Set fact with dynamic key name in ansible
Solution 1
take a look at this sample playbook:
---
- hosts: localhost
vars:
iter:
- key: abc
val: xyz
- key: efg
val: uvw
tasks:
- set_fact: {"{{ item.key }}":"{{ item.val }}"}
with_items: "{{iter}}"
- debug: msg="key={{item.key}}, hostvar={{hostvars['localhost'][item.key]}}"
with_items: "{{iter}}"
Solution 2
The above does not work for me. What finally works is
- set_fact:
example_dict: "{'{{ some var }}':'{{ some other var }}'}"
Which is in the end obvious. You construct a string (the outer double quotes) which is then interpreted as a hash. In hashes key and value must be single quotes (the inner single quotes around the variable replacements). And finally you just place your variable replacements as in any other string.
Stefan
Solution 3
As of 2018, using ansible v2.7.1, the syntax you suggest in your post works perfectly well.
At least in my case, I have this in role "a" :
- name: Set fact
set_fact:
"{{ variable_name }}": "{{ variable_value }}"
And that in role "b" :
- debug:
msg: "variable_name = {{ variable_name }}"
And execution goes :
TASK [role a : Set fact] *******************************************************
ok: [host_name] => {
"ansible_facts": {
"variable_name": "actual value"
},
"changed": false
}
...
TASK [role b : debug] **********************************************************
ok: [host_name] => {}
MSG:
variable_name = actual value
Solution 4
- set_fact: '{{ some_var }}={{ some_value }}'
It creates a string of inline module parameter expression by concatenating value of some_var
(fact name), separator =
and value of some_value
(fact value).
Solution 5
- set_fact:
var1={"{{variable_name}}":"{{ some value }}"}
This will create a variable "var1" with your dynamic variable key and value.
Example: I used this for creating dynamic tags in AWS Autoscaling group for creating kubernetes tags for the instances like this:
- name: Dynamic clustertag set_fact: clustertag={"kubernetes.io/cluster/{{ clustername }}":"owned"}
- name: Create the auto scale group
ec2_asg:
.
.
.
tags:
- "{{ clustertag }}"
Nick Roz
Ruby on Rails & Java Script programmer. Used to work as 1C programmer. Also love music, 3d modeling, painting, reading, watching TV, playing computer games, cooking. Curious.
Updated on May 26, 2020Comments
-
Nick Roz about 4 years
I am trying to shrink several chunks of similar code which looks like:
- ... multiple things is going here register: list_register - name: Generating list set_fact: my_list="{{ list_register.results | map(attribute='ansible_facts.list_item') | list }}" # the same code repeats...
In fact, the only difference between them is that I am using different list names here instead of
my_list
In fact I want to do this:
set_fact: "{{ some var }}" : "{{ some value }}"
I came across this post but didn't find any answer here.
Is it possible to do so or is there any workaround?