Visualizing your cloud resources with dot and Terraform

Terraform is able to generate graph files in dot (graph description language) format from your deployment plan. With some tooling the dot files be generated into image files. This makes reviewing and talking about Terraform templates easier. You are able to review a visual graph before deployment.

Here is a get started guide for Terraform on Azure.

GrapViz, dot processing tool

A tool to interpret dot files is GrapViz. It takes a dot file and generates an image.

Create the visualization of your resources

I have created a terraform example with 3 VMs in separate subnets:

# Configure the Azure Resource Manager Provider
provider "azurerm" {
  subscription_id = "..."
  client_id       = "..."
  client_secret   = "..."
  tenant_id       = "..."
}

variable "location" { default = "West Europe" }
variable "username" { default = "adminuser" }
variable "password" { default = "Pass654321" }

resource "azurerm_resource_group" "test" {
  name     = "HelloWorld"
  location = "${var.location}"
}

resource "azurerm_virtual_network" "test" {
  name                = "test"
  address_space       = ["10.0.0.0/16"]
  location            = "${var.location}"
  resource_group_name = "${azurerm_resource_group.test.name}"
}

resource "azurerm_subnet" "test" {
  name                 = "test"
  resource_group_name  = "${azurerm_resource_group.test.name}"
  virtual_network_name = "${azurerm_virtual_network.test.name}"
  address_prefix       = "10.0.2.0/24"
}

resource "azurerm_subnet" "test2" {
  name                 = "test2"
  resource_group_name  = "${azurerm_resource_group.test.name}"
  virtual_network_name = "${azurerm_virtual_network.test.name}"
  address_prefix       = "10.0.3.0/24"
}

resource "azurerm_subnet" "test3" {
  name                 = "test3"
  resource_group_name  = "${azurerm_resource_group.test.name}"
  virtual_network_name = "${azurerm_virtual_network.test.name}"
  address_prefix       = "10.0.4.0/24"
}

resource "azurerm_network_interface" "test" {
  name                = "test"
  location            = "${var.location}"
  resource_group_name = "${azurerm_resource_group.test.name}"
  ip_configuration {
    name                          = "testconfiguration1"
    subnet_id                     = "${azurerm_subnet.test.id}"
    private_ip_address_allocation = "dynamic"
  }
}

resource "azurerm_network_interface" "test2" {
  name                = "test2"
  location            = "${var.location}"
  resource_group_name = "${azurerm_resource_group.test.name}"
  ip_configuration {
    name                          = "testconfiguration2"
    subnet_id                     = "${azurerm_subnet.test2.id}"
    private_ip_address_allocation = "dynamic"
  }
}

resource "azurerm_network_interface" "test3" {
  name                = "test3"
  location            = "${var.location}"
  resource_group_name = "${azurerm_resource_group.test.name}"
  ip_configuration {
    name                          = "testconfiguration3"
    subnet_id                     = "${azurerm_subnet.test3.id}"
    private_ip_address_allocation = "dynamic"
  }
}

resource "azurerm_storage_account" "test" {
  name                = "helloworld25662"
  resource_group_name = "${azurerm_resource_group.test.name}"
  location            = "${var.location}"
  account_type        = "Standard_LRS"
}

resource "azurerm_storage_container" "test" {
  name                  = "helloworld"
  resource_group_name   = "${azurerm_resource_group.test.name}"
  storage_account_name  = "${azurerm_storage_account.test.name}"
  container_access_type = "private"
}

resource "azurerm_virtual_machine" "test" {
  name                  = "helloworld"
  location              = "${var.location}"
  resource_group_name   = "${azurerm_resource_group.test.name}"
  network_interface_ids = ["${azurerm_network_interface.test.id}"]
  vm_size               = "Standard_A0"

  storage_image_reference {
    publisher = "MicrosoftWindowsServer"
    offer     = "WindowsServer"
    sku       = "2016-Nano-Server-Technical-Preview"
    version   = "latest"
  }

  storage_os_disk {
    name          = "myosdisk1"
    vhd_uri       = "${azurerm_storage_account.test.primary_blob_endpoint}${azurerm_storage_container.test.name}/myosdisk1.vhd"
    caching       = "ReadWrite"
    create_option = "FromImage"
  }

  os_profile {
    computer_name  = "helloworld"
    admin_username = "${var.username}"
    admin_password = "${var.password}"
  }
}

resource "azurerm_virtual_machine" "test2" {
  name                  = "helloworld2"
  location              = "${var.location}"
  resource_group_name   = "${azurerm_resource_group.test.name}"
  network_interface_ids = ["${azurerm_network_interface.test2.id}"]
  vm_size               = "Standard_A0"

  storage_image_reference {
    publisher = "MicrosoftWindowsServer"
    offer     = "WindowsServer"
    sku       = "2016-Nano-Server-Technical-Preview"
    version   = "latest"
  }

  storage_os_disk {
    name          = "myosdisk2"
    vhd_uri       = "${azurerm_storage_account.test.primary_blob_endpoint}${azurerm_storage_container.test.name}/myosdisk2.vhd"
    caching       = "ReadWrite"
    create_option = "FromImage"
  }

  os_profile {
    computer_name  = "helloworld2"
    admin_username = "${var.username}"
    admin_password = "${var.password}"
  }
}

resource "azurerm_virtual_machine" "test3" {
  name                  = "helloworld3"
  location              = "${var.location}"
  resource_group_name   = "${azurerm_resource_group.test.name}"
  network_interface_ids = ["${azurerm_network_interface.test3.id}"]
  vm_size               = "Standard_A1"

  storage_image_reference {
    publisher = "MicrosoftWindowsServer"
    offer     = "WindowsServer"
    sku       = "2016-Nano-Server-Technical-Preview"
    version   = "latest"
  }

  storage_os_disk {
    name          = "myosdisk3"
    vhd_uri       = "${azurerm_storage_account.test.primary_blob_endpoint}${azurerm_storage_container.test.name}/myosdisk3.vhd"
    caching       = "ReadWrite"
    create_option = "FromImage"
  }

  os_profile {
    computer_name  = "helloworld3"
    admin_username = "${var.username}"
    admin_password = "${var.password}"
  }
}

This will create your resource graph:

resource graph
Azure resource graph
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