factgathering

Fact Gathering for z/OS

The zos_gather_facts module expands on Ansible's built in fact gathering to provide various facts to the Ansible playbook author.

Run the sample playbook

ansible-playbook -i <inventory> gather-facts.yml

The provided gather-facts.yml playbook runs the zos fact gathering module zos_gather_facts several times with different subsets and filter settings to demonstrate the available parameters.

• First zos_gather_facts is called with the ipl gather_subset and a filter set to master*. This matches 2 available facts both of which are printed in the following step through the built in debug module. That next step shows how collected facts can be accessed in the context of a playbook by calling on the ansible_facts variable.
• Then the zos_gather_facts module is called with two gather_subsets specified cpu and iodf and once more the built in debug module is called to print out collected facts. The print step shows an alternate way to access those facts.
• The final step in the playbook prints out all the collected facts which have been added to the ansible_facts variable.

Caching facts

Collected facts can be cached into a database and accessed later without taking a performance hit from repeatedly running fact gathering.

How to enable local JSON caching

To set up caching into a local json file, 2 variables have to be configured. These can be configured in an ansible.cfg file, as regular environment variables, or in the command line where the playbook is called.

In ansible.cfg, set values for:

[inventory]
cache_plugin=jsonfile
fact_caching_connection=<some_folder_location>

As environment variables:

• export ANSIBLE_INVENTORY_CACHE_PLUGIN=jsonfile
• export ANSIBLE_CACHE_PLUGIN_CONNECTION='<some_folder_location>'

In the command line, set values for:

• ANSIBLE_CACHE_PLUGIN=jsonfile
• ANSIBLE_CACHE_PLUGIN_CONNECTION='<some_folder_location>'

Example command to run playbook and output ansible_facts to a local json file. ansible_facts is the variable in which the playbook stores various gathered facts. It is also where any facts gathered by default through the builtin Ansible fact gathering are stored.

ANSIBLE_CACHE_PLUGIN=jsonfile ANSIBLE_CACHE_PLUGIN_CONNECTION='<some_folder_location>' ansible-playbook -i inventories gather-facts.yml

Additional resources for Ansible caching

Caching ansible_facts is achieved through Ansible cache plugins. There are a number of cache plugins provided by Ansible and a custom cache plugin can also be specified. The documentation for calling upon cache plugins can be found here.

Some plugins implemented in Ansible:

• json - here
• redis - here
• mongo - here

The full list of cache plugins can be found by following the steps in the section here.

Changelog

All changes are maintained chronologically by date found in the changelog.

Copyright

© Copyright IBM Corporation 2023

License

Licensed under Apache License, Version 2.0.

Support

Please refer to the support section for more details.