Move files on remote system, only if destination d

Question

I'm trying to write an Ansible role that moves a number of files on the remote system. I found a Stack Overflow post about how to do this, which essentially says "just use the command module with 'mv'". I have a single task defined with a with_items statement like this where each item in dirs is a dictionary with src and dest keys:

- name: Move directories
  command: mv {{ item.src }} {{ item.dest }}
  with_items: dirs

This is good and it works, but I run into problems if the destination directory already exists. I don't want to overwrite it, so I thought about trying to stat each dest directory first. I wanted to update the dirs variable with the stat info, but as far as I know, there isn't a good way to set or update variables once they're defined. So I used stat to get the info on each directory and then saved the data with register:

- name: Check if directories already exist
  stat: path={{ item.dest }}
  with_items: dirs
  register: dirs_stat

Is there a way to tie the registered stat info to the mv commands? This would be easy if it were a single directory. The looping is what makes this tricky. Is there a way to do this without unrolling this loop into two tasks per directory?

Answer 1

This is not the simplest solution by any means, but if you wanted to use Ansible and not "unroll":

---
- hosts: all
  vars:
    dirs:
      - src: /home/ubuntu/src/test/src1
        dest: /home/ubuntu/src/test/dest1
      - src: /home/ubuntu/src/test/src2
        dest: /home/ubuntu/src/test/dest2
  tasks:
    - stat:
        path: "{{item.dest}}"
      with_items: dirs
      register: dirs_stat
    - debug:
        msg: "should not copy {{ item.0.src }}"
      with_together:
        - dirs
        - dirs_stat.results
      when: item.1.stat.exists

Simply adapt the debug task to run the appropriate command task instead and when: to when: not ....