Support budget by tag

Author: Steven Nemetz

README.md

@@ -2,7 +2,9 @@
 
 Terraform module to setup AWS budgets and notifications
 
-This is fairly specific for now. It can create budgets for multiple linked accounts. Each with it's own limit.
+For now it can manage 2 types of budgets:
+ - Account budgets for a single account or multiple linked accounts. Each with it's own limit.
+ - Budget by tag
 Notification is only supported for a single email address
 
 NOTE: Setting up notification and subscribers is not currently supported in Terraform

examples/cost-tag-monthly/README.md

@@ -0,0 +1 @@
+# Example: Monthly budget by tag

examples/cost-tag-monthly/main.tf

@@ -0,0 +1,7 @@
+module "budget-1" {
+  source             = "../../"
+  emails             = ["user@company.com", "user2@company.com"]
+  budget_name        = "service-1"
+  budget_name_prefix = "Testing-"
+  tag_value          = "service-1"
+}

examples/cost-tag-monthly/providers.tf

@@ -0,0 +1,10 @@
+provider "aws" {
+  region = "${var.region}"
+
+  # Make it faster by skipping something
+  skip_get_ec2_platforms      = true
+  skip_metadata_api_check     = true
+  skip_region_validation      = true
+  skip_credentials_validation = true
+  skip_requesting_account_id  = true
+}

examples/cost-tag-monthly/variables.tf

@@ -0,0 +1,3 @@
+variable "region" {
+  default = "us-west-2"
+}

examples/cost-tag-quarterly/README.md

@@ -0,0 +1 @@
+# Example: Quarterly budget by tag

examples/cost-tag-quarterly/main.tf

@@ -0,0 +1,8 @@
+module "budget-1" {
+  source             = "../../"
+  emails             = ["user@company.com", "user2@company.com"]
+  budget_name        = "service-1"
+  budget_name_prefix = "Testing-"
+  tag_value          = "service-1"
+  time_unit          = "QUARTERLY"
+}

examples/cost-tag-quarterly/providers.tf

@@ -0,0 +1,10 @@
+provider "aws" {
+  region = "${var.region}"
+
+  # Make it faster by skipping something
+  skip_get_ec2_platforms      = true
+  skip_metadata_api_check     = true
+  skip_region_validation      = true
+  skip_credentials_validation = true
+  skip_requesting_account_id  = true
+}

examples/cost-tag-quarterly/variables.tf

@@ -0,0 +1,3 @@
+variable "region" {
+  default = "us-west-2"
+}

main.tf

@@ -5,34 +5,70 @@ data "aws_caller_identity" "current" {}
 
 # https://docs.aws.amazon.com/aws-cost-management/latest/APIReference/API_budgets_CostTypes.html
 #
-/*
+/**/
 # This is future work for single budget that can set most things
 locals {
   cost_filters = {
     AZ = {
       AZ = ""
     }
+
     LinkedAccount = {
-      LinkedAccount = "${join(",", var.account_ids)}"
+      #LinkedAccount = "${join(",", var.account_ids)}"
     }
+
     Operation = {
       Operation = ""
     }
+
     PurchaseType = {
       PurchaseType = ""
     }
+
     Service = {
       Service = ""
     }
+
     TagKeyValue = {
-      TagKeyValue = "Stack$$${var.service}"
+      TagKeyValue = "user:${var.tag_key}$$${var.tag_value}"
     }
+
     UsageType = {
       UsageType = ""
     }
   }
 }
+
 /**/
+resource "aws_budgets_budget" "budget" {
+  count        = "${length(var.budgets) == 0 ? 1 : 0}"
+  account_id   = "${data.aws_caller_identity.current.account_id}"
+  name         = "${var.budget_name_prefix}${var.budget_name}-${title(lower(var.time_unit))}"
+  budget_type  = "${var.budget_type}"
+  limit_unit   = "${var.limit_unit}"
+  time_unit    = "${var.time_unit}"
+  cost_filters = "${local.cost_filters[var.cost_filter_type]}"
+
+  limit_amount = "${var.time_unit == "ANNUALLY" ?
+    var.limit_amount * 12 :
+    var.time_unit == "QUARTERLY" ?
+      var.limit_amount * 3 :
+      var.limit_amount
+  }"
+
+  time_period_start = "${var.time_unit == "ANNUALLY" ?
+    "${substr(timestamp(), 0, 5)}01-01_00:00" :
+    var.time_unit == "QUARTERLY" ?
+      "${substr(timestamp(), 0, 5)}${format("%02d", (substr(timestamp(), 5, 2) - 1) / 3 * 3 + 1)}-01_00:00" :
+      "${substr(timestamp(), 0, 8)}01_00:00"
+  }"
+
+  lifecycle {
+    ignore_changes = ["time_period_start"]
+  }
+}
+
+# Multiple linked account budgets
 resource "aws_budgets_budget" "budgets" {
   count       = "${length(var.budgets)}"
   account_id  = "${data.aws_caller_identity.current.account_id}"