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inframan
Asked: 2022-10-18 01:58:21 +0800 CST

How to handle existing/non existing fact in Ansible?

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For inventory purpose due to some business limitation, i wrote a playbook that retrieve content of resolv.conf + ntp.conf + timesyncd.conf and then, write the retrieved content within a CSV file.

Globally, maybe it's not the best practice but i set a fact at every task for retrieving file content, then i format the datas as i would and finally, write them in a csv like data1;data2;data3;

I got some issues/questions there :

  • if the file doesn't exists,Ansible task fails and doesn't go to the next task, i know this is by design. To prevent that, should it be a good solution to use failed_when/changed_when conditionals near retrieving tasks ?
  • in the last task ("Write results to ...") how to handle non-existing fact ? at the moment if 3 facts are existing, file is written. If 1/3 facts doesn't exists but others are , nothing is written. Thanks a lot for your advices. Playbook is below
---

- name: sys-check_conf_ntp_dns_net
  hosts: my_servers
  remote_user: my_user

  tasks:
    # RESOLV.CONF
    - name: Retrieve remote /etc/resolv.conf 
      ansible.builtin.slurp:
        src: /etc/resolv.conf
      register: resolv_conf

    - name: Format resolv_conf_fact data
      set_fact:
        resolv_conf_fact: "{{ (resolv_conf['content'] | b64decode) | regex_findall('\\s*nameserver\\s*(.*)') }}"

    # NTP.CONF
    - name: Retrieve remote /etc/ntp.conf 
      ansible.builtin.slurp:
        src: /etc/ntp.conf
      register: ntp_conf

    - name: Format ntp_conf_fact data
      set_fact:
        ntp_conf_fact: "{{ (ntp_conf['content'] | b64decode) | regex_findall('(\\nserver.*?)(\\n)') }}"

    # TIMESYNCD.CONF
    - name: Retrieve /etc/systemd/timesyncd.conf 
      ansible.builtin.slurp:
        src: /etc/systemd/timesyncd.conf
      register: timesyncd_conf

    - name: Format timesyncd_conf_fact data
      set_fact:
        timesyncd_conf_fact: "{{ (timesyncd_conf['content'] | b64decode) | regex_search('(NTP=f.*)') }}"

    - name: Write results to /tmp/sys-check_conf_ntp_dns_net.csv
      lineinfile:
        path: /tmp/sys-check_conf_ntp_dns_net.csv
        line: "Hostname:{{inventory_hostname}};resolv.conf:{{ resolv_conf_fact }};ntp.conf:{{ ntp_conf_fact }};timesyncd.conf:{{ timesyncd_conf_fact }};"
        create: yes
      delegate_to: localhost

EDIT

I finally found a workaround, not sure if it's legal or not :D For every fact i set, i add a default value, then as it's filtered through the regex, it behaves like the fact is not empty and so seems to work at the end.

For example :

Setting a fact before :

ntp_conf_fact: "{{ (ntp_conf['content'] | b64decode) | regex_findall('(\\nserver.*?)(\\n)') }}"

Setting a fact after :

ntp_conf_fact: "{{ ((ntp_conf['content']|default([blabla])) | b64decode) | regex_findall('(\\nserver.*?)(\\n)') }}"

Can someone confirm if it sounds ok ? or if anyone got a different solution ?

ansible

0 Answers