Install and configure systemd on Cloud Server

This guide explains how to install and configure systemd on one Cloud Server and presents the main usable orders.

Prerequisites

• Follow installation guidesystemd for Cloud Server.
• Consult official documentation to learn about all the possibilities offered by systemd
• Unit files should be placed in: ~/.config/systemd/user/ ( /home/clients/absolute-path-id/.config/systemd/user ) (replaced) absolute-path-id in your Manager) and permissions must be paid in 0644.
• The parameter --user shall be indicated in each order.

Main orders

Here is a non-exhaustive list of commands usable with systemd.

Force systemd to read again the units files and to take into account the modifications:

systemctl --user daemon-reload

Activation of a service:

systemctl --user enable --now SERVICENAME.service

Checking the status of a service:

systemctl --user status SERVICENAME.service

Configuring Node as a Service with Systemd

It will be necessary to create a "Unit" file with the ".service" extension, which will need to be saved in the directory:

~/.config/systemd/user/

The following example can be reused by replacing the values starting with {}:

[Unit]
Description={Le nom du service} # Spécifier ici un nom du service. Celui-ci est obligatoire mais n'a pas d'impact sur le fonctionnement

[Service]
Restart=always
Environment=NODE_VERSION={la version souhaitée} # Spécifier ici la version de Node à utiliser. S'assurer qu'elle soit installée au préalable avec "nvm install {la version souhaitée}"
WorkingDirectory=%h/{repertoire du projet Node} # %h correspond à la racine de l'hébergement
ExecStart=/bin/bash -c "exec $HOME/.nvm/nvm-exec {commande de lancement du script node}" # Cette commande dépend du projet. Par exemple, "npm run start", "npm run serve" ou encore "node server.js" sont courants

[Install]
WantedBy=default.target

Additional actions with a Unit file

systemctl --user daemon-reload

Start the service (if it is already active, nothing happens):

systemctl --user start [Nom du Unit]

Stop the service (if it is not active, nothing happens):

systemctl --user stop [Nom du Unit]

Restart service (if it does not turn, it is launched):

systemctl --user restart [Nom du Unit]

Obtain information on the service; in particular:

• "Active" which indicates whether the service is running and since when
• "CGroup" shows the process group that the service manages, allowing to see the active processes, with their arguments and ID

Below "CGroup" are possible logs (standard output and process error):

systemctl --user status [Nom du Unit]

Enable automatic booting of service to server boot; NB: it does not start service:

systemctl --user enable [Nom du Unit]

Disable automatic booting of service to server boot; NB: it does not stop service:

systemctl --user disable [Nom du Unit]

Configuration with user inputs:

[Unit]
Description="nom service"

[Service]
Restart=always
Environment=NODE_VERSION=16.17
WorkingDirectory=%h/sites/"nom-repertoire-site"/
ExecStart=/bin/bash -c "exec $HOME/.nvm/nvm-exec npm run start"

[Install]
WantedBy=default.target