How to Run Rails App Server with Systemd and Ansible

Create a systemd service to run your rails app server. 

Ansible tasks to create the service:

---
…snip…
vars:
rails_root: “/myapp”
rails_user: “webuser”
tasks:
- name: Setup Rails Web Service
template:
dest: /usr/lib/systemd/system/rails-web.service
src: templates/rails-web.systemd.j2
- name: Enable Rails Web Service
  systemd:
    name: rails-web
    daemon_reload: yes
    enabled: yes
    masked: no

The ansible template "rails-web.systemd.j2":

[Unit]
Description=Rails Web
[Service]
Type=simple
SyslogIdentifier=rails-web
User={{ rails_user }}
PIDFile={{ rails_root }}/tmp/pids/web.pid
WorkingDirectory={{ rails_root }}
ExecStart=/bin/bash -l -c “{{ rails_root }}/bin/rails s -b 0.0.0.0 -p 3000”
ExecReload=/bin/kill -s USR2 $MAINPID
ExecStop=/bin/kill -s QUIT $MAINPID
[Install]
WantedBy=multi-user.target

But you can also do this manually by creating the file `/usr/lib/systemd/system/rails-web.service` and then runninh `systemctl daemon-reload` to let systemd know about your service. Now you can start it up with systemctl start rails-web!