systemd

systemd is the default init system on most Linux distributions. systemd is kinda like going to high school - no one ever has a good time with it, but it sure as hell beats not having it.

Services

Create and edit services the easy way

systemctl provides a fun and interactive way to edit services with your $EDITOR. Use the systemctl edit command to never have to think about where to place service files, timers, mounts or whatever systemd comes up with ever again.

# override the default service file with specific custom instructions
sudo systemctl edit <service>

# edit the default service file
sudo systemctl edit --full <service>

# create a new service file and edit it
sudo systemctl edit --full --force <new-service>

Using systemd to automatically restart Puma server on boot

View this GitHub link for more details on achieving this.

If you are using RVM or rbenv, don't forget to add the necessary environment variables.

# Substitute {username}, {application} and {ruby_version} to get your
# full service file
# e.g. (in Vi): %s/{ruby_version}/2.6.3/g

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

[Service]
# Background process configuration (use with --daemon in ExecStart)
Type=forking

# Preferably configure a non-privileged user
User={username}

# The path to the puma application root
WorkingDirectory=/srv/{application}/current

# The command to start Puma
ExecStart=/srv/{application}/current/bin/bundle exec puma -C /srv/{application}/shared/puma.rb --daemon

# The command to stop Puma
ExecStop=/srv/{application}/current/bin/bundle exec pumactl -S /srv/{application}/shared/tmp/pids/puma.state stop

# Should systemd restart puma?
Restart=on-failure

# `puma_ctl restart` wouldn't work without this.
# See the original config file for details.
RemainAfterExit=yes

# Include these environment variables if you are using RVM - don't forget
# to update with proper paths depending on your Ruby version!
Environment=GEM_HOME=/srv/{application}/.rvm/gems/ruby-{ruby_version}
Environment=PATH=/srv/{application}/.rvm/gems/ruby{ruby_version}/bin:/srv/{application}/.rvm/gems/ruby-{ruby_version}@global/bin:/srv/{application}/.rvm/rubies/ruby-{ruby_version}/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin:/srv/{application}/.rvm/bin

# Choose one or the other (rvm or rbenv) - using both will muck it up.

# Include these environment variables if you are using rbenv - no need to
# specify the proper version because rbenv is magic!
Environment=RBENV_ROOT=/srv/{application}/.rbenv
Environment=PATH=/srv/{application}/.rbenv/shims:/srv/{application}/.rbenv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin

[Install]
WantedBy=multi-user.target