Creating AKS Node Count Grafana Panel with Azure Monitor

 AKS can be setup with automatic node scaling using VM scalesets in node pools. It will be useful to monitor how the nodes are scaling over time to have  a good insights, in to the AKS cluster nodes behaviour, while applications deployed in the cluster getting heavy traffic. We can enable monitoring AKS cluster with Managed Grafana in Azure with Azure Monitor and Log Analytics Workspace.  Let's look at query to setup node count over time panel in Managed Grafana in Azure using Azure Monitor.

Set Value for a Secret Variable in Azure Release Pipelines while Triggering from Another Release

 You might want to trigger a release from another release pipeline, specially if you are deploying to a multi tenant application environment. In such cases when you trigger a pipeline from another pipeline the variables you are setting dynamically cannot be a secret variable. If you set a variable that should be settable at release time as a secret, the release cannot be triggerd via the Azure DevOps REST API call, as it will throw an exception such as below.

The 'secret' property of

variables cannot be altered while creating a release. Verify the value

provided for variables UserPwd at scope Release and try again.  

Let's try to understand bit more of the requirement.

Resolve "encountered an error during hcsshim::System::CreateProcess: failure in a Windows system call: The system cannot find the file specified. (0x2)"

 As discussed in the post "Run .NET Core 3.1 Application with Windows Server Core 2019 Docker Image" there could be situations you need to setup .NET Core 3.1 on Windows servercore docker image. However, you might have experienced below error running Windows container, when you setup tools such as .NET runtime by yourself using dockerfile. 

Let's see one such example case and how it can be fixed with .NET Core runtime 3.1 installed on Windows servercore docker image.

Run .NET Core 3.1 Application with Windows Server Core 2019 Docker Image

 You would love to run your .NET applications as Linux containers instead of using Windows containers.  However, there are situations that you have to run your .NET applications as Windows containers with servercore docker image due to your project having dependencies, such as a third party dll (could be even built by different department in your company) which demands your application to run on Windows servercore docker image. Worst case is sometimes your app is still on .NET 3.1 Core you do not have a servercore image for .NET Core 3.1. (For .NET 5,6,7,8 the Windows servercore images are available.. check here)  Therefore you need to setup .NET Core 3.1 runtime on the servercore docker image. Let's see how we can achive this requirement.

Create Azure CNI based AKS Cluster with Application Gateway Ingress Controller (AGIC) Using Terraform

AKS clusters can be created with two networking types Kubenet (basic networking) and Azure CNI (advanced networking). If you are using Windows nodes as well in your AKS cluster you must use Azure CNI (Container Networking Interface).  Application gatway ingress controller is a great way to setup Ingress for AKS. Let's look at terraform code to deploy Azure CNI based AKS with AGIC.

Resolve "BadRequest message: error: code: InUseSubnetCannotBeDeleted" with Bicep IaC

 Bicep is really simple and easy to implement infrastructure as Code tool for Azure. However, there is a bit of an issue with subnet resource when we try to redeploy. Even without no changes Bicep is trying to delete and create subnet resources and cmplaining a subnet cannot be deleted, because the resources are using it. Let's try to understand the problem and a solution to fix the issue.

Create Deployment Groups Dynamically in Azure DevOps Release Pipeline

 Deployment groups are used in Azure DevOps classic release pipelines to define groups of targets an application should be deployed. We may sometime need to create these deployment groups dyamically based on the stage we are running in release pipeline. Let's look at the sample PowerShell code to use for creating depployment group dynamically, using Azure DevOps REST API, and how to use it in a pipeline.

Azure Redis Connectivity Checker App

Here is a simple .NET application to test connectivity to Azure Redis Cache. The application code is available in GitHub chamindac/RedisConnectionChecker. Refer the video for more details.