From e5223b4c49e608a0e8c2b5953e65b27ad2cc4275 Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro@pietroalbini.org>
Date: Fri, 3 Jan 2020 09:54:37 +0100
Subject: [PATCH] terraform: disable cloudfront root object for crates.io on
 staging

There is a concern that setting the default root object to index.html
for the crates.io webapp causes Fastboot to break:

    https://github.com/rust-lang/crates.io/pull/1937#issuecomment-570452017

This adds a temporary feature flag to remove the default root object
just from staging, without affecting production. After testing is done
the feature flag will have to be removed, either disabling or enabling
the root object both on staging and production.
---
 terraform/services.tf                            | 3 +++
 terraform/services/cratesio/cloudfront-webapp.tf | 2 +-
 terraform/services/cratesio/variables.tf         | 4 ++++
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/terraform/services.tf b/terraform/services.tf
index 39ea05cf..0c60059d 100644
--- a/terraform/services.tf
+++ b/terraform/services.tf
@@ -103,6 +103,7 @@ module "service_cratesio" {
   iam_prefix = "crates-io"
 
   logs_bucket = aws_s3_bucket.temp_logs_cratesio.bucket_domain_name
+  temp_flag_root_object = true
 }
 
 module "service_cratesio_staging" {
@@ -122,6 +123,8 @@ module "service_cratesio_staging" {
   webapp_origin_domain = "staging-crates-io.herokuapp.com"
 
   iam_prefix = "staging-crates-io"
+
+  temp_flag_root_object = false
 }
 
 module "service_docsrs" {
diff --git a/terraform/services/cratesio/cloudfront-webapp.tf b/terraform/services/cratesio/cloudfront-webapp.tf
index b2a54a8e..998cea8d 100644
--- a/terraform/services/cratesio/cloudfront-webapp.tf
+++ b/terraform/services/cratesio/cloudfront-webapp.tf
@@ -6,7 +6,7 @@ resource "aws_cloudfront_distribution" "webapp" {
   enabled             = true
   wait_for_deployment = false
   is_ipv6_enabled     = true
-  default_root_object = "index.html"
+  default_root_object = var.temp_flag_root_object ? "index.html" : null
   price_class         = "PriceClass_All"
 
   aliases = [var.webapp_domain_name]
diff --git a/terraform/services/cratesio/variables.tf b/terraform/services/cratesio/variables.tf
index 4732f5a8..f2caced7 100644
--- a/terraform/services/cratesio/variables.tf
+++ b/terraform/services/cratesio/variables.tf
@@ -36,3 +36,7 @@ variable "logs_bucket" {
   type        = string
   default     = null
 }
+
+variable "temp_flag_root_object" {
+  type = bool
+}