Introduction
Terraform is Open Source Infrastructure as code which allow to Automate and Manage Infrastructure, Services and platform.
It is declarative language.
# Create the resource group
resource "azurerm_resource_group" "rg" {
name = "myResourceGroup-${random_integer.ri.result}"
location = "eastus"
}Where to Use Terraform:
Use Cases:
Create Infrastructure
Update Infrastructure
Replicate the Infrastructure
Architecture
Terraform Configurations Files
dev.tfvars,preprod.tfvars,prod.tfvars
Lets assume we are going to create Azure Web App service.
Provider configuration file consist of
Cloud Provider Declaration like Azure, AWS, Google Cloud
backend Remote state file configuration
terraform {
required_version = ">=0.12"
required_providers {
azurerm = {
source = "hashicorp/azurerm"
version = "~>2.0"
}
}
backend "azurerm" {
resource_group_name = "<storage_account_resource_group>"
storage_account_name = "<storage_account_name>"
container_name = "tfstate"
key = "codelab.microsoft.tfstate"
}
}
provider "azurerm" {
features {}
}It contains the main configuration module of infrastructure.
# Create the resource group
resource "azurerm_resource_group" "rg" {
name = var.resource_group_name
location = var.resource_group_location
}
# Create the Linux App Service Plan
resource "azurerm_app_service_plan" "appserviceplan" {
name = var.app_service_plan_name
location = azurerm_resource_group.rg.location
resource_group_name = azurerm_resource_group.rg.name
sku {
tier = "Free"
size = "F1"
}
}
# Create the web app, pass in the App Service Plan ID
resource "azurerm_app_service" "webapp" {
name = var.webapp_service_name
location = azurerm_resource_group.rg.location
resource_group_name = azurerm_resource_group.rg.name
app_service_plan_id = azurerm_app_service_plan.appserviceplan.id
}This helps to declare all the required variables used in main.tf file.
variable "resource_group_name" {
default = "webapp-rg"
description = "Name of the resource group."
}
variable "resource_group_location" {
default = "eastus"
description = "Location of the resource group."
}
variable "app_service_plan_name" {
default = "webapp-asp"
description = "Location of the resource group."
}
variable "webapp_service_name" {
default = "webapp-demo"
description = "Location of the resource group."
}This helps to extract the Resource detail and display.
output "resource_group_name" {
value = azurerm_resource_group.rg.name
}
output "webapp_service_name" {
value = azurerm_app_service.webapp.name
}
dev.tfvars
This is used for the defining the variables specific to the environment or service.
resource_group_name ="devops_dev_rg"
resource_group_location="eastus"
app_service_plan_name="asp-webapp"
webapp_service_name="devops-demo-dev"preprod.tfvars
resource_group_name ="devops_dev_rg"
resource_group_location="eastus"
app_service_plan_name="asp-webapp-prd"
webapp_service_name="devops-demo-dev"prod.tfvars
resource_group_name ="devops_dev_rg"
resource_group_location="eastus"
app_service_plan_name="name"
webapp_service_name="devops-demo-dev"Manage Backends
Backend helps to setup the terraform state file. As per best practice we will learn to setup the remote backend using Azure Storage Account.
1. Create Storage Account
2. Create Container and update the providers.tf
backend "azurerm" {
resource_group_name = "<storage_account_resource_group>"
storage_account_name = "<storage_account_name>"
container_name = "tfstate"
key = "terraform.tfstate"
}Workspaces
Workspace helps to manager multiple environment. Like dev,uat,prod.
Assume we are having three different infra setup under the same configuration file.
So for that we can create three workspace and run the terraform command. In Backend it will create three different state file instance per workspace.
Terraform Important Commands
terraform init
terraform refresh
terraform validate
terraform plan
terraform apply
terraform destroy --> Destroy Previously created Infrastructure
Terraform Execution flow
Setup Remote Backend
Create Azure Storage Account & Container which will be used as backend to store the terraform state file.
Update Provider.tf File
Once the Storage Create update the providers.tf with Details Like
terraform {
required_version = ">=0.12"
required_providers {
azurerm = {
source = "hashicorp/azurerm"
version = "~>2.0"
}
}
backend "azurerm" {
resource_group_name = "devops-terraform-iac"
storage_account_name = "iacterrafromstate"
container_name = "tfstate"
key = "terraform.tfstate"
}
}
provider "azurerm" {
features {}
}Setup Workflow File
For Demo we have created the Source Repo to create the azure web app.
Project is available at:
Workflow File:
Workflow YAML to Run the Terraform Project file.
Input Parameters
ENVIRONMENT --> Select Environment to deploy the Terraform Project
CreateWorkspace --> Yes if for First time run the Create workspace for Dev/Uat/Prod
on:
workflow_dispatch:
inputs:
#Name of your Environment
ENVIRONMENT:
description: 'Deployment Environment (Non-Prod/Pre-Prod/Prod)'
required: true
default: 'Non-Prod'
CreateWorkspace:
description: 'First Time Run -->Choose Yes'
required: true
default: 'no'Service Principal Secret for Deploy Infrastructure as Code
This can be also manage through KeyVault.
TF_ARM_CLIENT_ID
TF_ARM_CLIENT_SECRET
TF_ARM_SUBSCRIPTION_ID
TF_ARM_TENANT_ID
How to Run the Workflow
Once the setup is completed now we can run the workflow and see the result.
Create Workspace
Since we are assuming we have three environment we are going to create below workspace.
dev
uat
prod
This can be updated as per your requirement as well.
Run below Workflow:
On Successful Execution.
Result in Remote Backend Storage Account.
Run the Infrastructure Deployment
Result
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