Force Ansible to gather facts from group - postgresql

Question

I want to force Ansible to gather facts about hosts inside playbook (to use those data inside role) regardless --limit, but don't know how.
I have playbook like this:
- hosts: postgres_access
tasks:
- name: Gathering info
action: setup
- hosts: postgres
roles:
- postgres
Inside 'postgres' role I have template which iterates over default IPs:
{% for host in groups['postgres_access'] %}
host all all {{hostvars[host].ansible_default_ipv4.address}}/32 md5
{% endfor %}
This works like magic, but only if I run my playbook without --limit. If I use --limit it breaks, because some hosts in hostgroup have no gathered facts.
ansible-playbook -i testing db.yml --limit postgres
failed: [pgtest] (item=pg_hba.conf) => {"failed": true, "item": "pg_hba.conf", "msg": "AnsibleUndefinedVariable: 'dict object' has no attribute 'ansible_default_ipv4'"}
How can I have --limit to reconfigure only postgres host, and have network data from other hosts (without doing all other configuration stuff?).

Answer 1

Try this please !
- hosts: postgres
pre_tasks:
- setup:
delegate_to: "{{item}}"
with_items: "{{groups['postgres_access']}}"
roles:
- postgres

Answer 2

You can run setup for the hosts in the postgres_access group as a task and save the facts using register:
- name: setup hosts
action: "setup {{ item }} filter=ansible_default_ipv4"
with_items: groups.postgres_access
register: ip_v4
- name: create template
template: src=[your template] dest=[your dest file]
Just keep in mind that the template needs to change how you are referencing the hosts ipv4 address, I tried with something like this:
{% for item in ip_v4.results %}
host all all {{ item.ansible_facts.ansible_default_ipv4.address }}/32 md5
{% endfor %}
For printing just the IP of each host in the group

Answer 3

Try this:
- hosts: postgres
pre_tasks:
- setup:
delegate_to: postgres_access
roles:
- postgres

Answer 4

Use the same role which you have defined as it is with ignore_errors: true . So that for hosts which do not have gathered data will not fail.
And if you want data to be gathered for all the hosts in both groups postgres_access and postgres, then add gather_facts: true to get facts for postgres group and for postgres_access you already have a task written.
- hosts: postgres_access
tasks:
- name: Gathering info
action: setup
- hosts: postgres
gather_facts: true
roles:
- postgres
ignore_errors: true