From f3c6fb35ea4ebc6772ca3be2a55b5d8453751f52 Mon Sep 17 00:00:00 2001
From: Sergei Ugdyzhekov <sergei.ugdyzhekov@jetbrains.com>
Date: Sat, 18 Apr 2020 20:33:18 +0200
Subject: [PATCH] feat: Use user specified CIDR instead of calculated

---
 README.md    | 15 +++++++--------
 variables.tf | 12 +++---------
 2 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index b79e4c4..3886af8 100644
--- a/README.md
+++ b/README.md
@@ -3,23 +3,22 @@ Terraform module to create network subnet with custom route tablea
 
 Features:
 * Assign route table to forward traffic through NAT or IGW e.g.
-* Network calculation based on VPC CIDR
 
 ## Usage
 
-Private subnet:
-```
+A private subnet:
+```hcl
 module "subnet" {
   source      = "github.com/jetbrains-infra/terraform-aws-subnet"
-  project     = "FooBar" 
+  project     = "FooBar"
   vpc_id      = "${local.vpc_id}" 
-  name        = "DB" 
+  name        = "DB"
   route_table = "${aws_route_table.intenert_access.id}"
 }
 ```
 
 All options with default values:
-```
+```hcl
 module "subnet" {
   source       = "github.com/jetbrains-infra/terraform-aws-subnet"
   project      = "FooBar" // required
@@ -28,9 +27,9 @@ module "subnet" {
   zone         = "eu-west-1a"
   type         = "private"
   group        = "dbs"
-  shift        = 0 // How many subnets were already taken from VPC cidr block
-  network_mask = 8 // means 256 IP 
+  subnet_cidr  = "10.0.0.0/24"
   route_table  = "${aws_route_table.intenert_access.id}"
+}
 ```
 
 ## Outputs
diff --git a/variables.tf b/variables.tf
index 0407df5..084fd3d 100644
--- a/variables.tf
+++ b/variables.tf
@@ -18,13 +18,8 @@ variable "group" {
   description = "Group tag. You may specify it to define varous scopes for subnets of one type."
   default     = "common"
 }
-variable "shift" {
-  description = "How many subnets were already taken from VPC cidr block."
-  default     = 0
-}
-variable "network_mask" {
-  description = "Network mask in bites. 2 for /24 e.g. Default is 2 (256 IPs for subnet in VPC with /22 CIDR)."
-  default     = 2
+variable "subnet_cidr" {
+  description = "Subnet CIDR."
 }
 variable "route_table" {
   description = "Route table id."
@@ -38,8 +33,7 @@ locals {
   route_table = var.route_table
   vpc_id      = var.vpc_id
   vpc_cidr    = data.aws_vpc.default.cidr_block
-  newbites    = var.network_mask
-  subnet_cidr = cidrsubnet(local.vpc_cidr, local.newbites, var.shift) // var.shift because local.shift will not work
+  subnet_cidr = var.subnet_cidr
   purpose     = title(var.name)
   name        = "${local.purpose} ${var.type}"
   type        = lower(var.type)