toallab-automation/roles/ansible-network.cisco_ios/docs/get_facts.md

Get facts from device

The get_facts function can be used to collect facts from an Cisco IOS devices. This function is only supported over network_cli connection type and requires the ansible_network_os value set to ios.

How to get facts from the device

To collect facts from the device, simply include this function in the playbook using either the roles directive or the tasks directive. If no other options are provided, then all of the available facts will be collected for the device.

Below is an example of how to use the roles directive to collect all facts from the IOS device.

- hosts: cisco_ios

  roles:
    - name ansible-network.cisco_ios
      function: get_facts

The above playbook will return the facts for the host under the cisco_ios top level key.

Filter the subset of facts returned

By default all available facts will be returned by the get_facts function. If you only want to return a subset of the facts, you can specify the subset variable as a list of keys to return.

For instance, the below will return only interfaces and system facts.

- hosts: cisco_ios

  roles:
    - name ansible-network.cisco_ios
      function: get_facts
      subset: 
        - system

Implement using tasks

The get_facts function can also be implemented using the tasks directive instead of the roles directive. By using the tasks directive, you can control when the fact collection is run.

Below is an example of how to use the get_facts function with tasks.

- hosts: cisco_ios

  tasks:
    - name: collect facts from cisco ios devices
      import_role:
        name: ansible-network.cisco_ios
        tasks_from: get_facts
      vars:
        subset:
          - system
          - interfaces

Adding new parsers

Over time new parsers can be added (or updated) to the role to add additional or enhanced functionality. To add or update parsers perform the following steps:

• Add (or update) command parser located ino parse_templates/cli

• Update the vars/get_facts_command_map.yaml file to map the CLI command to the parser

The get_facts_command_map.yaml file provides a mapping between CLI command and parser used to transform the output into Ansible facts.

Understanding the mapping file

The command map file provides the mapping between show command and parser file. The format of the file is a list of objects. Each object supports a set of keys that can be configured to provide granular control over how each command is implemented.

Command map entries support the following keys:

command

The command key is required and specifies the actual CLI command to execute on the target device. The output from the command is then passed to the parser for further processing.

parser

The parser key provides the name of the parser used to accept the output from the command. The parser value shoule be the command parser filename either relative to parser_templates/cli or absolute path. This value is required.

engine

This key accepts one of two values, either command_parser or textfsm_parser. This value instructs the the parsing function as to which parsing engine to use to parse the output from the CLI command.

This key is not required and, if not provided, the engine will assumed to be command_parser

groups

Commands can be contained in one (or more) groups to make it easy for playbook designers to filter specific facts to retreive from the network device. The groups key must be a list and contain the groups the this command should be associated with.

pre_hook

The pre_hook key provides the path to the set of tasks to include prior to running the command on the CLI. This is useful if there is a need to check if a command is available or supported on a particular version.

post_hook

The post_hook key provides the path to the set of tasks to include after the command has been run on the target device and its results have been parsed by the parser.

Arguments

ios_get_facts_subset

Defines the subset of facts to collection when the get_facts function is called. This value must be a list value and contain only the sub keys for the facts you wish to return.

The default value is default

Aliases

• subset

Current supported values for subset are

• default
• all
• interfaces
• bgp
• lldp

ios_get_facts_command_map

Defines the command / parser mapping file to use when the call to get_facts is made by the playbook. Normally this value does not need to be modified but can be used to pass a custom command map to the function.

The default value is vars/get_facts_command_map.yaml

Notes

None