Building a simple PicPaste replacement using Azure Web Apps and WebJobs

This post was supposed to be an introduction to Azure WebJobs, but it took a weird turn somewhere and became a guide to building a simple PicPaste replacement using just a wimple Azure Web App and a WebJob.

As such, it might not be a really useful app, but it does show how simple it is to build quite powerful things using Azure.

So, what is the goal? Well, the goal is to build a website that you can upload images to, and then get a simple Url to use when sharing the image. This is not complicated, but as I want to resize the image, and add a little overlay to it as well before giving the user the Url, I might run into performance issues if it becomes popular. So, instead I want the web app to upload the image to blob storage, and then have a WebJob process it in the background. Doing it like this, I can limit the number of images that are processed at the time, and use a queue to handle any peaks.


DotNetRocks with Carl Franklin and Richard Campbell

A while back, at NDC Oslo, I was approached by Carl Franklin and Richard Campbell regarding joining them for an episode of their podcast DotNetRocks. Obviously I said yes without hesitating! Who wouldn’t!? Unfortunately there were some scheduling problems, so we couldn’t do it during NDC. So instead, we did it over Skype a week or so later. And it has now finally been published on the DotNetRocks website.

The topic for the episode is the SOLID principles, which I have been talking about at quite a few conferences now. It was nice talking about these principles under these relaxed circumstances, without getting some of the flaming that I get ever so often for being a bit too pragmatic about the whole thing. Hopefully people will enjoy listening to it, and get some thoughts and ideas about how to work with SOLID in there projects. So go ahead and have a listen at

Integrating a front-end build pipeline in ASP.NET builds

A while back I wrote a couple of blog posts about how to set up a “front-end build pipeline” using Gulp. The pipeline handled things like less to css conversion, bundling and minification, TypeScript to JavaScript transpile etc. However, this pipeline built on the idea that you would have Gulp watching your files as you worked, and doing the work as they changed. The problem with this is that it only runs on the development machine, and not the buildserver.… I nicely avoided this topic by ending my second post with “But that is a topic for the next post”. I guess it is time for that next post…

So let’s start by looking at the application I will be using for this example!


Integrating with Github Webhooks using OWIN

For some reason I got the urge to have a look at webhooks when using GitHub. Since it is a feature that is used extensively by build servers and other applications to do things when code is pushed to GitHub etc, I thought it might be cool to have a look at how it works under the hood. And maybe build some interesting integration in the future…

The basic idea behind it is that you tell GitHub that you want to get notified when things happen in your GitHub repo, and GitHub makes sure to do so. It does so using a regular HTTP call to an endpoint of your choice.


Trying to understand the versioning “mess” that is .NET 2015

Right now there is a lot of talk about the next iteration of the .NET platform, and the different versions and runtimes that is about to be released. Unfortunately, it has turned into a quite complicated situation when it comes to the versions of things being released.

I get quite a few question about how it all fits together, and I try answering them as best as I can. However, as the question keeps popping up over and over again, I thought I would sum up the situation as I have understood it.

Disclaimer: Everything in this post is “as I have understood it”. I am not working for Microsoft, and I am in no way or form guaranteeing that this is the right description. This is just how I understand the situation. Hopefully it is fairly close to the real world.


ASP.NET 5 demo code from SweNug

As promised during my talk at SweNug Stockholm last week, I have now uploaded my code for anyone to play around with. I just want to highlight that it is based around VERY early bits, and new versions might cause problems. It is built using runtime 1.0.0-beta5-11533. But even if it changes, the code should give you a clue about how it works.

Code is available here: ASP.NET 5 (714.47 kb)

Getting the ASP.NET 5 samples to work on Windows with the “new” dnvm (and beta 5)

[UPDATE] If you clone the dev branch’s samples instead of the master branch, it should be easier. You will still need to update the Startup.cs file for now though. Pull-request made… (That was a long blog post to no use…still gives some insight into how it works though…) [END UPDATE]

[UPDATE 2] Now updated to beta-5 if anyone still wants it considering the update above… [END UPDATE 2]

Yesterday I finally had time to sit down and play with the new ASP.NET 5 runtime, which is something I have wanted to do for quite some time. However, it kind of annoyed me that I couldn’t just install the ASP.NET 5 runtime, clone the samples from GitHub and get started, as it generated a whole heap of errors. After an hour or so of Googling and trying things out, I finally got it working, so I thought I would write down what I did to get it to work.

Note: This codebase is moving ridiculously fast, so this post is going to be old within a very short while. Everything is based on the code as of today, March 20th 2015.


Understanding OWIN (Katana) Authentication Middleware

As some of you might have noticed, I really like OWIN. I like the simplicity, and the extremely powerful things that you can do with it in a simple way. And the fact that I don’t have to create an IHttpModule implementation, and figure out the ASP.NET event to hook into, like I had to to do the same thing before OWIN.

Katana, Microsoft’s implementation of OWIN, also offers a standardized way to handle authentication. And it is really easy to use, and not too hard to extend to work with your own identity providers. However, being me, I want to know how it works “under the hood”, and not just read a “how to build an authentication middlware” blog post…

Remember, knowing how things work “under the hood”, or “under the bonnet” if you speak the Queens English, makes it possible to do more things than just use it. By knowing how a combustion engine works (under the hood/bonnet of your car), makes it possible to add a turbo or two to it, or a compressor, or at maybe tweak the fuel consumption and horse power you get from it. But let’s leave the car analogies and look at Katana authentication middleware.


Uploading files using ASP.NET Web Api

I have once again been tasked with writing a ASP.NET Wep Api action to handle the upload of a file. Or rather a form including a file. And once again, I Googled it looking for good solutions. And once again I got the same code thrown in my face over and over again. It seems to be the only one out there. And it isn’t what I want…

The code I am talking about is the one available at,-part-2. And if you don’t want to go and read that, the general gist is this

if (!Request.Content.IsMimeMultipartContent())
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);

string root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);

await Request.Content.ReadAsMultipartAsync(provider);

/* Get files using provider.FileData */


Building a “front-end build pipeline” from a C# devs perspective - Part 2

In the previous post, we looked at how we can use Gulp to run tasks for us. And in that post we used it to create tasks for transpiling LESS and TypeScript into CSS and JavaScript. But the example was very small and simple. It only contained 1 LESS file and 1 JavaScript file. But what if we have more than 1? Well, that’s when we need to start bundling the files together, and potentially minify them so that they are faster to download. Luckily, this is a piece of cake to do using Gulp. So in this post, we will have a look at how to do that, as well as how to get some TypeScript/JavaScript tests thrown in there as well.

Dislaimer: The solution will still be VERY small and simple. But at least it will be made big enough to be able to use bundling and minification. Which to be honest just means that we need more than one file of each type…

I assume that you have read the last post, and that if you are following along on your machine, you will need to be done with everything that was done in that post…