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.
Continue reading “ASP .NET Core docker container warmup and liveness probes”
Use accept headers to return new formats like CSV from an ASP.NET Core Rest service
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.
Continue reading “ASP.NET Core Web API custom formatters”
Building .NET Core console applications with IHost and HostBuild to take advantage of IHostedService, graceful shutdown, dependency injection, logging, hostbuilder, 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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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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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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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.
Continue reading “Injecting a Scoped service into IHostedService”
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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Only a few years back Windows Communication Foundation (WCF) was the way to do communication on the Microsoft platform based on SOAP protocol. Now a days new services are mostly build on top of Representational State Transfer (REST) Services. Sometimes you have to access a ‘legacy’ SOAP services for .NET Core. .NET Core has limited WCF support. In this blog post I’ll explain how to consume SOAP services form .NET Core.
Continue reading “Access XML SOAP services in .NET Core and client certificates (SSL)”
In the previous blog post called background tasks with ASP.NET Core using the IHostedService Peter described how to use the IHostedInterface for background tasks. In this post, we continue on this subject and add some pointers on how to perform scheduled background tasks.
In many software projects, there are repetitive tasks; some do just repeat every x seconds after the last instance is finished but you might also have to run a task on a schedule like every 10 minutes. When building repeating or scheduled tasks there are many options on how to approach the scheduling and this approach can be influenced by a number of technical choices.
Building the scheduling yourself is an option when you do not want to add extra dependencies to your project, have full control or just want an extra technical challenge. An out of the box solution you can a look at Hangfire, Quartz.net, or an external service that does an http call every x seconds to trigger the task (something like Pingdom).
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In the past weeks we have upgraded our ASP.NET Core 2.0 project to 2.1. The main reason for the upgrade is using the latest signalr capabilities and hosted services. The issues we had are related to the features we use. In our case the upgrade encountered some minor issues. In this blog post I’ll show what we had to change and give some tips on how to upgrade.
Continue reading “Upgrade ASP.NET Core and Entity Framework Core 2.0 to 2.1”