Erwin Staal

DevOps Engineer & Azure Architect

Passing variables between stages in Azure DevOps pipelines
March 3, 2022

Passing variables between stages in Azure DevOps pipelines

The other day I was working on an Infrastructure as Code project that involved deploying an Azure Container registry. That ACR is typically a resource that you deploy just ones in your production environment and not one per environment. You do that because you want container images to be used as immutable artifacts that are progressively deployed across all your environments.

Terraform Azure DevOps to Azure example pipeline

Terraform Azure DevOps to Azure example pipeline

February 14, 2022

I finally had the opportunity to work with Terraform on one of my recent projects. I have been building Infrastructure as Code with ARM templates or Bicep for years. Together with two friends, I even wrote a book on that! Terraform was always on my list of tools to work with. I had played around with it a little in my spare time but never got the opportunity to put it to use in an actual project. This blog will help you get started!
Functions in ARM Templates

Functions in ARM Templates

October 16, 2021

To help build templates quicker, make them more expressive and reusable, there are many built-in functions at your disposal. And even if there isn’t a built-in function for your specific scenario, you can always write one on your own. The use of functions introduces pieces of logic into your templates, which can be used from expressions.
Automatically renew the image used in an Azure DevOps private agent

Automatically renew the image used in an Azure DevOps private agent

July 25, 2021

In a previous post, I wrote about creating your own hosted Build and Release agents in Azure DevOps. That process could be improved by regenerating the VM image, for example, every month. By doing that, you stay up-to-date with both the latest versions of all the tools installed as well as with security patches. This post will describe how to do that using an Azure DevOps pipeline which will be triggered monthly.
Configure Azure Security Center using Bicep

Configure Azure Security Center using Bicep

June 25, 2021

At a few of my recent clients, I’m working on moving their infrastructure to code using Bicep. Part of that is always the configuration of Azure Security Center. Things to configure are, for example, the services for which you want to enable Azure Defender or the email notifications. This blog will describe how to do just that.
ARM template: getting deeply nested resource properties

ARM template: getting deeply nested resource properties

March 15, 2021

The other day I was deploying a private endpoint connected to a KeyVault using an ARM Template. By using a Private Endpoint one can assign a private IP address from your own Virtual Network to an Azure PaaS service like KeyVault, SQL, storage accounts, and others. To resolve the private IP using the service FQDN from within the VNET, I also needed to set an ‘A’-record in the private DNS zone.
Database per tenant infrastructure

Database per tenant infrastructure

February 25, 2021

The previous two posts in this series talked about the infrastructure and the setup of the catalog database and how to run migrations on that. This post will dive into the code that allows you to connect to a specific database of a tenant. This blog is part of a larger series of blogs in which I explain how to set up a database-per-tenant architecture. Most of what this blog touches can still be used without reading the whole series.
Database per tenant infrastructure

Database per tenant infrastructure

February 25, 2021

The previous two posts in this series talked about the infrastructure and the setup of the catalog database and how to run migrations on that. This post will dive into the code that allows you to connect to a specific database of a tenant. This blog is part of a larger series of blogs in which I explain how to set up a database-per-tenant architecture. Most of what this blog touches can still be used without reading the whole series.
Manual approval in an Azure DevOps YAML-pipeline

Manual approval in an Azure DevOps YAML-pipeline

January 31, 2021

Last week I was creating a YAML-pipeline in Azure DevOps to deploy some ARM Templates. Before deploying those changes to my production environment, I wanted to have a manual approval in place. Here’s how I did that.
Entity Framework Core and Migrations

Entity Framework Core and Migrations

December 17, 2020

Entity Framework could be a logical choice when building a .NET Core API that needs to talk to a database. In this blog, I’ll show you how to get started with EF and Migrations. We will create the models, the DbContext, and the migrations needed to upgrade your database when introducing changes. We will also see how we can deploy those changes in your Azure DevOps pipeline on each release.
Database per tenant infrastructure

Database per tenant infrastructure

November 25, 2020

In the first post in this series, we’re going to talk about the infrastructure. We need some database server to host each tenant’s database and the shared database that contains information on all the tenants (like which database belongs to whom). We also need infrastructure to host the API on and off course, need something for configuration and secret management. TL;DR: All templates and the pipeline can be found in my repository.
Multi tenant app with database-per-tenant

