Tag: cloud

Enable OpenTelemetry in Azure Functions: The Easiest Way via Azure Portal

Good news! As of June 2025, OpenTelemetry is now in preview for Azure Functions. If you want basic observability without writing code or installing libraries, you can now enable distributed tracing directly from the Azure Portal.

This quick guide shows the simplest way to enable OpenTelemetry in Azure Functions using built-in features — no NuGet packages or custom code needed.

What You Need

  • An existing Azure Function App (v4)

  • Application Insights already enabled (most new Function Apps have this by default)

Continue reading “Enable OpenTelemetry in Azure Functions: The Easiest Way via Azure Portal”

Introducing Azure Private Subnets: Enhancing Security by Disabling Default Outbound Access

Azure Networking Tips & Techniques - Part 1

Azure recently announced the general availability of Private Subnet, a new feature that allows you to disable the implicit outbound Internet connectivity for virtual machines in a subnet. In this blog post, we’ll cover:

  1. What Azure Private Subnets are and why they matter

  2. Key benefits of disabling default outbound access

  3. Step-by-step instructions to configure a private subnet via the Azure Portal

  4. Verifying that default outbound has been disabled

What Is an Azure Private Subnet?

Traditionally, when you create a subnet in an Azure Virtual Network (VNet) without any explicit outbound connectivity (such as a NAT gateway, Public IP, or Load Balancer), Azure automatically provides a default outbound access IP for those VMs. While this is convenient, it introduces an implicit egress path—VMs can communicate with public endpoints without you having explicitly configured any egress resources.

A Private Subnet in Azure is simply a subnet where this default outbound access is turned off. Consequently:

  • Any VM deployed within that subnet cannot reach the Internet by default.

  • You must explicitly configure an alternative egress mechanism if VMs need outbound connectivity (e.g., NAT Gateway, Standard Load Balancer, Firewall, or a Public IP assigned directly to the NIC).

By removing the implicit outbound IP, Azure Private Subnets enforce a “zero trust” approach: no VM can communicate externally until you grant it an explicit, auditable path.

Why Disable Default Outbound Access?

  1. Secure by Default
    Default outbound IPs are not customer-owned and can change unpredictably. By disabling implicit egress, you ensure VMs only send traffic externally when you explicitly allow it, reducing your attack surface.

  2. Prevent Data Exfiltration
    In regulated or highly sensitive environments (for example, PCI-DSS or HIPAA workloads), any unsolicited outbound route can pose compliance or security risks. Private Subnets eliminate unexpected data exfiltration channels.

  3. Encourage Explicit Egress Configuration
    When default outbound is disabled, you must provision a known, managed egress mechanism (like a NAT Gateway), which can be tightly monitored for logging, analytics, and cost control. This “explicit-over-implicit” model aligns with best practices for cloud network security.

Continue reading “Introducing Azure Private Subnets: Enhancing Security by Disabling Default Outbound Access”

Azure Resource Locks – The One Feature You’re Probably Not Using (But Should Be)

Accidental deletion or modification of critical resources in Azure is more common than most teams would like to admit. And unlike on-prem environments, where layers of approvals or access barriers might slow someone down, Azure’s agility can sometimes be its own worst enemy — especially when production workloads are one click away from disappearing.

Enter: Azure Resource Locks — your environment’s seatbelt.

What Are Azure Resource Locks?

Azure Resource Locks are a built-in feature that allow you to restrict operations on resources, resource groups, or subscriptions. These locks act as a last line of defense — even if someone has Contributor or Owner permissions, a lock will block unwanted actions like deletion or configuration changes.

Continue reading “Azure Resource Locks – The One Feature You’re Probably Not Using (But Should Be)”

How to Use Azure Policy for Better Cloud Management

When you work in the cloud, keeping things organised is very important. Azure Policy is a simple tool that helps enforce rules on your resources. In this post, I’ll explain what Azure Policy is and show you a basic example of using it to require a tag on all your resources.

What is Azure Policy?

Azure Policy lets you set rules for your cloud resources. For example, you might want every resource to have a tag called Cost Centre so you know which department it belongs to. If someone tries to create a resource without that tag, the policy can stop it from being created.

This tool is very useful because it helps everyone on your team follow the same guidelines and keeps your cloud resources well organised.

A Simple Example: Requiring a "Cost Centre" Tag

In this example, we’ll create a custom policy that requires every resource to have a Cost Centre tag. If the tag is missing, the resource won’t be allowed.

Overview of the Steps

  1. Create the policy rule file.

  2. Create the policy parameters file.

  3. Create the policy definition in Azure using the Azure CLI.

  4. Assign the policy to a scope.

  5. Check if your policy is working.

Continue reading “How to Use Azure Policy for Better Cloud Management”

Unlocking Nested Virtualization in Azure: A Step-by-Step Guide

Azure

Nested virtualization in Azure is a powerful feature that enables running a Hyper-V hypervisor within an Azure virtual machine (VM). This capability is invaluable for developers, machine learning engineers, and data scientists who require flexible and scalable environments for testing, development, or containerized applications. This post provides a step-by-step guide to setting up nested virtualization, ensuring you can leverage its full potential.

Prerequisites and Supported VM Sizes

Before diving into the setup, ensure you choose an Azure VM that supports nested virtualization. Compatible VM sizes include:

  • Dv3, Dsv3
  • Dv4, Dsv4
  • Ddv4, Ddsv4
  • Ev3, Esv3
  • Ev4, Esv4
  • F2s_v2 to F72s_v2
  • FX4 to FX48
  • M series

For most use cases, the Dv3 and Ev3 series are excellent choices. Make sure the VM size meets the system requirements for your intended workloads, such as Docker Desktop.

Step 1: Deploying an Azure VM

  1. Create the VM:
    • Log in to the Azure Portal.
    • Select a Windows Server image and choose a compatible VM size.
  2. Configure Networking:
    • Set up the required inbound and outbound port rules.
  3. Deploy:
    • Review your configuration and deploy the VM.

Continue reading “Unlocking Nested Virtualization in Azure: A Step-by-Step Guide”