Fixing “HNS failed with error : Unspecified error” on docker-compose for Windows

The past few days I worked quite a lot with docker-compose on my windows machine and after something strange happened to my machine that crashed it, I was not able to start any containers anymore that had connectivity over the network with each other.

Every time I used the command-line docker-compose up, I would get a message telling me it failed to start the container. the full message I got was:

“ERROR: for web  Cannot start service web: failed to create endpoint aspnetblogapplication_web_1 on network nat: HNS failed with error : Unspecified error”

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Created an open source VSTS build & release task for Azure Web App Virtual File System

I’ve created a new VSTS Build & Release task to help you interact with the (VFS) Virtual File System API (Part of KUDU API of your Azure Web App). Currently this task can only be used to delete specific files or directories from the web app during your build or release workflow. It will be updated in the near future to also be able to list files or to upload / download files through the VFS API

The reason i made this task was that i needed it at my current customer. We’re deploying our custom solution to a Sitecore website running on Azure web apps using MSDeploy. The deployment consists of 2 parts: an install of the out-of-the-box Sitecore installation and the deployment of our customisations. When deploying new versions we want to keep the Sitecore installation and MSDeploy will update most of our customisations. Some customisations however create artifacts that stay on the server and aren’t  in control of the MSDeploy package that can cause errors on our web application. This new VSTS Build / Release task can help you delete these files. In the future this task will be updated with other functionality of the VFS API such as listing, uploading or downloading files.

The task is available in the VSTS Marketplace and is open source on github.

Let’s have a look how to use this task and how it works under the hood.
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Top 5 Ingredients for developing Cloud Native Applications

Introduction

Cloud Native Applications is a trend in IT that promises to develop and deploy applications at scale fast and cost-efficient by leveraging cloud services to get run-time platform capabilities such as performance, scalability and security out of the box. Teams are able to focus on delivering functionality to increase the pace of innovation.  Everything aimed to stay ahead of the competition. Companies such as Netflix and Uber disrupt their markets by leveraging cloud native capabilities to quickly introduce their products at a global scale. Adapt or die.

This article serves as the start of a serie of articles. The goal of this initial article is to explain the why and how of cloud native applications by defining the top 5 ingredients and their rationale. In follow-up articles, I will explain the ingredients in more detail.Read more →

Building, testing and deploying precompiled Azure Functions

Azure functions are great to build small specialized services really fast. When you create an Azure Functions project by using the built-in template from the SDK in Visual Studio you’ll automatically get a function made in a CSX file. This looks like plain old C# but in fact it is actually  is C# Script. When you’re deploying these files to Azure you don’t have to compile them locally or on a build server but you can just upload them to your Azure Storage directly.

In the last update for Azure Functions the option to build precompiled functions was added. Doing this is actually pretty simple. I’ve created a sample project on Github containing a precompiled Azure function, unit tests for the function and an ARM template to deploy the function. Lets go over the steps to create a precompiled Azure function.

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Understanding serverless cloud and clear

Serverless is considered the containers’ successor. But although it’s promoted heavily, it still isn’t the best fit for every use case. By knowing what its pitfalls and disadvantages are, it becomes quite easy to find the use cases which do fit the pattern. This post gives some technology perspectives on the maturity of serverless today.

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Lock Azure resources to prevent accidental deletion

In some cases you want to protect critical resources from accidental deletion. Some examples are a storage account with source data for processing, a Key Vault with disk encryption keys, or another key component in your infrastructure. When losing some resources that are key in your infrastructure, recovery can be dramatic. Resource Manager locks will enable you to protect these critical resources from deletion.

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Infrastructure as Code and VSTS

Your team is in the process of developing a new application feature, and the infrastructure has to be adapted. The first step is to change a file in your source control system that describes your infrastructure. When the changed definition file is saved in your source control system it triggers a new build and release. Your new infrastructure is deployed to your test environment, and the whole process to get the new infrastructure deployed took minutes while you only changed a definition file and you did not touch the infrastructure itself.

Does this sound like a dream? It is called Infrastructure as Code. In this article we will explain what Infrastructure as Code (IaC) is, the problems it solves and how to apply it with Visual Studio Team Services (VSTS).

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Microservices, not so much news after all?

A while ago at Xebia we tried to streamline our microservices effort. In a kick-off session, we got quite badly side tracked (as is often the case) by a meta discussion about what would be the appropriate context and process to develop microservices. After an hour of back-and-forth, we reached consensus that might be helpful to place a topic like microservices in a larger perspective. Below I’ll summarize my views on how to design robust microservices: start with the bigger picture, take time designing a solution, then code your services.

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Keep your ARM deployment secrets in the Key Vault

When creating new resource in Azure that have secrets like passwords or ssl certificates you can securely save them in the Key Vault and get them from the Key Vault when you deploy. Only the people who need access to the secrets can read and write them to the Key Vault. In a infrastructure as code scenario the secrets are supplied when deploying your templates to Azure. The code it self will be free of secrets.

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