using pm2 with ansible

Question

I am trying to start a node program using pm2 via ansible. The problem is that the pm2 start command is not idempotent under ansible. It gives error when run again.

This is my ansible play

- name: start the application
  become_user: ubuntu
  command: pm2 start app.js -i max
  tags: 
    - app

Now if i run this the first time then it runs properly but when i run this again then i get the error telling me that the script is already running.

What would be the correct way to get around this error and handle pm2 properly via ansible.

Answer 1

Before starting the script you should delete previous, like this:

 - name: delete existing pm2 processes if running
   command: "pm2 delete {{ server_id }}"
   ignore_errors: True
   become: yes
   become_user: rw_user


 - name: start pm2 process
   command: 'pm2 start -x -i 4 --name "{{server_id}}" server.js'
   become: yes
   become_user: rw_user
   environment:
    NODE_ENV: "{{server_env}}"