Installation as a Web Server for Linux – Quickstart

Download the CODESYS 4 Debian package from the CODESYS Store.

Install the CODESYS 4 Debian package.

sudo apt install ./codesys-4_[your version]_[your architecture].deb

Create the group codesys-4 and the user c4-server. These are necessary to start the server and log in to the application.

In the following example, an additional test user named hugo will be created and added to codesys-4 group. This user will be able to log in to the application later. This is optional. For testing purposes, you could also simply add an existing user to the codesys-4 group.

In /etc/systemd/system/, create a file named codesys-4.service. Replace nano with your preferred editor.

sudo nano /etc/systemd/system/codesys-4.service

Edit the file as follows:

[Unit]
Description=CODESYS 4 Server
 
[Service]
Type=exec
WorkingDirectory=/opt/codesys-4/
ExecStart=/opt/codesys-4/c4-server --port 8080
Restart=always
# Restart service after 10 seconds if the dotnet service crashes:
RestartSec=10
KillSignal=SIGINT
SyslogIdentifier=codesys-4-server
User=c4-server
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false
 
[Install]
WantedBy=multi-user.target

Start the systemd unit which you just created:

sudo systemctl start codesys-4

Also set the unit to enabled to automatically start the server at system startup:

sudo systemctl enable codesys-4

Install the nginx package if it has not already been done:

sudo apt update && sudo apt install -y nginx

To enable HTTPS communication, you need to create a temporary self-signed certificate and a key.

For testing purposes, create a private key and a certificate for the reverse proxy:

Create the configuration for the reverse proxy. Replace nano with your preferred editor.

sudo nano /etc/nginx/sites-available/codesys-4

Create the following configuration:

# See https://docs.microsoft.com/en-us/troubleshoot/developer/webapps/aspnetcore/practice-troubleshoot-linux/2-2-install-nginx-configure-it-reverse-proxy
# for more information.

server {
 listen	443 ssl;
 listen	[::]:443 ssl;
 ssl_certificate /etc/ssl/certs/codesys-4-certificate.crt;
 ssl_certificate_key /etc/ssl/private/codesys-4.key;

 #server_name _;
 server_tokens off; # see https://nginx.org/en/docs/http/ngx_http_core_module.html#server_tokens

 location / {
 rewrite ^/$ /index.html last;
 proxy_pass http://127.0.0.1:8080;
 proxy_http_version 1.1;
 proxy_set_header Upgrade $http_upgrade;
 proxy_set_header Connection keep-alive;
 proxy_set_header Connection "Upgrade";
 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;

 #hsts header
 add_header Strict-Transport-Security "max-age=31536000" always;
 }
}

# Redirect unencrypted http access to encrypted https access.
server {
 listen 80 default_server;
 listen [::]:80 default_server ipv6only=on;

 server_name _;

 return 301 https://$host$request_uri;
}

Enable the configuration via symlink:

1. Disable the default configuration of nginx.

   sudo rm /etc/nginx/sites-enabled/default

2. Enable the configuration which you have created.

   sudo ln -s /etc/nginx/sites-available/codesys-4 /etc/nginx/sites-enabled/codesys-4

Now restart nginx to apply the changed configuration:

sudo systemctl restart nginx

Also set the nginx unit to enabled to also automatically start the reverse proxy at system startup:

sudo systemctl enable nginx

If you do not know your IP address, then run the ip command. The requirement for this is that your company network and firewall allow access.

ip addr

#1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
#    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
#    inet 127.0.0.1/8 scope host lo
#       valid_lft forever preferred_lft forever
#    inet6 ::1/128 scope host noprefixroute
#       valid_lft forever preferred_lft forever
#2: end0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
#    link/ether 01:23:45:67:89:ab brd ff:ff:ff:ff:ff:ff
#    inet 192.168.0.123/24 brd 192.168.0.255 scope global dynamic noprefixroute end0
#       valid_lft 350450sec preferred_lft 350450sec
#    inet6 fe80::0123:1234:2345:3456/64 scope link noprefixroute
#       valid_lft forever preferred_lft forever