Fix to not return err when instance is already terminated

aws/resource_aws_instance.go

@@ -1925,9 +1925,16 @@ func awsTerminateInstance(conn *ec2.EC2, id string, timeout time.Duration) error
 		InstanceIds: []*string{aws.String(id)},
 	}
 	if _, err := conn.TerminateInstances(req); err != nil {
+		if ec2err, ok := err.(awserr.Error); ok && ec2err.Code() == "InvalidInstanceID.NotFound" {
+			return nil
+		}
 		return fmt.Errorf("Error terminating instance: %s", err)
 	}
 
+	return waitForInstanceDeletion(conn, id, timeout)
+}
+
+func waitForInstanceDeletion(conn *ec2.EC2, id string, timeout time.Duration) error {
 	log.Printf("[DEBUG] Waiting for instance (%s) to become terminated", id)
 
 	stateConf := &resource.StateChangeConf{

aws/resource_aws_instance_test.go

@@ -1942,6 +1942,27 @@ func TestAccAWSInstance_creditSpecification_unlimitedCpuCredits_t2Tot3Taint(t *t
 	})
 }
 
+func TestAccAWSInstance_disappears(t *testing.T) {
+	var conf ec2.Instance
+	rInt := acctest.RandInt()
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckInstanceDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccInstanceConfig(rInt),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckInstanceExists("aws_instance.foo", &conf),
+					testAccCheckInstanceDisappears(&conf),
+				),
+				ExpectNonEmptyPlan: true,
+			},
+		},
+	})
+}
+
 func TestAccAWSInstance_UserData_EmptyStringToUnspecified(t *testing.T) {
 	var instance ec2.Instance
 	rInt := acctest.RandInt()
@@ -2075,6 +2096,22 @@ func testAccCheckInstanceExistsWithProvider(n string, i *ec2.Instance, providerF
 	}
 }
 
+func testAccCheckInstanceDisappears(conf *ec2.Instance) resource.TestCheckFunc {
+	return func(s *terraform.State) error {
+		conn := testAccProvider.Meta().(*AWSClient).ec2conn
+
+		params := &ec2.TerminateInstancesInput{
+			InstanceIds: []*string{conf.InstanceId},
+		}
+
+		if _, err := conn.TerminateInstances(params); err != nil {
+			return err
+		}
+
+		return waitForInstanceDeletion(conn, *conf.InstanceId, 10*time.Minute)
+	}
+}
+
 func TestInstanceTenancySchema(t *testing.T) {
 	actualSchema := resourceAwsInstance().Schema["tenancy"]
 	expectedSchema := &schema.Schema{