tfvarsauto

Just utility that creates variables definition and outputs definition from terraform code

Installation

You need to have rust to build binary first. And run in the root folder of this repository

$ cargo build --release
$ cp target/release/tfvarsauto ${HOME}/bin/

How to install Rust you can read in official Rust documentation ;)

Usage

$ ./tfvarsauto -h
Usage: tfvarsauto [-h] [-m main.tf] [-v vars.tf] [-o outputs.tf]

Creates variables definition and
outputs definition from terraform code

Options:
    -h, --help          Print the usage menu
    -m, --main main.tf  The name of file for input with main terraform code,
                        main.tf by default
    -v, --vars vars.tf  The name of file to output with variables definition,
                        vars.tf by default
    -o, --outputs outputs.tf
                        The name of file to output with outputs definition,
                        outputs.tf by default

Example

Let's imagine, that you wrote some terraform module, and save it in file main.tf, like this:

main.tf

//noinspection MissingProperty
provider "azurerm" {
  version         = "~> 1.44"
  subscription_id = data.vault_generic_secret.az_subscription_id.data["id"]
  tenant_id       = data.vault_generic_secret.az_tenant_id.data["id"]
  client_id       = data.vault_generic_secret.az_client_id.data["id"]
  client_secret   = data.vault_generic_secret.az_client_secret.data["id"]
}

terraform {
  backend "azurerm" {
    storage_account_name = "tfstorageaccount"
    container_name       = "tfstate"
    key                  = "project.terraform.tfstate"
  }
}

provider "random" {
  version = "~> 2.1"
}

data "vault_generic_secret" "az_subscription_id" {
  path = var.az_subscription_id
}

data "vault_generic_secret" "az_tenant_id" {
  path = var.az_tenant_id
}

data "vault_generic_secret" "az_client_id" {
  path = var.az_client_id
}

data "vault_generic_secret" "az_client_secret" {
  path = var.az_client_secret
}

data "vault_generic_secret" "ssh_public" {
  path = var.ssh_public
}

locals {
  common_tags = {
    "Environment"    = upper(var.env_type)
  }
}

module "rsg" {
  source                 = "../modules/global/resource_group"
  az_location            = var.az_location
  az_resource_group_name = lower("RG-${local.common_tags["Environment"]}")

  tags = local.common_tags
}


module "vnet" {
  source                 = "../modules/network/vnet"
  az_location            = module.rsg.az_resource_group_location
  az_resource_group_name = module.rsg.az_resource_group_name
  az_vnet_name           = "proj-${local.common_tags["Environment"]}"
  az_vnet_cidr           = var.az_vnet_cidr

  tags = local.common_tags
}

module "subnet" {
  source                 = "../modules/network/subnet"
  az_resource_group_name = module.rsg.az_resource_group_name
  az_subnet_name         = "proj-${local.common_tags["Environment"]}"
  az_subnets             = var.az_subnets
  az_vnet_name           = module.vnet.az_vnet_name
  az_vnet_cidr           = module.vnet.az_vnet_address_space
  service_endpoints      = var.az_svc_endpoints
  az_subnet_bits         = var.az_subnet_bits
}

resource "azurerm_firewall_network_rule_collection" "az_firewall_rules" {
  action              = "Allow"
  azure_firewall_name = var.az_firewall_name
  name                = "test-name"
  priority            = 100
  resource_group_name = module.rsg.az_resource_group_name
  rule {
    name                  = "test-TCP"
    source_addresses      = [element(module.subnet.az_subnet_cidr, 1)]
    destination_addresses = var.az_firewall_tcp.dest_addrs
    destination_ports     = var.az_firewall_tcp.dest_ports
    protocols             = ["TCP"]
  }
  rule {
    name                  = "test-UDP"
    source_addresses      = [element(module.subnet.az_subnet_cidr, 1)]
    destination_addresses = var.az_firewall_udp.dest_addrs
    destination_ports     = var.az_firewall_udp.dest_ports
    protocols             = ["UDP"]
  }
}

resource "azurerm_route_table" "az_route_default" {
  location            = module.rsg.az_resource_group_location
  resource_group_name = module.rsg.az_resource_group_name
  name                = "route_table"

  route {
    name                   = "default"
    address_prefix         = "0.0.0.0/0"
    next_hop_type          = "VirtualAppliance"
    next_hop_in_ip_address = var.private_ip_address
  }
  route {
    name           = "fw"
    address_prefix = "${var.ip_address}/32"
    next_hop_type  = "Internet"
  }

  tags = local.common_tags
}

resource "azurerm_subnet_route_table_association" "az_assign_route" {
  subnet_id      = element(module.subnet.az_subnet_id, 1)
  route_table_id = azurerm_route_table.az_route_default.id
}

Now you have to create vars.tf with all variables definition and outputs.tf with all outputs of the module. So, you can make it with the tfvarauto utility. Just run it and you will have:

vars.tf

variable "az_client_id" {
  type = string
  default = null
  description = ""
}

variable "az_client_secret" {
  type = string
  default = null
  description = ""
}

variable "az_firewall_name" {
  type = string
  default = null
  description = ""
}

variable "az_location" {
  type = string
  default = null
  description = ""
}

variable "az_subnet_bits" {
  type = string
  default = null
  description = ""
}

variable "az_subnets" {
  type = string
  default = null
  description = ""
}

variable "az_subscription_id" {
  type = string
  default = null
  description = ""
}

variable "az_svc_endpoints" {
  type = string
  default = null
  description = ""
}

variable "az_tenant_id" {
  type = string
  default = null
  description = ""
}

variable "az_vnet_cidr" {
  type = string
  default = null
  description = ""
}

variable "env_type" {
  type = string
  default = null
  description = ""
}

variable "ssh_public" {
  type = string
  default = null
  description = ""
}

So, you won't forget to define any variable and all what you need is change types, default values and add description!

outputs.tf

output "data_vault_generic_secret_az_client_id" {
  value = data.vault_generic_secret.az_client_id
  description = ""
}

output "data_vault_generic_secret_az_client_secret" {
  value = data.vault_generic_secret.az_client_secret
  description = ""
}

output "data_vault_generic_secret_az_subscription_id" {
  value = data.vault_generic_secret.az_subscription_id
  description = ""
}

output "data_vault_generic_secret_az_tenant_id" {
  value = data.vault_generic_secret.az_tenant_id
  description = ""
}

output "data_vault_generic_secret_ssh_public" {
  value = data.vault_generic_secret.ssh_public
  description = ""
}

output "locals_common_tags" {
  value = locals.common_tags
  description = ""
}

output "module_rsg" {
  value = module.rsg
  description = ""
}

output "module_subnet" {
  value = module.subnet
  description = ""
}

output "module_vnet" {
  value = module.vnet
  description = ""
}

output "resource_azurerm_firewall_network_rule_collection_az_firewall_rules" {
  value = azurerm_firewall_network_rule_collection.az_firewall_rules
  description = ""
}

output "resource_azurerm_route_table_az_route_default" {
  value = azurerm_route_table.az_route_default
  description = ""
}

output "resource_azurerm_subnet_route_table_association_az_assign_route" {
  value = azurerm_subnet_route_table_association.az_assign_route
  description = ""
}

The same situation - you can copy blocks to define corresponded outputs from resources and add values. But you already have the template.