Azure Flexible Server for MySQL and PostgreSQL

 hclresource "azurerm_resource_group" "foo" {
  name     = "foo"
  location = "eastus"
}

resource "azurerm_virtual_network" "bar" {
  name                = "bar-vn"
  location            = azurerm_resource_group.foo.location
  resource_group_name = azurerm_resource_group.foo.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_subnet" "baz" {
  name                 = "baz-sn"
  resource_group_name  = azurerm_resource_group.foo.name
  virtual_network_name = azurerm_virtual_network.bar.name
  address_prefixes     = ["10.0.2.0/24"]
  service_endpoints    = ["Microsoft.Storage"]

  delegation {
    name = "fs"

    service_delegation {
      name    = "Microsoft.DBforPostgreSQL/flexibleServers"
      actions = ["Microsoft.Network/virtualNetworks/subnets/join/action"]
    }
  }
}

resource "azurerm_private_dns_zone" "biz" {
  name                = "biz.postgres.database.azure.com"
  resource_group_name = azurerm_resource_group.foo.name
}

resource "azurerm_private_dns_zone_virtual_network_link" "foo" {
  name                  = "foo-postgresql"
  private_dns_zone_name = azurerm_private_dns_zone.biz.name
  virtual_network_id    = azurerm_virtual_network.bar.id
  resource_group_name   = azurerm_resource_group.foo.name
  depends_on            = [azurerm_subnet.baz]
}

module "postgresql_flexible_server" {
  source  = "solutions.corewide.com/azure/tf-azure-database-flexible-server/azurerm"
  version = "~> 3.2"

  name                = "bar"
  resource_group      = azurerm_resource_group.foo
  database_engine     = "postgresql"
  replica_count       = 2
  storage_size        = 128
  delegated_subnet_id = azurerm_subnet.baz.id

  private_dns_zone = {
    id                  = "/subscriptions/123-qwerty-456-uiop/resourceGroups/rg-data/providers/Microsoft.Network/privateDnsZones/bar.dbz.postgres.database.azure.com"
    name                = "biz.dbz.postgres.database.azure.com"
    resource_group_name = azurerm_resource_group.foo.name
  }

  databases = [
    {
      name      = "app"
      charset   = "utf8"
      collation = "en_US.utf8"
    },
  ]

  configuration = {
    "backslash_quote"  = "on"
    "azure.extensions" = "CUBE,CITEXT,BTREE_GIST"
  }

  firewall_rules = [
    {
      target = "all"
      name   = "developer"
      cidr   = "xxx.xxx.xxx.xxx/32"
    },
    {
      target           = "replica"
      name             = "backend"
      start_ip_address = "xxx.xxx.xxx.xxx"
      end_ip_address   = "yyy.yyy.yyy.yyy"
    },
  ]
}