Questions about file copy / modification

[Sacha Lrt]

Hello everybody ! 

I'm kind of new around here and a fresh new Ansible user ! So my questions may sounds little bit stupid...

Anyway ! My environment is the following : I'm using ansible to manage VM behind a bastion. So I have a ssh.cfg file with ProxyCommand in it etc.

Everything is working but this is slow ! And this is actually normal. 

Still, I was wondering how exactly copy / unarchive / file modules are proceeding.

Let's assume that I have a httpd.conf file deployed on my VM. Everytime I'm running my playbook with the copy module with a httpd.conf file as src parameter, what is going to happen ?

Is Ansible going to check if modifications have been done ? Or is Ansible simply replacing the file ?

I'm asking these questions because when I run my playbook, I get the "ok" status for the copy task but couldn't find anything about it ! I really want to make sure that ansible isn't doing anything that could slow down my general deployment.

Indeed, I want to know what is better in term of speed : 

- Use the copy module directly 

OR 

- add a WHEN condition to the copy task and have a rapid checksum using stat module before running the copy ?

Basically, my general question is : 

What is actually doing copy / file (symlink use case) /  unarchive modules whereas the version on the remote server is the same as the local one !

My goal is to avoid any useless operations in order to minimize the time of my playbook run.

So that I have an answer to this question : Is it worth using different stat module in order to determine if I should run a task or not ?

As an example, is it better to perform this :

- name: Checking if the link has to be updated

  stat: 

   path: "{{ ihm_symlink_name }}"

  register: ihm_lnk_stat

- name: Update the {{ name }} symlink to point at the new folder

  file:

   src: "{{ folder_path }}"

   dest: "{{ symlink_name }}"

   state: link

  when: ihm_lnk_stat.stat.lnk_target != "{{ folder_path }}"

OR simply that : 

- name: Update the {{ name }} symlink to point at the new folder

  file:

   src: "{{ folder_path }}"

   dest: "{{ symlink_name }}"

   state: link

I hope you see what I mean and why I'm asking me this question ! If not, please tell me, I'll try to rephrase !

Thank you for reading me !