Email alert notification receipts

Rakefile

@@ -1,6 +1,7 @@
 require 'fileutils'
 require 'rspec/core/rake_task'
 require 'tmpdir'
+require 'aws-sdk-resources'
 
 PROJECT_DIR = 'projects'
 
@@ -110,7 +111,7 @@ end
 
 
 desc 'Apply the terraform resources'
-task apply: [:configure_state] do
+task apply: [:configure_state, :latest_version_id] do
   tmp_dir = _flatten_project
 
   puts "terraform apply -var-file=variables/#{deploy_env}.tfvars #{tmp_dir}"
@@ -121,6 +122,23 @@ task apply: [:configure_state] do
 end
 
 
+desc 'Latest Lambda version ID'
+task :latest_version_id do
+  lambda_filename = ENV['TF_VAR_LAMBDA_FILENAME']
+  target_file = "#{project_name}/#{lambda_filename}"
+  if lambda_filename
+    s3 = Aws::S3::Resource.new(region: 'eu-west-1')
+    bucket = s3.bucket("govuk-lambda-applications-#{deploy_env}")
+    begin
+      version_id = bucket.object(target_file).version_id
+    rescue Aws::S3::Errors::NotFound
+      abort "File not found: s3://govuk-lambda-applications-#{deploy_env}/#{target_file}"
+    end
+    ENV['TF_VAR_LAMBDA_VERSIONID'] = version_id
+  end
+end
+
+
 desc 'Destroy the terraform resources'
 task destroy: [:configure_state] do
   tmp_dir = _flatten_project
@@ -134,7 +152,7 @@ end
 
 
 desc 'Show the plan'
-task plan: [:configure_state] do
+task plan: [:configure_state, :latest_version_id] do
   tmp_dir = _flatten_project
 
   system("terraform plan -module-depth=-1 -var-file=variables/#{deploy_env}.tfvars #{tmp_dir}")

projects/email_alert_notifications/README.md

@@ -0,0 +1,20 @@
+# Email Alert Notifications
+
+This project sets up an S3 bucket and a Lambda that parses files,
+extracts `data-govuk-request-id` and renames the file accordingly as
+either:
+
+    travel-advice-alerts/<data-govuk-request-id>.msg
+
+or if the file doesn't contain a `data-govuk-request-id`
+
+    no-request-id/<uuid>.msg
+
+## Manual Steps
+
+There is a manual step required for this 'app'.
+
+* An SES domain with a RuleSet containing an action that writes to the S3
+bucket (`govuk-email-alert-notifications`). An address on this domain will be
+subscribed to all of the travel advice country alerts
+

