A Deep Dive into Azure Service Endpoints and Private Endpoints

Azure networking offers Service Endpoints and Private Endpoints to securely connect Azure services to virtual networks (VNets). Both options improve security and connectivity, but they differ in implementation, use cases, and levels of isolation. This article provides a comprehensive understanding of these concepts by exploring the insights on both endpoints for clarity and flow..

Understanding Azure Service Endpoints: Secure Your VNet Connections

Service Endpoints extend your VNet identity to Azure services by routing traffic through the Azure backbone network. They allow secure access to Azure services without exposing traffic to the public internet.

Key Features:

• Traffic is routed through the Microsoft backbone network.

• Uses public IP addresses of Azure services but secures access at the subnet level.

• Relies on Network Security Groups (NSGs) for access control.

Use Cases:

• When you need a simple, cost-effective solution for securing connections.

• Suitable for scenarios where complete isolation from the public internet is not required.

• Commonly used with services like Azure Storage, SQL Database, and Key Vault.

Exploring Private Endpoints: Achieve Complete Isolation in Azure

Private Endpoints provide a private IP-based connection to Azure services within your VNet. They leverage Azure Private Link to completely isolate traffic from public networks.

Key Features:

• Assigns a private IP from your VNet to the Azure service.

• Requires private DNS zones for name resolution.

• Offers end-to-end isolation and enhanced security.

Use Cases:

• Ideal for workloads requiring strict isolation from the public internet.

• Suitable for overlapping address spaces.

• Necessary for sensitive workloads or compliance-driven environments (e.g., healthcare or finance).

• Works with services supporting Azure Private Link, such as Storage, SQL Database, App Services, and more.

Service Endpoints vs. Private Endpoints: Key Differences Explained

Choosing the Right Endpoint: Service or Private?

• Choose Service Endpoints if:

  • You need a simple setup without additional costs.

  • Your application does not require complete isolation from the public internet.

  • The service you are connecting to does not support Private Endpoints.

• Choose Private Endpoints if:

  • Your application requires strict isolation from public networks.

  • You are dealing with sensitive workloads or regulatory compliance needs.

  • The service supports Azure Private Link and you want enhanced security.

Implementing a Private Endpoint with Terraform: A Step-by-Step Guide

1. Create a Resource Group

    textresource "azurerm_resource_group" "demo_rg" {
      name     = "nimesh-demo-rg"
      location = "East US"
    }
   

2. Create a Virtual Network and Subnets

    textresource "azurerm_virtual_network" "demo_vnet" {
      name                = "demo-vnet"
      location            = azurerm_resource_group.demo_rg.location
      resource_group_name = azurerm_resource_group.demo_rg.name
      address_space       = ["10.0.0.0/16"]
    }
   
    resource "azurerm_subnet" "demo_vnet_subnet" {
      name                 = "demo-subnet"
      resource_group_name  = azurerm_resource_group.demo_rg.name
      virtual_network_name = azurerm_virtual_network.demo_vnet.name
      address_prefixes     = ["10.0.1.0/24"]
    }
   

3. Create a Storage Account

    textresource "azurerm_storage_account" "demo_sa" {
      name                     = "demostorageacct"
      resource_group_name      = azurerm_resource_group.demo_rg.name
      location                 = azurerm_resource_group.demo_rg.location
      account_tier             = "Standard"
      account_replication_type = "LRS"
    }
   

4. Set Up a Private Endpoint

    textresource "azurerm_private_endpoint" "demo_pvt_end" {
      name                = "demo-private-endpoint"
      location            = azurerm_resource_group.demo_rg.location
      resource_group_name = azurerm_resource_group.demo_rg.name
      subnet_id           = azurerm_subnet.demo_vnet_subnet.id
   
      private_service_connection {
        name                           = "demo_pvt_svc-connection"
        private_connection_resource_id = azurerm_storage_account.demo_sa.id
        subresource_names              = ["blob"]
        is_manual_connection           = false
      }
    }
   

5. Configure a Private DNS Zone

    textresource "azurerm_private_dns_zone" "pvt_dns_zone" {
      name                = "privatelink.blob.core.windows.net"
      resource_group_name = azurerm_resource_group.demo_rg.name
    }
   
    resource "azurerm_private_dns_zone_virtual_network_link" "demo_pvt_zone_vlink" {
      name                  = "dem-pvt-vnet-link"
      resource_group_name   = azurerm_resource_group.demo_rg.name
      private_dns_zone_name = azurerm_private_dns_zone.pvt_dns_zone.name
      virtual_network_id    = azurerm_virtual_network.demo_vnet.id
    }
   
    resource "azurerm_private_dns_a_record" "pvt_alias_record" {
      name                = "examplestorageacct"
      zone_name           = azurerm_private_dns_zone.pvt_dns_zone.name
      resource_group_name = azurerm_resource_group.demo_rg.name
      ttl                 = 300
      records             = [azurerm_private_endpoint.demo_pvt_end.private_ip_address]
    }
   

6. Apply the Terraform Plan

    bashterraform init
    terraform plan -out=tfplan
    terraform apply tfplan
   

Conclusion

In conclusion, understanding the differences between Azure Service Endpoints and Private Endpoints is crucial for optimizing the security and connectivity of your Azure services. Service Endpoints offer a straightforward, cost-effective solution for securing connections without complete isolation from the public internet, making them suitable for less sensitive applications. On the other hand, Private Endpoints provide enhanced security and complete isolation, ideal for sensitive workloads and compliance-driven environments. By carefully evaluating your specific needs and the supported services, you can choose the most appropriate endpoint solution to ensure robust and secure connectivity within your Azure infrastructure.