var flagWarnOutputErrors = os.Getenv("TF_WARN_OUTPUT_ERRORS") != ""