feat: amplify custom headers configuration (#46)

* feat: amplify custom headers configuration

* additional readme exampel

README.md

@@ -27,7 +27,7 @@
 
 -->
 
-Terraform module to provision AWS Amplify apps, backend environments, branches, domain associations, and webhooks. 
+Terraform module to provision AWS Amplify apps, backend environments, branches, domain associations, and webhooks.
 
 
 > [!TIP]
@@ -121,6 +121,14 @@ module "amplify_app" {
     }
   ]
 
+  custom_headers = <<-EOT
+    customHeaders:
+      - pattern: '**'
+        headers:
+          - key: 'Strict-Transport-Security'
+            value: 'max-age=31536000; includeSubDomains'
+  EOT
+
   environment_variables = {
     ENV = "test"
   }
@@ -241,6 +249,7 @@ Available targets:
 | <a name="input_basic_auth_credentials"></a> [basic\_auth\_credentials](#input\_basic\_auth\_credentials) | The credentials for basic authorization for the Amplify app | `string` | `null` | no |
 | <a name="input_build_spec"></a> [build\_spec](#input\_build\_spec) | The [build specification](https://docs.aws.amazon.com/amplify/latest/userguide/build-settings.html) (build spec) for the Amplify app.<br/>If not provided then it will use the `amplify.yml` at the root of your project / branch. | `string` | `null` | no |
 | <a name="input_context"></a> [context](#input\_context) | Single object for setting entire context at once.<br/>See description of individual variables for details.<br/>Leave string and numeric variables as `null` to use default value.<br/>Individual variable settings (non-null) override settings in context object,<br/>except for attributes, tags, and additional\_tag\_map, which are merged. | `any` | <pre>{<br/>  "additional_tag_map": {},<br/>  "attributes": [],<br/>  "delimiter": null,<br/>  "descriptor_formats": {},<br/>  "enabled": true,<br/>  "environment": null,<br/>  "id_length_limit": null,<br/>  "label_key_case": null,<br/>  "label_order": [],<br/>  "label_value_case": null,<br/>  "labels_as_tags": [<br/>    "unset"<br/>  ],<br/>  "name": null,<br/>  "namespace": null,<br/>  "regex_replace_chars": null,<br/>  "stage": null,<br/>  "tags": {},<br/>  "tenant": null<br/>}</pre> | no |
+| <a name="input_custom_headers"></a> [custom\_headers](#input\_custom\_headers) | The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html | `string` | `""` | no |
 | <a name="input_custom_rules"></a> [custom\_rules](#input\_custom\_rules) | The custom rules to apply to the Amplify App | <pre>list(object({<br/>    condition = optional(string)<br/>    source    = string<br/>    status    = optional(string)<br/>    target    = string<br/>  }))</pre> | `[]` | no |
 | <a name="input_delimiter"></a> [delimiter](#input\_delimiter) | Delimiter to be used between ID elements.<br/>Defaults to `-` (hyphen). Set to `""` to use no delimiter at all. | `string` | `null` | no |
 | <a name="input_description"></a> [description](#input\_description) | The description for the Amplify app | `string` | `null` | no |

examples/complete/fixtures.us-east-2.tfvars

@@ -74,6 +74,15 @@ custom_rules = [
   }
 ]
 
+# Custom header, HTST to always block HTTP and always redirect to HTTPS
+custom_headers = <<-EOT
+  customHeaders:
+    - pattern: '**'
+      headers:
+        - key: 'Strict-Transport-Security'
+          value: 'max-age=31536000; includeSubDomains'
+EOT
+
 environment_variables = {
   ENV = "test"
 }

examples/complete/main.tf

@@ -26,6 +26,7 @@ module "amplify_app" {
   enable_branch_auto_deletion   = var.enable_branch_auto_deletion
   environment_variables         = var.environment_variables
   custom_rules                  = var.custom_rules
+  custom_headers                = var.custom_headers
   iam_service_role_enabled      = var.iam_service_role_enabled
   iam_service_role_arn          = var.iam_service_role_arn
   iam_service_role_actions      = var.iam_service_role_actions

examples/complete/variables.tf

@@ -110,6 +110,12 @@ variable "environment_variables" {
   default     = {}
 }
 
+variable "custom_headers" {
+  type        = string
+  description = "The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html"
+  default     = ""
+}
+
 variable "iam_service_role_arn" {
   type        = list(string)
   description = <<-EOT

main.tf

@@ -25,6 +25,7 @@ resource "aws_amplify_app" "default" {
   enable_basic_auth             = var.enable_basic_auth
   enable_branch_auto_build      = var.enable_branch_auto_build
   environment_variables         = var.environment_variables
+  custom_headers                = var.custom_headers
 
   iam_service_role_arn = local.iam_service_role_arn
 

variables.tf

@@ -136,6 +136,12 @@ variable "iam_service_role_actions" {
   nullable    = false
 }
 
+variable "custom_headers" {
+  type        = string
+  description = "The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html"
+  default     = ""
+}
+
 variable "custom_rules" {
   type = list(object({
     condition = optional(string)