Overview⌗

This post provides a step-by-step guide on how to host a .NET Core API on Linux using the Hestia control panel. It covers everything from installing the necessary software to configuring the reverse proxy and systemd service.

Recently at work, I have been told that I’ll need to learn React so I can support the new applications that are being written in my department.

With that in mind, I thought I’d use my site as a testbed for this endeavor. A part of my plan to do this was to write an API that will serve the data for the site’s front end. So now I’ve created the need for me to understand not only how to design and write a maintainable API but also how I can host one on my Linux box. The simple answer and one I’ve done in the past is to write the API in PHP and be done with it.

But that would be too easy. I work as a DotNet developer, so it makes sense that I make this API in C# and use hosting it as a learning experience.

Getting Started⌗

Where to start? Well, I already have DotNet installed on my dev system from working with MonoGame, so that’s sorted. All I need to do is install DotNet on the hosting server and… What?

How do I get it to run? How do I access it from the outside world? All things I need to figure out. ONWARD!

DotNet Server Install⌗

Well, I’m running Ubuntu 22.04 (LTS), so this should be simple. Yep, here it is:-

sudo apt-get update && sudo apt-get install -y aspnetcore-runtime-7.0

Well, that was easy.

The Hestia Problem⌗

Okay, this is where my knowledge hits a brick wall. After some Googling, I found what I needed.

I use Hestia to manage my web install. I couldn’t just follow the Microsoft guides for how to set up Apache. But some enterprising chap has written up a script that, when installed in the Hestia proxy templates folder, will sort everything out for me.

The process is very simple. Clone the repository from hestia-netcore then copy the following files to the Hestia Nginx’s templates:-

netcore5000.sh - shell script that runs the app netcore5000.tpl - HTTP Nginx proxy template netcore5000.stpl - HTTPS Nginx proxy template

cp ./netcore5000.* /usr/local/hestia/data/templates/web/nginx/

Make sure the bash script has the proper run permissions:-

sudo chmod 755 /usr/local/hestia/data/templates/nginx/netcore*.sh

Make the Site⌗

Create a new site from the Control Panel. You’ll want to set up the TLS; however you do that. I use the Let’s Encrypt option. Once you have a working site to go to, you can select it and click on Advanced options, change the Proxy template to netcore5000.

Presuming you have your DotNet API to deploy and have built a Release version:-

dotnet publish --configuration Release

You can place your ASP.NET Core app in the netcoreapp folder, using the Hestia file manager.

At Your Service⌗

Now we need to create the service definition file:

sudo nano /etc/systemd/system/kestrel.service

Copy this into the file:-

[Unit]
Description=A wordy description of the service, something about DotNet

[Service]
WorkingDirectory=/home/%username%/web/%sitename%/netcoreapp
ExecStart=/usr/local/bin/dotnet /home/%username%/web/%sitename%/netcoreapp/%NameOfTheApp%.dll
Restart=always
# Restart service after 10 seconds if the Dotnet service crashes:
RestartSec=10
KillSignal=SIGINT
SyslogIdentifier=dotnet-api-name
User=www-data
Environment=ASPNETCORE_ENVIRONMENT=Production 
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false

[Install]
WantedBy=multi-user.target

Remember:-

  • Description - Should be changed to something relating to your app.
  • WorkingDirectory - %username% is the user you created the site under, and %sitename% is the domain name you created.
  • ExecStart - %username%/%sitename% same here but also %NameOfTheApp%.dll is the name of the project and is the entry point of your app.
  • SyslogIdentifier - should be something that means something when you look in the logs.
  • User - www-data is the user that the web server runs as; www-data is usually right.

To make the service start on boot-up, enable it:-

sudo systemctl enable kestrel.service

Start the service:-

sudo systemctl start kestrel.service

and verify that it’s running:-

sudo systemctl status kestrel.service

You should see something like the following:-

◝ kestrel-helloapp.service - Example .NET Web API App running on CentOS 7
    Loaded: loaded (/etc/systemd/system/kestrel-helloapp.service; enabled)
    Active: active (running) since Thu 2016-10-18 04:09:35 NZDT; 35s ago
Main PID: 9021 (dotnet)
    CGroup: /system.slice/kestrel.service
            └─9021 /usr/local/bin/dotnet /home/%username%/web/%sitename%/netcoreapp/%NameOfTheApp%.dll

With the reverse proxy configured and Kestrel managed through systemd, the web app is fully configured and can be accessed from a browser.

Testing⌗

Swagger is not part of the Release build, so you’ll have to test it another way. Might I suggest Postman? It has a free option that will allow you to test your API, but the best thing is to make sure it works before you launch it!

Conclusion⌗

Keep in mind that the proxy template netcore5000.sh runs the application on TCP port 5000, so that port will be unavailable for other applications to use. The developer suggests you use Unix Sockets instead or create different templates for different TCP ports.

Also, I haven’t looked into how insecure this setup is yet, and I reserve the right to completely change my mind about it later 😉.

Have fun 🧑‍💻