A ansible playbook to modify ulimit

modify_ulimit.yml

- hosts: all
  become: true
  tasks:
    - name: configure system settings, file descriptors and number of threads
      pam_limits:
        domain: <--your-username-->
        limit_type: "{{item.limit_type}}"
        limit_item: "{{item.limit_item}}"
        value: "{{item.value}}"
      with_items:
        - { limit_type: '-', limit_item: 'nofile', value: 65536 }
        - { limit_type: '-', limit_item: 'nproc', value: 65536 }
        - { limit_type: 'soft', limit_item: 'memlock', value: unlimited }
        - { limit_type: 'hard', limit_item: 'memlock', value: unlimited }
    - name: reload settings from all system configuration files
      shell: sysctl --system

Thanks again.
Is it compulsory to do sysctl --system?

I think yes, else you need to login again

Thanks for the nice write-up. one correction: sysctl --system is not related to config files under /etc/security/, it is more for sysctl conf files under /etc/sysctl.d/; /run/sysctl.d; etc