ASP .NET Core docker container warmup and liveness probes

Use a readiness probe to warmup your docker container and check the health of your container with a health probe

When running your ASP.NET core container/application you probably noticed that the first requests take longer on average. The cause of the longer request can be normal application loading and/or logic you have written that must initialize on your first call. It would be nice to warm up your container before a customer call is handled by your container. Kubernetes gives you the possibility to use a readiness probe to check and warm up your application.

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ASP.NET Core Web API custom formatters

Use accept headers to return new formats like CSV from an ASP.NET Core Rest service

postman csv

ASP.NET Core does support out of the box JSON, XML, or plain text formatters based on the ACCEPT Header. In this post, I’ll explain how to specify other formatters and return them based on the ACCEPT Header. As an example, I use a CSV formatter to return a CSV formatter. A controller method returns the format based on the ACCEPT Header which is specified by the client. This can be very useful in cases where you need to export your data to Excel, and the use of more formats makes your application more accessible.

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Hosting services in .NET Core console application

Building .NET Core console applications with IHost and HostBuild to take advantage of IHostedService, graceful shutdown, dependency injection, logging, configuration and more.

When building services for data processing you do not always need a user interface. An IHost is very capable of hosting such an application in a console application as headless service. The IHost does give you a number of advantages like graceful shut down, dependency injection, logging, and configuration. When running long processing tasks in Docker containers, graceful shut down helps you to keep the state of your application consistent. This post explains how making use of the generic IHost in .NET Core for headless services.

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HttpClient and HttpClientFactory in ASP.NET Core

Use the new HttpClientFactory to create HttpClient objects in ASP.NET Core. Learn how to create Named or Typed HttpClient instances.

With .NET Core 2.1 the HttpClientFactory is introduced. The HttpClientFactory is a factory class which helps with managing HttpClient instances. Managing your own HttpClient correctly was not so easy. The HttpClientFactory gives you a number of options for easy management of your HttpClient instances. In this post I’ll explain how to use the HttpClientFactory in your ASP.NET Core application.

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.NET Core, what is my OS

Check the operating system .NET Core is running on. Sometimes there are small differences when running on Linux or Windows. Discover your OS without exceptions.

There are a few cases where it is very useful to know the OS your .NET Core application is running on. One of those cases is when you need to set a time zone. Each OS does have its own naming of time zones. You can just try and catch the exception and then retry for another OS, however, if you know the OS, then it is far nicer to do this without exception handling.

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Injecting a Scoped service into IHostedService

Cannot consume scoped service ‘IScoped’ from singleton ‘Microsoft.Extensions.Hosting.IHostedService’.

In our projects we are using IHostedService to run background processes. What I have seen is that when injecting a scoped service into the IHostedService you get a InvalidOperationException on startup. The first time you get this exception, it is takes some time to figure out what is going on. This blog post will help you to resolve the problem faster.

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Run maintenance jobs on Azure SQL

Azure SQL, do not forget to schedule maintenance

Many users on Azure SQL Server do not realize they have to do their own maintenance on Indexes. This index will slowly become fragmented and the performance will decrease over time. Azure SQL does not have a Job scheduler (agent) like on premise. In this post I’ll describe how to schedule a maintenance job from an ASP.NET Core application.
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