Deploying a .Net Core web app to a Ubuntu Linux VPS

Evram Ehab

Published May 26, 2020

This tutorial assumes a fresh Ubuntu 20.04 (at the time of writing) VPS on GCP, e2-micro (2 vCPUs, 1 GB memory) (Free tier), and also assumes working from a windows machine, hence the below prerequisites.

Prerequisites

PuTTY (https://www.putty.org/) (For connecting to remote VPS over SSH)
WinSCP (https://winscp.net/eng/download.php) (For transferring files to remote VPS over SSH)
VS 2019
DotNetCore 3.1 SDK

Configuring the VPS: (Assume using sudo whenever needed)

Connect to VPS via SSH using PuTTY. (Use PuTTYgen to generate public and private keys to enable and secure connection, check [this](https://cloud.google.com/compute/docs/instances/connecting-advanced#windows-putty) article, and connect using the private key you saved, many articles illustrate how to do so with PuTTY)
Once connected, create a user that will be used to run your aspnetcore app and give them sudo permissions: (Assume this username is going to be vima91)

$ adduser vima91

$ usermod -aG sudo vima91

(I like to use vim for editing text files, but be free to use whatever text editing software you like) I will be installing vim at this point. Also, this is an awesome tutorial to get you started using vim:

$ sudo apt-get update
$ sudo apt-get install vim

To ensure there would be not problems next time you connect via ssh with the new user, let's edit the /etc/ssh/ssdh_config file:

$ sudo vim /etc/ssh/ssdh_config

And add these two lines:

PermitRootLogin no
AllowUsers vima91

Now save and restart ssh service:

$ sudo systemctl restart sshd

Now switch to this user, as we are going to use this user from here on:

$ su - vima91

Now we are ready to install .net core SDK. At the time of writing, the latest LTS is 3.1, let's first install package sources:

$ wget -q https://packages.microsoft.com/config/ubuntu/16.04/packages-microsoft-prod.deb
$ sudo dpkg -i packages-microsoft-prod.deb

And then install:

$ sudo apt-get install apt-transport-https
$ sudo apt-get update
$ sudo apt-get install dotnet-sdk-3.1

Then after it is finished, make sure it is installed by typing

$ dotnet --info

and checking version to be 3.1, should display something like this:

To create the folder that will have our app on the server, and give our user full ownership: (Assuming our app name is Mvc.Test)

$ sudo mkdir -p /var/www/Mvc.Test
$ sudo chown -R vima91:www-data /var/www/Mvc.Test

Now it is time to publish the app to the server.

Assuming you have the project on your windows machine, open and ready to launch, make sure you create a new public profile with the following settings:

- Type: FileFolder publish

- Configuration: Release

- Target Framework: netcoreapp3.1

- Deployment mode: Framework-dependent

- Target runtime: linux-x64

Now you are ready to publish, hit publish.
After publish is done, check the folder from which you need to copy the files:

<repo path>\bin\Release\netcoreapp3.1\publish

Open WinSCP and connect to your server using the same ways you used to connect via PuTTY, using the private key you generated and saved.
Copy the files from the above path to where we need our app to be on the server:

<repo path>\bin\Release\netcoreapp3.1\publish => /var/www/Mvc.Test

After copying is done, now we need to setup our reverse proxy, nginx.

First, let's install it:

$ sudo apt update
$ sudo apt install nginx

And let's run it:

$ sudo service nginx start

...and then make sure the nginx service is running:

$ systemctl status nginx

...and check that it is running. To double check, now if you navigate to your server's url/ip address, you should see the default nginx page, which would display something like this:

Now the fun part, let's configure nginx, open the config file:

$ sudo vim /etc/nginx/sites-available/default

You can clear all the file contents and paste this:

server {
    listen        80;
    server_name   localhost;
    location / {
        proxy_pass         http://localhost:5000;
        proxy_http_version 1.1;
        proxy_set_header   Upgrade $http_upgrade;
        proxy_set_header   Connection keep-alive;
        proxy_set_header   Host $host;
        proxy_cache_bypass $http_upgrade;
        proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header   X-Forwarded-Proto $scheme;
  } 

}

This means:

- server_name is localhost, meaning this will work only with the ip address of the server, with no domain name.

- listen on 80 means that the server will listen on port 80 (<your ip address to the server>:80) and reverse it to http://localhost:5000 (proxy_pass).

Now restart nginx:

$ sudo systemctl restart nginx

Now try to run the app with:

$ dotnet /var/www/Mvc.Test/Mvc.Test.dll

...should display something like this:

...and check if it is being served on your server ip address, should be served on port 80.

Now we need to run it as a service, so stop the current process (Ctrl + C) and type in:

$ sudo vim /etc/systemd/system/Mvc.Test.service

...and paste in this text:

[Unit]
Description=My application service


[Service]
WorkingDirectory=/var/www/Mvc.Test
ExecStart=/usr/bin/dotnet /var/www/Mvc.Test/Mvc.Test.dll
Restart=always
# Restart service after 10 seconds if the dotnet service crashes:
RestartSec=10
KillSignal=SIGINT
SyslogIdentifier=Mvc.Test
User=vima91
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false

[Install]
WantedBy=multi-user.target

...notice the user is set to `vima91` as it was decided this is the user that we will use to run the app, and this is also the user with full permissions on the app folder.

Now save the file and start the service that was just created:

$ sudo service Mvc.Test start

...notice the service name is `Mvc.Test`, this is taken from the file name `Mvc.Test.service`.

Now again try to navigate to your server ip address, your website should be up and running.

* Finally, to secure your website and install a certificate, visit Certbot (https://certbot.eff.org/lets-encrypt/ubuntufocal-nginx) to install a certificate, just follow the instructions and you are ready!

If you have a domain name, your nginx configration will slightly differ, and same with installing the certificate, but the articles and links provided will help you get up and running