Deploy a dotnet core site on nginx and systemd

This article is about how to deploy an ASP.Net core 3.1 site on nginx and systemd.

Preparation:

  • Prepare a server with nginx and systemd.
  • Install dotnet core support on server. Please check Microsoft site for details.
  • Build the binary files of the site to be deployed.

Step 1: Upload files

Make a folder in the server to be used to store site files. This folder will be marked as <SITEPATH> in all files below.

Upload your site files into this folder.

Give the permission to this folder.

sudo chown -R www-data:www-data <SITEPATH>
sudo chmod -R 755 <SITEPATH>

Step 2: Create systemd service

Create a service file. I suggest to put this file in the same folder of the site, aka <SITEPATH>. Let’s name it as myapp. You could change the name.
nano <SITEPATH>/myapp.service and enter this text below:

[Unit]
Description=<A_DESCRIPTION_TEXT_HERE>

[Service]
Environment=ASPNETCORE_URLS=http://localhost:<PORT_NUMBER>
Environment=ASPNETCORE_ENVIRONMENT=Production
WorkingDirectory=<SITEPATH>
ExecStart=/usr/bin/dotnet <SITEPATH>/<ENTRY_FILE>.dll
SyslogIdentifier=<A_NAME_HERE>
Restart=always
RestartSec=10
KillSignal=SIGINT
User=www-data

[Install]
WantedBy=multi-user.target

You should specify the description, port number, site path, entry file (main file), and the name to be used in syslog. Port number need to be different than all used by other services.

Link the file to systemd folder by ln -s <SITEPATH>/myapp.service /etc/systemd/system, reload systemd by systemctl daemon-reload, then start the service by systemctl start myapp.service. If everything goes will, you can see the port is listed in lsof -i -P -n | grep LISTEN. At last, set this service to start with system by systemctl enable myapp.service.

Step 3: Create nginx site.

Create the site file in sites-available folder by nano /etc/nginx/sites-available/<YOUR_SITE_NAME>, and enter this text below:

server {
    listen 80;
    listen [::]:80;
    server_name <SERVER_DOMAIN>;
    
    location / {
        proxy_pass http://localhost:<PORT_NUMBER>;
        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;
    }
}

You should specify the server domain name and the port number which is chosen for this app.

Link the file to enabled sites by ln -s /etc/nginx/sites-available/<YOUR_SITE_NAME> /etc/nginx/sites-enabled. Test config by nginx -t. If there is nothing wrong, apply the setting by systemctl reload nginx.

Further: Certbot

If you want to use certbot to apply a free ssl certificate to this site, the nginx plugin shipped with certbot can handle that without any problem. Use certbot with the nginx parameter to finish this job: certbot --nginx.

Generate password node for SoftEther config file

Recently, I wrote an C# project for connect all devices from clients of my company to the server for remotely fault detection. SoftEther is chosen for underlying network solution.

The maintenance engineers don’t want to use the GUI of SoftEther to create profiles for each clients. A project is required for generating config files.

The only problem is how SoftEther store the password. I dig a lot and got the answer.

  • Password is encrypted by SHA0 on password + USERNAME in capital.
  • NTLM related password is encrypted by MD4.

 

Here is the password node generating project, based on C#, dotnet core 3. Actually, the code is tested on dotnet core 2 and netfx 4 also.

GPIO support is not fully launched in dotnet core 3 currently

I’m developing using dotnet core on Raspberry Pi.

After the dotnet core 3 launched finally, I rushed to the released version from the preview one. Some package I used, like System.Devices.Gpio, was published in dotnet-corefxlab under myget. Now I can find it on nuget.

But, sadly, the current version of System.Device.GPIO (not Devices, but Device) in nuget seems contains only abstract classes. The UnixSpiDevice, GpioPin and something useful are missing in the version of nuget. Now I have to turn back to use the preview version on myget.

Good thing to know is, the preview version of Gpio supports dotnet core 3 with no problem.

MSDN Magazine

It says MSDN Magazine is ending soon.

Here is the MSDN Magazine collection hosted on my OneDrive. Password is “secretnest.info” without quotes.

All files are mainly downloaded from official site. The missing (2018 Jan / Connect) and not published (2019 June / July) are from my received emails (subscribed version). I will update the rest when they are published.

I attached some main tech involved at the file name.


Update:

The final issue of MSDN Magazine is published.

 

The issues listed below are replaced by the versions from emails due to reason specified.

  • 2018 Jan version: Wrong link to 2017 Jan.
  • 2018 Connect(); Missing link
  • 2019 July: 404 link
  • 2019 October: Not published yet.
  • 2019 November: Not published yet.

Bug and workaround in dotnet MEF — The export is not assignable to type .

Today, while writing an app use netfx 4.8 with MEF support based on System.ComponentModel.Composition 4.5 from nuget, a strange bug hit me.

Because I’m not treat MEF as essential, I’d like to write the main code in a project and create MEF wrap in another one like:

  • In Project A: class Real : InterfaceA
  • In Project B: class MEFWrap : Real, and marked with Export attribute.

Certainly, Project A is referenced by Project B.  While building the solution, both dlls generated from Project A and Project B are placed in the output folder of Project B.

While trying to use MEF to load the class from Project B, the funny thing happened:

  • If AssemblyCatalog is chosen to create the object, from the assembly object loaded by LoadFrom method, nothing is wrong, but
  • If AggregateCatalog is used with all assemblies loaded from the folder (Project A and Project B) at the same time, an exception raised while calling ComposesParts:

    The export InterfaceA is not assignable to type InterfaceA.

I don’t know why it’s happened but here are 2 ways to get avoid of it.

  • Only load assembly Project B, not both of them, if it’s possible, when you know the name or name pattern while searching files, or
  • Using AssemblyCatalog for each file, instead of using AggregateCatalog as a whole, will also works.