Multi tenant app with database-per-tenant

November 15, 2020

I recently started building an architecture for a multi-tenant app to support a database per tenant (customer) scenario for one of my customers. Splitting your data in multiple databases like that has a few benefits like easy backup and restore per customer, better security by separation of data, and potential performance benefits. Especially the separation of data was a hard requirement here. I found this to be a nice challenge as it involves many moving parts to get it right.
Using an Azure Virtual Machine Scale set as Azure DevOps agents

Using an Azure Virtual Machine Scale set as Azure DevOps agents

October 2, 2020

Over the past few weeks, I’ve been implementing a few new networking features in Azure for a client. We did that to make our infrastructure more secure. I’ve been playing around with VNET’s, Private Links, Services Endpoints and Access Restrictions on Azure Web App, SQL databases, Storage and KeyVault. One of the issues I stumbled upon quite quickly was the fact that when you restrict access to a resource, Azure DevOps can’t reach that anymore as well.
Disable Azure Security Center recommendations using ARM Templates

Disable Azure Security Center recommendations using ARM Templates

September 8, 2020

Azure Security Center gives you a great overview of the state of your workloads security hygiene and compliance. I recently got tasked with going through the recommendations, take action, and improve our overall security and compliance status. Some of the recommendations presented to me were in the ‘Enable advanced threat protection’-group, like ‘Advanced threat protection should be enabled on Azure App Service plans’.
My first look at Azure IoT Hub

My first look at Azure IoT Hub

September 3, 2020

I recently decided it was time for me to take a shot at passing another few Microsoft exams. While studying for one of them, I noticed that I didn’t knew too much about Azure IoT Hub. I had never come across it in my daily job. So I gave myself the following goal: have something that acts as an IoT device that sends data into Azure IoT Hub and have something read that data and does something useful with it. When talking about the data that comes out of IoT Hub we usually split that into a hot and/or cold analytics path, in this blog I’ll show you an example of both.
Generating API clients using NSwag and Azure DevOps

Generating API clients using NSwag and Azure DevOps

August 10, 2020

Whenever you create an API you probably want to be able to create some documentation around that API. Swagger has been around for a long time and allows you to explore and test your API using a nice UI in the browser. It also provides you with an OpenAPI spec in json format describing your service. OpenAPI is to REST what WSDL is to an SOAP-endpoint. Wouldn’t it be cool if you could generate your clients using that spec? Well, you can!
Azure App Configuration and KeyVault

Azure App Configuration and KeyVault

July 26, 2020

Recently I started on a new project and therefor a whole new application. It’s build using .NET Core and like many apps, it needs some configuration that varies between deployments. Azure now has a service called Azure App Configuration that allows you to store and manage your configuration. Combined with Azure KeyVault to store your secrets, we get configuration management nearly for free. Let’s dive in!
Autoscaling .NET Core Azure Functions on Kubernetes

Autoscaling .NET Core Azure Functions on Kubernetes

June 16, 2020

Everyone who worked with containers on Kubernetes probably agrees that there is a pretty steep learning curve in the beginning. Once you overcome that, you’ll find that it’s an awesome and very capable product and that it will make your life better (when used in the right context of-course). One area where Kubernetes is not so great is event-based autoscaling. That’s where KEDA comes in. KEDA stands for Kubernetes-based Event-driven Autoscaler.
Securing your Azure SQL DB using Azure Private Link

Securing your Azure SQL DB using Azure Private Link

May 27, 2020

Whenever you create a new SQL Database on the Azure Cloud, one of the first things you probably do is set the ‘Allow Azure services and resources to access this server’-switch to ‘Yes’. This allows your App Service for example to access your database. It’s not very secure however since all an attacker then needs is your connections string. And although you are probably very careful with that, it might just accidentally get public.
Using an ARM template to deploy your SSL certificate stored in KeyVault on an Web App

Using an ARM template to deploy your SSL certificate stored in KeyVault on an Web App

