deploy-node.yaml

---
- name: install node and npm
  hosts: ec2 
  become: yes # become root, don't use root for security best practices, package installation needs root user
  tasks:
    - name: update yum 
      yum: update_cache=yes

    - name: install nodejs and npm
      yum: # yum module
        name: 
          - nodejs
          - npm
        state: present

- name: Create new linux user for node app
  hosts: ec2
  become: yes # to create new user you need to be root
  vars_files: 
    - project-vars.yaml
  tasks:
    - name: Create Linux user
      user: # user module to create a new user
        name: "{{user_name}}"
        comment: created user is the admin 
        group: root
      register: user_creation_result   # variable registering 
    - debug: msg={{user_creation_result.uid}} # geting the user id of ram 


- name: Deploy nodejs app
  hosts: ec2 
  become: True  # to become a specific user 
  become_user: "{{user_name}}"
  vars_files:   # passing variables using variable file
    - project-vars.yaml
  vars:
    - location: /Users/ramraju/Desktop/Ansible/nodeapp.tgz  # passing variables directly

  tasks:
    - name : copy nodeapp.tgz folder to the server and unpack tar file
      unarchive: # unarchive module
        src: "{{location}}" # variable for nodefile location
        dest: "{{destination}}"  # home dir of user ram 
     

    - name: install dependencies
      npm: # npm module
        path: "{{destination}}/node-app/"

    - name: start the application
      command: #command module is more secure than shell module
        chdir: "{{destination}}/node-app/app"
        cmd: node server
      async:  1000  # async module to run the node command in background
      poll: 0

    - name: check if application is running
      shell: ps aux | grep node 
      register:  app_status # result of the above shell command will be assigned to the variable app_status
    - debug: msg={{app_status.stdout_lines}}         # reference the app_status variable to check the status of the node app