I am a bit confused with .NET core applications running on linux. For .NET core applications to run on linux, do we have to install .NET core on linux ? .NET core applications are cross-platform because of the run-time, does this run-time has to been installed on the linux machine first or will it be part of the .NET core application. How does run-time differentiate between different operating systems ?
It depends on how the application was published. You can do Framework Dependent Deployments, where the framework must be installed on the server. Or you can do Self Contained Deployments, where the necessary bits are bundled along with the app. More information is available in the documentation.
Related
I built an ASP.NET Core application, but I have a hosting server which allows .NET 4.7.2 version only.
Is it possible to deploy to that environment?
As #marc_s already said that you cannot run .NET Core on .Net xxx
run time as two version has it's own runtime and they are different in
regards of its architecture.
If you have a .NET Core application, depending on its version, you could choose your runtime.
Here is the official release of all .NET Core versions:
Note
If you have any requirement where you need to communicate both .NET Core xxx version along with the Classic .NET xxx version, there is a way to build a bridge between them that is .NET Standard library.
The main goal behind .NET Standard was to establish greater uniformity in the .NET ecosystem. You can get more details in the official document here
Hope above explanation guided you accordingly.
We are trying to run the .net core API service on Cent OS using Nginx server. Do we need .NET SDK or run time libraries are enough to run the .NET service on Linux?
It depends on how you are publishing the application.
If your application is published as a Framework Dependent application, it will need just the .NET Runtime to be installed.
If your application is published as a Self-Contained application, it will not need the .NET Runtime to be installed (but the transitive native dependencies of .NET runtime - such as OpenSSL and ICU might be needed).
At no point should the SDK be required to run the application. If it is, you are doing something wrong, or have run into a bug.
For more details, see:
.NET Application Publishing Overview
Publishing .NET applications with the .NET CLI.
If you are targeting Linux running Intel x86_64 machines, remember to use the linux-x64 Runtime Identifier when targeting the application.
I am struggling to understand how all these frameworks interact and depend on each other: .NET Core, .NET Framework, ASP.NET Core, MVC, etc.
This discussion leads me to believe that my MVC app uses ASP.NET Core and .NET Framework, but not .NET Core. If that's true, can I run the MVC app without the .NET Core runtime? If not, why is this app still dependent on the .NET Core runtime?
What I tried
I created a new project in Visual Studio 2017 as follows:
ASP.NET Core Web Application
MVC
.NET Framework
ASP.NET Core 2.1
I published the app as follows:
dotnet publish --self-contained false (to prevent the runtime from being included)
Deploy new ec2 instance with windows server 2019
Install minimal set of dependencies (IIS, .NET Framework, Rewrite Module)
Deploy the published app to IIS
The app did not work at this point. I got a 500.19 with error code 0x8007000d. I got it working by installing the Hosting Bundle. I manually removed a few things that were installed with the hosting bundle, and found that "Microsoft .NET Core 2.1.28 - Windows Server Hosting" is required. I don't know exactly what that is, but it smells to me like the .NET Core runtime is somehow involved here.
Update
When I install the Hosting Bundle, I see a few important things get installed:
C:\Program Files\dotnet\dotnet.exe
C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All\
C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App\
C:\Program Files\dotnet\shared\Microsoft.NETCore.App\
When I uninstall the .NET Core Runtime, I am left with just the following:
C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All\
C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App\
The app still works at this point. I assume what remains is the ASP.NET Core Runtime, which is different than the .NET Core Runtime. I am just looking to confirm that this app is only dependent on the ASP.NET Core Runtime and .NET Framework, and not at all dependent on .NET Core.
We have a system that has CPU, memory, disk, network card, IO devices, etc. We need a software to manage these resources for us and let us use this system. That software is the kernel. (say Linux)
Now that we can control the hardware we need abstraction on top of it for daily usage for users. We need shell, windowing system, different kind of services and daemons. We call this whole package the Operating System. (say Ubuntu)
Now that we can happily use our computer, we want to write our own applications for our problems or maybe for other's problems. The OS provides us with a programming language and a library of functions and system calls that we can use to create software, just like the OS itself is using them. (say C and glibc)
Suddenly we realize that our software is not portable to other Operating Systems and it has a lot of complex boilerplate codes. So we create a new programming language and provide a new set of library functions but this time way easier to read and understand. (say C# and .NET 5 SDK)
But we have a problem. Our OS does not understand this new language. So we need a layer between our language and the OS. This piece of software must read our program and somehow translate it for the OS. This program is the Runtime. (say .NET 5 Runtime)
OK, let's review. We create an app with C# and .NET. this results in a program that is in the IL language. OS does not understand IL language, therefore we need the .NET runtime to read our IL app and translate it for the OS. But how do we set this up?
