014 Inventory cache
Extending example 010 Clone basejails and create inventory.
Use case
Enable and test inventory cache.
Tree
shell> tree .
.
├── ansible.cfg
├── iocage.yml
├── pb-cache-dump.yml
└── pb-vars-ip4.yml
Synopsis
At a managed node:
get the dynamic inventory by the inventory plugin vbotka.freebsd.iocage
configure and test
cache
Requirements
ansible.cfg
[defaults]
gathering = explicit
callback_result_format = yaml
display_skipped_hosts = false
[connection]
pipelining = true
Inventory iocage.yml
Enable cache
plugin: vbotka.freebsd.iocage
host: 10.1.0.73
user: admin
env:
CRYPTOGRAPHY_OPENSSL_NO_LEGACY: 1
get_properties: False
cache: True
cache_plugin: ansible.builtin.jsonfile
cache_connection: /var/tmp/inventory_cache
cache_timeout: 3600
cache_prefix: iocage_
strict: True
compose:
ansible_host: iocage_ip4
release: iocage_release | split('-') | first
release_major: iocage_release | split('-') | first | split('.') | first
release_minor: iocage_release | split('-') | first | split('.') | last
groups:
test: inventory_hostname.startswith('test')
keyed_groups:
- prefix: distro
key: iocage_release
- prefix: state
key: iocage_state
Hint
If you do not configure cache_plugin, Ansible falls back to caching inventory with the fact
cache plugin you configured. For example,
shell> grep fact_caching ansible.cfg
fact_caching = ansible.builtin.jsonfile
fact_caching_connection = /var/tmp/ansible_cache
fact_caching_timeout = 3600
fact_caching_prefix = ''
Playbook pb-vars-ip4.yml
pb-vars-ip4.yml
- hosts: all
tasks:
- debug:
var: iocage_ip4
Playbook output - Clear cache
In this particular case, it takes 4s to create the dynamic inventory and construct the variables
after the cache was cleared (flushed).
(env) > date +%r; \
ANSIBLE_STDOUT_CALLBACK=community.general.timestamp \
ansible-playbook pb-vars-ip4.yml -i iocage.yml -l test_113 --flush-cache
23:03:34
PLAY [all] ************************************************************ 23:03:37
TASK [debug] ********************************************************** 23:03:37
ok: [test_113] =>
iocage_ip4: 10.1.0.113
PLAY RECAP ************************************************************ 23:03:37
test_113 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
Playbook output - Cache enabled
If the cache is enabled, the inventory and variables are provided by the cache immediately
(env) > date +%r; \
ANSIBLE_STDOUT_CALLBACK=community.general.timestamp \
ansible-playbook pb-vars-ip4.yml -i iocage.yml -l test_113
23:03:37
PLAY [all] ************************************************************ 23:03:38
TASK [debug] ********************************************************** 23:03:38
ok: [test_113] =>
iocage_ip4: 10.1.0.113
PLAY RECAP ************************************************************ 23:03:38
test_113 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
Hint
Use the option –flush-cache to clear the cache.
Cache
Look at the cache. For example,
shell> cat /var/tmp/inventory_cache/iocage_vbotka.freebsd.iocage_a5393s_956f5
{
"_meta": {
"hostvars": {
"ansible_client": {
"iocage_basejail": "yes",
"iocage_boot": "off",
"iocage_ip4": "10.1.0.199",
"iocage_ip4_dict": {
"ip4": [
{
"ifc": "em0",
"ip": "10.1.0.199",
"mask": "24"
}
],
"msg": ""
},
"iocage_ip6": "-",
"iocage_jid": "None",
"iocage_release": "14.2-RELEASE-p3",
"iocage_state": "down",
"iocage_template": "-",
"iocage_type": "jail"
},
"test_111": {
"iocage_basejail": "yes",
"iocage_boot": "off",
"iocage_ip4": "10.1.0.111",
"iocage_ip4_dict": {
"ip4": [
{
"ifc": "em0",
"ip": "10.1.0.111",
"mask": "24"
}
],
"msg": ""
},
"iocage_ip6": "-",
"iocage_jid": "None",
"iocage_release": "14.2-RELEASE-p3",
"iocage_state": "down",
"iocage_template": "ansible_client",
"iocage_type": "jail"
},
"test_112": {
"iocage_basejail": "yes",
"iocage_boot": "off",
"iocage_ip4": "10.1.0.112",
"iocage_ip4_dict": {
"ip4": [
{
"ifc": "em0",
"ip": "10.1.0.112",
"mask": "24"
}
],
"msg": ""
},
"iocage_ip6": "-",
"iocage_jid": "None",
"iocage_release": "14.2-RELEASE-p3",
"iocage_state": "down",
"iocage_template": "ansible_client",
"iocage_type": "jail"
},
"test_113": {
"iocage_basejail": "yes",
"iocage_boot": "off",
"iocage_ip4": "10.1.0.113",
"iocage_ip4_dict": {
"ip4": [
{
"ifc": "em0",
"ip": "10.1.0.113",
"mask": "24"
}
],
"msg": ""
},
"iocage_ip6": "-",
"iocage_jid": "None",
"iocage_release": "14.2-RELEASE-p3",
"iocage_state": "down",
"iocage_template": "ansible_client",
"iocage_type": "jail"
}
}
}
}
The cache format has changed since Ansible 2.19. Use the below playbook to read the cache
pb-cache-dump.yml
- name: Dump cache.
hosts: localhost
vars:
cache: "{{ lookup('file', cache_file) | from_yaml }}"
tasks:
- assert:
that: cache_file is defined
fail_msg: "[ERR] variable cache_file is not defined."
quiet: true
- debug:
var: cache.__payload__ | from_yaml
For example,
shell> ansible-playbook pb-cache-dump.yml \
-e cache_file=/var/tmp/inventory_cache/iocage_04_s1_vbotka.freebsd.iocage_kfb2392
PLAY [Dump cache.] *************************************************************
TASK [assert] ******************************************************************
ok: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] =>
cache.__payload__ | from_yaml:
_meta:
hostvars:
test_4:
iocage_basejail: 'no'
iocage_boot: 'off'
iocage_hooks:
- '-'
iocage_ip4: '-'
iocage_ip4_dict:
ip4: []
msg: '-'
iocage_ip6: '-'
iocage_jid: None
iocage_properties:
CONFIG_VERSION: '33'
...