October 20, 2019

Everyone knows it’s completely normal nowadays to have your website loaded over https. Troy Hunt explains why. There are quite some examples out there on how to use Let’s Encrypt certificates on your Azure web app, see this one by Henry Been for example. For most of us that’s a perfect and free solutions. It doesn’t work for all of us however.
Reading secrets from KeyVault in your Azure Cloud Service

Reading secrets from KeyVault in your Azure Cloud Service

October 18, 2019

Azure Cloud Service was one of the earliest Platform as a Service offerings by Microsoft Azure. With Cloud Services you can run web applications or run background applications. Since it is a PaaS offering, you dot not need to worry about the issues that comes with IaaS, patching for example and they offer a lot of flexibility. They are not officially deprecated, though Microsoft is pushing for the use of other PaaS offerings.
Reading secrets from KeyVault in your Azure Web App

Reading secrets from KeyVault in your Azure Web App

October 18, 2019

Azure KeyVault is a great Azure offerring that allows you to store for example secrets or certificates. You are currently looking at the first post out of a series of posts on how to grab secrets or certificates from KeyVault in your web applications. This post wil focus on creating the KeyVault, giving access to you Azure Web App and retrieving a secret in two different ways. I will be using an ASP.
My k3s OpenFaaS Raspberry Pi cluster

My k3s OpenFaaS Raspberry Pi cluster

September 10, 2019

A few months ago I build a Raspberry Pi cluster running K3S. I build it because I wanted to have a nice environment the learn more about Kubernetes and OpenFaas. It always feels nice to have something you can actually touch in this all software world I normally live in. After tweeting and giving a session about my OpenFaas Raspberry Pi cluster people started asking what parts the cluster consists of and what software I use to run it.
Creating a simple OpenFaas template

Creating a simple OpenFaas template

May 11, 2019

Whenever you want to create a new function to run on OpenFaas your starting point would be an OpenFaas template. OpenFaas has a template engine build-in which can create new functions in a given programming language. There are the official/default templates and there are templates in the store provided by the community. If a language you would like to use isn’t available or it doesn’t suite your needs, you can always write your own!
Your first .NET Core Serverless function on OpenFaas

Your first .NET Core Serverless function on OpenFaas

May 8, 2019

In my previous blog I described how to set-up OpenFaas on a Kubernetes cluster with a little help from Rancher. Now it’s time to deploy our first serverless function. In this blog we’ll create and deploy a .NET Core function that reads a bit of config using both an environment variable and Kubernetes secrets. Creating your first function In the previous blog we installed the OpenFaas cli. If you didn’t already, here are the instructions.
Markdown Syntax Guide

Markdown Syntax Guide

March 11, 2019

This article offers a sample of basic Markdown syntax that can be used in Hugo content files, also it shows whether basic HTML elements are decorated with CSS in a Hugo theme.
Rich Content

Rich Content

March 10, 2019

Hugo ships with several Built-in Shortcodes for rich content, along with a Privacy Config and a set of Simple Shortcodes that enable static and no-JS versions of various social media embeds.
Octopus Deploy and Entity Framework migrations

Octopus Deploy and Entity Framework migrations

February 3, 2017

A step that is very common in almost every deployment pipeline is the migration of the database. In this blog I’ll show you how to do this using Octopus Deploy and Entity Framework Migrations. I’ll be using a very simple ASP.Net MVC application called SimpleMVCApp. In the same solution, I’ve created a library project named SimpleMVCApp.Data in which my context, models, migrations and migration scripts reside. This application can be found on my GitHub account.
Continuous delivery bij SnelStart

Continuous delivery bij SnelStart

December 22, 2016

Bij SnelStart ontwikkelen we boekhoudsoftware voor het midden en klein bedrijf. SnelStart doet dat al meer dan 30 jaar door middel van een desktopapplicatie en sinds kort ook met een online variant. Ongeveer drie jaar geleden zijn we bij SnelStart begonnen met de ontwikkeling van ons service platform. Dit is een Azure Cloud oplossing die onze klanten onder andere de mogelijkheid geeft om in te loggen vanuit hun desktop- of webapplicatie, online administraties aan te maken en belastingaangiften te versturen.