Site moved back to Linux, again.

That’s the second time, lol. People fails in the same way huh?

I have used Azure Web Apps (on IIS) to host this website for more than 1 year and it turns out it is not good enough to run WordPress.

In the last year, the site was running in a very low speed. You may not observe it due to cache plugin, but I have to face it when publishing anything. The response time is around 20-60 secs for every process, proven by the chart displayed on the portal of Azure.

I also tried to use the Linux version of WordPress published officially using Azure Web Apps (on Nginx I guess). It’s faster, but still not fast enough, and the most critical is that’s not stable. Due to something unknown, it keep rolling config file back to the last version.

Finally, I decided to move all sites back to Nginx on Linux server without any SaaS solution. If you are facing this problem or want to host WordPress on Azure, you should consider to use a Linux server yourself instead of those official packages.

On more thing, there is another site powered by ShortUrl on the same web app, which need more time to move due to ShortUrl is built on DotNet Framework and is not able to run on Linux. My friend and I are rebuilt this program on DotNet Core 3 and it will be published on Github later.

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.

User of mysql/mariadb for wordpress

Today, I followed a guild to deploy a database using mysql and mariadb for wordpress instance. It failed in a strange way: I can use the user I created for the database to login from bash using mysql command, but wordpress reports access denied.

After a long time digging, the problem is solved:

Creating an account in database for wordpress, “mysql_native_password” is required to be specified, like CREATE USER [email protected] IDENTIFIED WITH mysql_native_password BY 'password'.

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.

Fix Catalina Beta boot cache problem (Little Snitch related)

If your app need to modify boot caches on macos, like Little Snitch, it may fail on macos Catalina beta version after macos updated from Software Update due to system bug.

 

Some app, like Little Snitch, need to update boot caches while installing. But due to bug introduced by Software Update of Catalina beta, it may fail. After reboot, you will get an error like “version mismatched” reported by Little Snitch.

 

To fix that, you need to boot into the recovery mode (CMD+R while booting), unlock your hard disk if you enabled FileVault, start Terminal from menu and enter:

touch /Volumes/<Volume>/System/Library/Extensions

and press enter. <Volume> is your hard disk volume. You can use ls /Volumes to check all mounted volumes.

This command will finish very fast. After it run, wait about 10 seconds and restart your computer. This will fix the boot cache problem.

 

 

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.