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Create an Online Email Form with Azure Logic Apps

Saturday, August 20, 2016

After over a year in preview, Azure Logic Apps reached general availability last month. As part of the GA announcement, a new serverless consumption pricing model was added. This meant that Logic Apps no longer need to be part of an App Service Plan. Instead, we have a new pay-as-you-go pricing model that starts at $0.0008 per action execution (that's 8/100 of a cent) and gets even cheaper with volume.

Together, Logic Apps and Azure Functions now provide a really interesting story for serverless compute and workflow orchestration on Azure. The possibilities are endless.

Today we'll take a look at how we can build a simple online form and send an email using an Azure Logic App, all without writing a single line of server-side code.

We'll assume that we're adding a "contact us" form to an existing website. The form will make an AJAX call to a Logic App to send an email.

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Replacing MongoDB with Azure DocumentDB in a Node Application

Thursday, August 18, 2016

In March at the Build Conference, Microsoft announced MongoDB wire protocol support in DocumentDB. This means we can take existing applications that connect to MongoDB and run them on DocumentDB instead, using the same native MongoDB drivers. In this article we'll take a random Node/MongoDB sample app from the web and connect it to DocumentDB.

Why DocumentDB

DocumentDB is Azure's NoSQL database-as-a-service. Here are some of its advantages:

  • Fully managed - no VMs or database servers to manage, automatic backups
  • Highly available (99.99% uptime SLA)
  • Elastically scalable - scale storage and throughput up and down in seconds with no downtime
  • Super fast - 99% of reads/writes are guaranteed to be under 15ms

There are vendors that offer MongoDB as a service, but they are simply managing MongoDB in VMs for you. Now that DocumentDB supports the MongoDB protocol, it's effectively the first fully-managed, elastically-scalable MongoDB service.

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Coding for Readability

Monday, August 1, 2016

I think it's really important to write readable code. Readable code is easier to use, maintain, and reason about. It is also more difficult to create bugs in code that is readable.

I believe that code readability is more important than things like performance. That's not to say I don't care about performance, but I'd rather start with readable code and optimize where needed. A lot of readability problems in code often come from premature optimization.

Sometimes we write unreadable code simply because we don't know better. So I thought in this article I'd go through a few specific examples of how to make .NET code more readable. They're examples I've come across in code that I have written or reviewed.

TimeSpan Factory Methods

.NET's TimeSpan struct has four constructor overloads that take one, three, four, and five integer parameters. It's not uncommon to come across code like this:

var duration1 = new TimeSpan(1, 0, 0);
var duration2 = new TimeSpan(0, 1, 0, 0);

Both of these statements create a TimeSpan of 1 hour. But unless you have memorized the different constructor overloads or use IntelliSense, it is near impossible to figure out what the actual value is by reading it.

One might say we can solve this by giving the variables a proper name. I think it's incredibly important to give variables meaningful and descriptive names, but that can only get us so far. Take this example:

var oneHour = new TimeSpan(0, 0, 1, 0, 0);

What's wrong with this? Well, it turns out the signature of this particular overload is public TimeSpan(int days, int hours, int minutes, int seconds, int milliseconds); so we have a TimeSpan of 1 minute, not 1 hour. Whoops!

A better way to solve this is using TimeSpan's static factory methods:

var oneHour = TimeSpan.FromHours(1);
var fiveMinutes = TimeSpan.FromMinutes(5);

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.NET Fringe 2016 Recap

Sunday, July 31, 2016

Three weeks ago I attended and spoke at .NET Fringe in Portland, OR. I fell in love with the conference and the city. It was an amazing experience.

Saturday, July 9

Geek Train

The .NET Fringe Geek Train from Seattle to Portland was a great way to kick off the conference. Adron Hall organized it and met us at Seattle's King Street Station with our tickets.

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ASP.NET Web.config Transforms in Docker Containers

Wednesday, June 29, 2016

In the last article, we walked through how to run an ASP.NET 4.6 application in a Windows Server container. In that example, we didn't have a way of applying environment-specific transformations to the Web.config. Today we'll look into how to do that.

Environment Variables in Docker

If the exact same Docker image is deployed to different environments, how do we manage environment-specific settings in each running container? The answer to this is environment variables. When we first start up a Docker container (e.g., using docker run), we can pass one or more environment variables to the container. These variables are available to the application or script that is launched as the entrypoint of the container.

In ASP.NET 4.6 and earlier, it's common to use configuration transformations to change values in the Web.config to the correct settings for the environment. When we start a container for the first time, we can pass an environment variable into the container to signal which config transformation to apply.

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