local_action: shell error concatenate files

Question

There is such an error in my playbook. Why and how to fix it? (getting the list of updates of remote-hosts, concatenate lists into one file)

- name: Save upd         


        

Answer 1

You use a glob ~/tmp/* and one of the files is ~/tmp/list_update, so effectively you order it to read and write to the same file with a redirection and system is refusing to do that.

You also didn't specify run_once, so the merge files from different hosts in once task will run as there are hosts defined for the play.

If you are sure ~/tmp/list_update didn't exist beforehand, adding run_once: true to that task would resolve the problem, but it's far from the best way.

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Long story short, you can achieve what you want in one task, for example

• with a Jinja2 template:

  - copy:
      content: "{% for host in ansible_play_hosts %}{{ hostvars[host].update_deb_packs.stdout }}\n{% endfor %}"
      dest: ~/tmp/list_update
    delegate_to: localhost
    run_once: true
  

  You can add separators with host-value to indicate what data is coming from which host:

  content: "{% for host in ansible_play_hosts %}From host: {{ host }}\n{{ hostvars[host].update_deb_packs.stdout }}\n{% endfor %}"
  

• using operations on lists:

  content: "{{ ansible_play_hosts | map('extract', hostvars, 'update_deb_packs') | map(attribute='stdout') | list }}"