Systemd ignores any PATH settings = you need to use full path to rvm. In order to use puma under RVM with systemd you need to create a wrapper for RVM:

cd /root/myapp
rvm current                                   # e.g.: ruby-3.2.2@myapp_2023

# create RVM wrapper
rvm alias create myapp ruby-3.2.2@myapp_2023  # rybyversion@gemsetname

Depending where is your RVM instaled (check with which rvm) this creates a wrapper in RVM folder. Mine is /usr/share/rvm/wrappers/myapp . This you can refer in systemd service file. (RVM wrapper is something similar to aias or symbolic link)

# /etc/systemd/system/myapp_puma.service

[Unit]
Description=Puma HTTP Server
After=network.target

# Uncomment for socket activation (see below)
# Requires=puma.socket

[Service]
Type=notify

WatchdogSec=10

# Preferably configure a non-privileged user
# User=

WorkingDirectory=/root/myapp_tw

# Explicitly define your ENV variables as they may be ignored
Environment=WEB_CONCURRENCY=3
Environment=RAILS_ENV=production

# Helpful for debugging socket activation, etc.
# Environment=PUMA_DEBUG=1

ExecStart=/usr/share/rvm/wrappers/myapp/bundle exec puma -C ./config/puma.rb

Restart=always

[Install]
WantedBy=multi-user.target

note: I ln -s my master.key to app config/master.key so I don’t use RAILS_MASTER_KER

systemctl daemon-reload              #each  time you change the service file
systemctl start myapp_puma.service
systemctl status myapp_puma.service

# something goes wrong
journalctl -u myapp_puma -e -f

Note: any time you change ruby version or gemset you need to recreate the RVM wrapper

source:

Rails 7.1, Ruby 3.2, Puma 6, RVM rvm 1.29.12, Ubuntu 22.04. Created 2023-11-30

keywords: init.d, system.d, puma webserver, ruby on rails, rvm