Check if arrays are defined and not empty in ansible

Question

I have the following code

- set_fact:     MY_HOSTNAME: "SOME VALUE"     MY_SERVER: "00.00.00.00" - name: Get MY server   set_fact:     MY_SERVER: "{{ groups[MY_HOSTNAME][0] }}"   when: groups[MY_HOSTNAME] is defined 

In the above code, groups[MY_HOSTNAME] is an array. What is the best way to check that groups[MY_HOSTNAME] is defined and also that it is not empty If it is either of that I want the value 00.00.00.00 to be assigned to MY_SERVER

Answer 1

I don't know if it's version specific, but I'm currently running ansible-2.3.2 on RHEL6 and I had to put quotes around the group name to get it to work for me:

when: groups["GROUP_NAME"] is defined and (groups["GROUP_NAME"]|length>0) 

Edit: I couldn't add this as a comment to techraf's answer because I don't have enough reputation.