How to make a variable available across multiple ansible playbooks? - ansible

Question

In my first playbook, I am asking user for a value and storing in a variable. I would like that variable to be accessible in other playbooks. There is only one host in the inventory btw.
My first playbook:
---
- name: Get the name of the city from the user
hosts: all
gather_facts: yes
vars_prompt:
- name: my_city
prompt: "Enter the name of city: "
private: no
tasks:
- name: Set fact for city
set_fact:
city: "{{ my_city }}"
cacheable: yes
In another playbook, when I try to print the variable I set in the previous one, I get an error:
---
- name: Print a fact
hosts: all
gather_facts: yes
tasks:
- name: Print ansible_facts['city'] variable
debug:
msg: "Value of city variable is {{ ansible_facts['city'] }}"
Error:
fatal: [testing]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'city'\n\nThe error appears to be in '/home/user/ansible_tasks/print_fact.yml': line 6, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n tasks:\n - name: Print ansible_facts['city'] variable\n ^ here\n"}

Answer 1

Enable the cache if you want to use it. For example,
shell> grep fact_caching ansible.cfg
fact_caching = jsonfile
fact_caching_connection = /tmp/ansible_cache
fact_caching_prefix = ansible_facts_
fact_caching_timeout = 86400
Then the playbook below
shell> cat pb1.yml
- hosts: localhost
gather_facts: false
tasks:
- set_fact:
city: my_city
cacheable: true
will store the variable city in the cache
shell> cat /tmp/ansible_cache/ansible_facts_localhost
{
"city": "my_city"
}
The next playbook
shell> cat pb2.yml
- hosts: localhost
gather_facts: false
tasks:
- debug:
var: city
will read the cache
shell> ansible-playbook pb2.yml
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
ok: [localhost] =>
city: my_city
PLAY RECAP ***********************************************************************************
localhost: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
If you want to cache the same variable in multiple hosts, for example
shell> cat hosts
host_1
host_2
host_3
it is sufficient to run the module set_fact once. The playbook
shell> cat pb3.yml
- hosts: all
gather_facts: false
tasks:
- set_fact:
city: my_city
cacheable: true
run_once: true
will store the variable city in the cache of all hosts
shell> grep -r city /tmp/ansible_cache/
/tmp/ansible_cache/ansible_facts_host_3: "city": "my_city"
/tmp/ansible_cache/ansible_facts_host_1: "city": "my_city"
/tmp/ansible_cache/ansible_facts_host_2: "city": "my_city"
The next playbook
shell> cat pb4.yml
- hosts: all
gather_facts: false
tasks:
- debug:
var: city
will read the cache
shell> ansible-playbook pb4.yml
PLAY [all] ***********************************************************************************
TASK [debug] *********************************************************************************
ok: [host_1] =>
city: my_city
ok: [host_2] =>
city: my_city
ok: [host_3] =>
city: my_city
PLAY RECAP ***********************************************************************************
host_1: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
host_2: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
host_3: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0