projects/email_alert_notifications/resources/email_alert_notifications.tf

@@ -0,0 +1,81 @@
+variable "s3_bucket_name" {
+  default = "govuk-email-alert-notifications"
+}
+
+variable "environment"{
+}
+
+variable "LAMBDA_FILENAME"{
+}
+
+variable "LAMBDA_VERSIONID"{
+}
+
+variable "lambda_bucket"{
+  default = "govuk-lambda-applications"
+}
+
+resource "template_file" "s3_bucket_policy" {
+  template = "${file("projects/email_alert_notifications/templates/email_alert_s3_bucket_policy.json")}"
+  vars {
+    account_id = "${element(split(":", aws_iam_role.lambda_execute_and_write_to_email_alert_bucket.arn), 4)}"
+    bucket_name = "${var.s3_bucket_name}-${var.environment}"
+    lambda_role = "${aws_iam_role.lambda_execute_and_write_to_email_alert_bucket.arn}"
+  }
+}
+
+resource "template_file" "put_and_delete_to_email_alert_bucket_policy" {
+  template = "${file("projects/email_alert_notifications/templates/put_and_delete_to_s3_policy.json")}"
+  vars {
+    resource_arn = "${aws_s3_bucket.email_alert_inbox_bucket.arn}"
+  }
+}
+
+resource "aws_s3_bucket" "email_alert_inbox_bucket" {
+  bucket = "${var.s3_bucket_name}-${var.environment}"
+  acl = "public-read"
+  policy = "${template_file.s3_bucket_policy.rendered}"
+}
+
+resource "aws_iam_role" "lambda_execute_and_write_to_email_alert_bucket" {
+  name = "lambda_execute_and_write_to_email_alert_bucket"
+  assume_role_policy = "${file("projects/email_alert_notifications/templates/lambda_assume_role_policy.json")}"
+}
+
+resource "aws_iam_role_policy" "put_and_delete_to_email_alert_bucket" {
+  name = "put_and_delete_to_email_alert_bucket"
+  role = "${aws_iam_role.lambda_execute_and_write_to_email_alert_bucket.id}"
+  policy = "${template_file.put_and_delete_to_email_alert_bucket_policy.rendered}"
+}
+
+resource "aws_iam_role_policy" "write_to_logs" {
+  name = "write_to_logs"
+  role = "${aws_iam_role.lambda_execute_and_write_to_email_alert_bucket.id}"
+  policy = "${file("projects/email_alert_notifications/templates/write_to_logs_policy.json")}"
+}
+
+resource "aws_lambda_function" "rename_email_files_with_request_id"{
+  s3_bucket = "${var.lambda_bucket}-${var.environment}"
+  s3_key="${var.LAMBDA_FILENAME}"
+  s3_object_version="${var.LAMBDA_VERSIONID}"
+  function_name = "rename_email_files_with_request_id"
+  role = "${aws_iam_role.lambda_execute_and_write_to_email_alert_bucket.arn}"
+  handler = "rename_email_files_with_request_id.lambda_handler"
+  runtime = "python2.7"
+}
+
+resource "aws_lambda_permission" "allow_email_alert_inbox_bucket" {
+    statement_id = "AllowExecutionFromS3Bucket"
+    action = "lambda:InvokeFunction"
+    function_name = "${aws_lambda_function.rename_email_files_with_request_id.arn}"
+    principal = "s3.amazonaws.com"
+    source_arn = "${aws_s3_bucket.email_alert_inbox_bucket.arn}"
+}
+
+resource "aws_s3_bucket_notification" "email_alert_inbox_bucket_notification" {
+    bucket = "${aws_s3_bucket.email_alert_inbox_bucket.id}"
+    lambda_function {
+      lambda_function_arn = "${aws_lambda_function.rename_email_files_with_request_id.arn}"
+      events = ["s3:ObjectCreated:Put"]
+    }
+}

projects/email_alert_notifications/templates/email_alert_s3_bucket_policy.json

@@ -0,0 +1,32 @@
+{
+  "Version": "2012-10-17",
+  "Id": "${uuid()}",
+  "Statement": [
+    {
+      "Effect": "Allow",
+      "Principal": {
+        "AWS": "${lambda_role}"
+      },
+      "Action": [
+        "s3:PutObject",
+        "s3:DeleteObject",
+        "s3:GetObject"
+      ],
+      "Resource": "arn:aws:s3:::${bucket_name}/*"
+    },
+    {
+      "Sid": "GiveSESPermissionToWriteEmail",
+      "Effect": "Allow",
+      "Principal": {
+        "Service": "ses.amazonaws.com"
+      },
+      "Action": "s3:PutObject",
+      "Resource": "arn:aws:s3:::${bucket_name}/*",
+      "Condition": {
+        "StringEquals": {
+          "aws:Referer": "${account_id}"
+        }
+      }
+    }
+  ]
+}

projects/email_alert_notifications/templates/lambda_assume_role_policy.json

@@ -0,0 +1,13 @@
+{
+  "Version": "2012-10-17",
+  "Statement": [
+    {
+      "Action": "sts:AssumeRole",
+      "Principal": {
+        "Service": "lambda.amazonaws.com"
+      },
+      "Effect": "Allow",
+      "Sid": ""
+    }
+  ]
+}

projects/email_alert_notifications/templates/put_and_delete_to_s3_policy.json

@@ -0,0 +1,15 @@
+{
+  "Version": "2012-10-17",
+  "Statement": [
+    {
+      "Action": [
+        "s3:getObject",
+        "s3:putObject",
+        "s3:deleteObject",
+        "s3:putObjectAcl"
+      ],
+      "Effect": "Allow",
+      "Resource": "${resource_arn}"
+    }
+  ]
+}

projects/email_alert_notifications/templates/write_to_logs_policy.json

@@ -0,0 +1,14 @@
+{
+  "Version": "2012-10-17",
+  "Statement": [
+    {
+      "Effect": "Allow",
+      "Action": [
+        "logs:CreateLogGroup",
+        "logs:CreateLogStream",
+        "logs:PutLogEvents"
+      ],
+      "Resource": "arn:aws:logs:*:*:*"
+    }
+  ]
+}