kolla-ansible/ansible/gather-facts.yml
Mark Goddard ade5bfa302 Use ansible_facts to reference facts
By default, Ansible injects a variable for every fact, prefixed with
ansible_. This can result in a large number of variables for each host,
which at scale can incur a performance penalty. Ansible provides a
configuration option [0] that can be set to False to prevent this
injection of facts. In this case, facts should be referenced via
ansible_facts.<fact>.

This change updates all references to Ansible facts within Kolla Ansible
from using individual fact variables to using the items in the
ansible_facts dictionary. This allows users to disable fact variable
injection in their Ansible configuration, which may provide some
performance improvement.

This change disables fact variable injection in the ansible
configuration used in CI, to catch any attempts to use the injected
variables.

[0] https://docs.ansible.com/ansible/latest/reference_appendices/config.html#inject-facts-as-vars

Change-Id: I7e9d5c9b8b9164d4aee3abb4e37c8f28d98ff5d1
Partially-Implements: blueprint performance-improvements
2021-06-23 10:38:06 +01:00

42 lines
1.6 KiB
YAML

---
# NOTE(awiddersheim): Gather facts for all hosts as a
# first step since several plays below require them when
# building their configurations.
- name: Gather facts for all hosts
hosts: all
serial: '{{ kolla_serial|default("0") }}'
gather_facts: true
tasks:
- name: Group hosts to determine when using --limit
group_by:
key: "all_using_limit_{{ (ansible_play_batch | length) != (groups['all'] | length) }}"
changed_when: false
tags: always
# NOTE(pbourke): This case covers deploying subsets of hosts using --limit. The
# limit arg will cause the first play to gather facts only about that node,
# meaning facts such as IP addresses for rabbitmq nodes etc. will be undefined
# in the case of adding a single compute node.
# NOTE(mgoddard): Divide all hosts to be queried between the hosts selected via
# the limit.
- name: Gather facts for all hosts (if using --limit)
hosts: all_using_limit_True
serial: '{{ kolla_serial|default("0") }}'
gather_facts: false
vars:
batch_index: "{{ ansible_play_batch.index(inventory_hostname) }}"
batch_size: "{{ ansible_play_batch | length }}"
# Use a python list slice to divide the group up.
# Syntax: [<start index>:<end index>:<step size>]
delegate_hosts: "{{ groups['all'][batch_index | int::batch_size | int] }}"
tasks:
- name: Gather facts
setup:
delegate_facts: True
delegate_to: "{{ item }}"
with_items: "{{ delegate_hosts }}"
# We gathered facts for all hosts in the batch during the first play.
when:
- not hostvars[item].ansible_facts.module_setup | default(false)
tags: always