===== Terraform with PostgreSQL =====

==== Microsoft Azure and PostgreSQL Flexible Server ====

=== Useful Links ===
[https://learn.microsoft.com/en-us/azure/developer/terraform/get-started-windows-powershell]\\
[https://learn.microsoft.com/en-us/azure/developer/terraform/authenticate-to-azure-with-microsoft-account]\\
[https://learn.microsoft.com/en-us/azure/developer/terraform/deploy-postgresql-flexible-server-database?tabs=azure-cli]\\
[https://github.com/Azure/terraform/tree/master/quickstart/201-postgresql-fs-db]\\
[https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/postgresql_flexible_server]

The below commands will initialise Terraform, create an execution plan and apply it.\\
Afterwards you can clean up the resources created via the terraform destroy command.\\
<code>
terraform init -upgrade
terraform validate
terraform plan -out main.tfplan
terraform apply main.tfplan

terraform plan -destroy -out main.destroy.tfplan
terraform apply main.destroy.tfplan
</code>

=== Terraform Code ===
== providers.tf ==
<file yaml providers.tf>
terraform {
  required_version = ">=1.0"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "~>3.0"
    }
    random = {
      source  = "hashicorp/random"
      version = ">= 3.4.0"
    }
  }
}

provider "azurerm" {
  features {}
}
</file>

== variables.tf ==
<file yaml variables.tf>
variable "resource_group" {
  default     = "DoobDude-WebServer_group"
  description = "Default Resource Group."
}

variable "virtual_network" {
  default     = "DoobDude-WebServer-vnet"
  description = "Default Virtual Network."
}

variable "nsg" {
  default     = "DoobDude-WebServer-nsg"
  description = "Default Network Security Group."
}

variable "location" {
  default     = "UK South"
  description = "Location of the resource."
}
</file>

== main.tf ==
Uses existing resource group, virtual network and network security group

<file yaml main.tf>
resource "random_password" "pass" {
  length = 20
}

resource "azurerm_postgresql_flexible_server" "default" {
  name                   	      = "doob-tf-pg"
  resource_group_name    	      = var.resource_group
  location               	      = var.location
  version                	      = "16"
  public_network_access_enabled       = true
  administrator_login    	      = "adminTerraform"
  administrator_password 	      = random_password.pass.result
  zone                   	      = "1"
  storage_mb             	      = 32768
  storage_tier           	      = "P4"
  sku_name               	      = "B_Standard_B1ms"
  backup_retention_days  	      = 7
}
</file>

== postgresql-fs-db.tf ==
<file yaml postgresql-fs-db.tf>
locals {
  pg_config = {
    "log_lock_waits"              : "on",
    "log_min_duration_statement"  : "500"
    "log_statement"               : "ddl",
    "default_statistics_target"   : "250",
    "effective_io_concurrency"    : "50"
  }
}

resource "azurerm_postgresql_flexible_server_database" "default" {
  name      = "doobtf"
  collation = "en_US.utf8"
  charset   = "UTF8"
  server_id = azurerm_postgresql_flexible_server.default.id
}

resource "azurerm_postgresql_flexible_server_configuration" "default" {
  for_each = local.pg_config
  name  = each.key
  value = each.value
  server_id = azurerm_postgresql_flexible_server.default.id
}
</file>

== outputs.tf ==
<file yaml outputs.tf>
output "azurerm_postgresql_flexible_server" {
  value = azurerm_postgresql_flexible_server.default.name
}

output "postgresql_flexible_server_database_name" {
  value = azurerm_postgresql_flexible_server_database.default.name
}

output "postgresql_flexible_server_admin_password" {
  sensitive = true
  value     = azurerm_postgresql_flexible_server.default.administrator_password
}
</file>