014 Inventory cache

Extending example 010.

Use case

Enable and test inventory cache.

Tree

shell> tree .
.
├── ansible.cfg
├── iocage.yml
└── pb-vars-ip4.yml

Requirements

Configuration ansible.cfg

[defaults]
gathering = explicit
callback_result_format = yaml

[connection]
pipelining = true

Inventory iocage.yml

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

Playbook pb-vars-ip4.yml

- hosts: all

  tasks:

    - debug:
        var: iocage_ip4

Playbook output

It takes 4s in this case to create the dynamic inventory and construct the variables.
(The cache is disabled in iocage.yml. cache=False)
(env) > date +%r; \
        ANSIBLE_STDOUT_CALLBACK=community.general.timestamp \
	ansible-playbook pb-vars-ip4.yml \
	                 -i iocage.yml \
	                 -l test_113

13:49:31

PLAY [all] ************************************************************ 13:49:35

TASK [debug] ********************************************************** 13:49:35
ok: [test_113] => {
    "iocage_ip4": "10.1.0.113"
}

PLAY RECAP ************************************************************ 13:49:35
test_113: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

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 output

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

13:55:40

PLAY [all] ************************************************************ 13:55:41

TASK [debug] ********************************************************** 13:55:41
ok: [test_113] => {
    "iocage_ip4": "10.1.0.113"
}

PLAY RECAP ************************************************************ 13:55:41
test_113: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Cache

Take a look at the cache

shell> cat /var/tmp/inventory_cache/iocage_vbotka.freebsd.iocage_a5393s_6a9dd
{
    "_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": "14.1-RELEASE-p6",
                "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": "14.1-RELEASE-p6",
                "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": "14.1-RELEASE-p6",
                "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": "60",
                "iocage_release": "14.1-RELEASE-p6",
                "iocage_state": "up",
                "iocage_template": "ansible_client",
                "iocage_type": "jail"
            }
        }
    }
}