Basic auth

README.md

@@ -38,6 +38,7 @@ The [`master`](https://github.com/codequest-eu/terraform-single-page-app/tree/ma
 
 | Name                            | Description                                                                                                                                 |  Type  |      Default       | Required |
 | ------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- | :----: | :----------------: | :------: |
+| basic\_auth\_credentials        | Basic auth credentials in user:pass format                                                                                                  | string |        n/a         |   yes    |
 | bucket                          | Kebab-cased bucket name override                                                                                                            | string |        `""`        |    no    |
 | certificate\_arn                | ACM certificate ARN to use instead of the default cloudfront certificate                                                                    | string |        `""`        |    no    |
 | cloudfront\_price\_class        | CloudFront price class, which specifies where the distribution should be replicated, one of: PriceClass_100, PriceClass_200, PriceClass_All | string | `"PriceClass_100"` |    no    |

example/main.tf

@@ -20,8 +20,9 @@ module "basic" {
   }
 
   # only project name and environment are required
-  project     = "terraform-spa"
-  environment = "example"
+  project                = "terraform-spa-auth"
+  environment            = "example"
+  basic_auth_credentials = "example:app"
 }
 
 resource "aws_s3_bucket_object" "basic_index" {

main.tf

@@ -1,3 +1,7 @@
+provider "aws" {
+  alias = "middleware"
+}
+
 resource "aws_s3_bucket" "assets" {
   bucket = "${var.bucket != "" ? var.bucket : "${local.name_prefix}-assets"}"
   acl    = "private"
@@ -94,6 +98,12 @@ resource "aws_cloudfront_distribution" "assets" {
         forward = "none"
       }
     }
+
+    lambda_function_association {
+      event_type   = "viewer-request"
+      lambda_arn   = "${module.basic_auth.arn}"
+      include_body = false
+    }
   }
 
   custom_error_response {
@@ -118,3 +128,34 @@ resource "aws_cloudfront_distribution" "assets" {
 
   tags = "${local.tags}"
 }
+
+module "middleware_common" {
+  source = "./middleware_common"
+
+  name_prefix = "${local.name_prefix}"
+
+  providers = {
+    aws = "aws.middleware"
+  }
+}
+
+data "template_file" "basic_auth" {
+  template = "${file("${path.module}/templates/basic-auth.js")}"
+
+  vars {
+    credentials = "${base64encode("${var.basic_auth_credentials}")}"
+  }
+}
+
+module "basic_auth" {
+  source = "./middleware"
+
+  name     = "${local.name_prefix}-basic-auth"
+  code     = "${data.template_file.basic_auth.rendered}"
+  role_arn = "${module.middleware_common.role_arn}"
+  tags     = "${local.tags}"
+
+  providers = {
+    aws = "aws.middleware"
+  }
+}

templates/basic-auth.js

@@ -0,0 +1,26 @@
+// Expected Authorization header value
+const authorization = "Basic ${credentials}"
+
+exports.handler = (event, context, callback) => {
+  // Get request and request headers
+  const request = event.Records[0].cf.request
+  const headers = request.headers
+
+  // Require Basic authentication
+  if (
+    !headers.authorization ||
+    headers.authorization[0].value !== authorization
+  ) {
+    return callback(null, {
+      status: "401",
+      statusDescription: "Unauthorized",
+      body: "Unauthorized",
+      headers: {
+        "www-authenticate": [{ key: "WWW-Authenticate", value: "Basic" }],
+      },
+    })
+  }
+
+  // Continue request processing if authentication passed
+  callback(null, request)
+}

variables.tf

@@ -46,3 +46,7 @@ variable "bucket" {
   description = "Kebab-cased bucket name override"
   default     = ""
 }
+
+variable "basic_auth_credentials" {
+  description = "Basic auth credentials in user:pass format"
+}