We have two options:
We install the .NET runtime on every system that needs to run our app; this way our app becomes portable but it needs the runtime to work.
We include the runtime code inside our app; this way our app does not need the runtime but it won't be portable anymore and since it carries the runtime it will be larger.
Now to clear a few of your confusions:
What is the difference between .NET Framework and .NET Core?
.NET Framework only runs on Windows and has more libraries to use.
.NET Core is cross-platform and has fewer libraries to use but is very fast. It now goes with the name .NET 5 and those extra Windows-only libraries have been added to it.
What is the difference between .NET SDK and Runtime?
SDK provides you with the tools you need to build an app with (SDK includes the Runtime as well).
Runtime is lighter and just runs your app.
What is the difference between .NET Core Runtime and ASP.NET Core Runtime?
.NET Core runtime (.NET 5 runtime now) can only run your console apps and is lighter.
ASP.NET Core runtime can run your web apps.
There are also runtimes for GUI apps capable of running WinForms and WPF apps (Windows-only).
What is MVC?
Model-View-Controller is a design pattern and it is not related to a specific language or framework.
I have an ASP.NET Web application that was successfully running on Linux with the help of dnx-mono NuGet package. I used to publish it by using dnx publish tool and run it with the command:
/opt/dnx-mono.1.0.0-rc1-update1/bin/dnx --appbase /path/to/json Microsoft.Dnx.ApplicationHost kestrel
Since dnx is obsolete, I want to get rid of it and migrate to .NET Core, but it does not work anymore on Linux.
Important: I cannot make my application .NET Core app because it uses some libraries (like MySQL.Data) that are still not available for .NET Core. Therefore, I create ASP.NET Core Web Application (notice .NET Framework):
I migrated the whole application and run it successfully on Windows, but my target is Linux. No more dnx publish, no problem - there is dotnet publish which works well and produces binaries. What now? Dnx-mono package does not have a "dotnet-something" successor, and using dotnet command with published binaries produced errors that I was not able to resolve (The library 'libhostpolicy.so' required to execute the application was not found), but I don't think that I should even use dotnet command with standalone binaries. Googling didn't help as most tutorials are focused around ASP.NET Web applications for .NET Core, not for .NET Framework. Version of Linux is Debian 8, dotnet command was obtained by following this guide. Any clue?
You cannot run an application on Linux that targets the full .Net Framework, it has to be Core only.
In this video, Scott Hanselman interviews a guy from the ASP.NET team. He says that one of the goals of ASP.NET 5, on top of .NET Core, is that the apps won't depend on the .NET Framework and GAC assemblies on the hosting server. Instead, .NET Core libraries will be released via NuGet packages and apps will be deployed with their dependencies.
One of the reasons for this is so Microsoft can quickly release a bug fix or new feature, and we don't have to wait until the new version (of the full framework) is installed on our hosting environment.
My question is:
Are the apps built on .NET Core really independent of the version of .NET installed on the target machine, and can they run even without the .NET Framework installed?
Yes, the framework you use in your application is completely independent of the .NET Framework installed on the target server, because the Core .NET Framework is referenced via NuGet packages and can be bundled up for deployment via the DNX Utility, specifically of interest to you will be the dnu publish command.
Here is an excerpt, describing what dnu publish does:
Publish (dnu publish)
The publish command will package your application into a self-contained directory that can be launched. It will create the following directory structure:
output/
output/packages
output/appName
output/commandName.cmd
The packages directory contains all the packages your application needs to run.
The appName directory will contain all of your applications code, if you have project references they will appear as their own directory with code at this level as well.
So the .NET Core will exist in the output/packages directory and will not need to be installed on the target server.
A normal .net core app requires that you install .net core on the machine you wish to run the application on. There is a way to avoid this however, by publishing a self contained app. You can publish your app with the requisite version of .net core included. This will make your app larger, but if you only need one application on a machine to run .net, you need a specific version of .net, or you want to make a portable application, this is a good choice.