Plugins(feature): Add Optional Warning or Error to Defined test

[ClausHolbechArista]

Change Summary

Add Optional Warning or Error to Defined test

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Documentation content changes
• Other (please describe):

Related Issue(s)

Fixes #943 since that was caused by running the playbook for only a subset of devices.

Component(s) name

arista.avd.eos_designs
arista.avd.defined

Proposed changes

defined test

Optionally the test can emit warnings or errors if the test fails.

Syntax:

{% <value> is arista.avd.defined(test_value=<test_value>,fail_action=['warning','error'],var_name=<string representing name of value>) %}

Warnings or Errors can be emitted with the optional arguments fail_action and var_name:

{% if my_dict.my_list[12].my_var is arista.avd.defined(fail_action='warning', var_name='my_dict.my_list[12].my_var' %}
>>> [WARNING]: my_dict.my_list[12].my_var was expected but not set. Output may be incorrect or incomplete!

{% if my_dict.my_list[12].my_var is arista.avd.defined(fail_action='error', var_name='my_dict.my_list[12].my_var' %}
>>> fatal: [DC2-RS1]: FAILED! => {"msg": "my_dict.my_list[12].my_var was expected but not set!"}

{% set my_dict.my_list[12].my_var = 'not_my_value' %}

{% if my_dict.my_list[12].my_var is arista.avd.defined('my_value', fail_action='warning', var_name='my_dict.my_list[12].my_var' %}
>>> [WARNING]: my_dict.my_list[12].my_var was set to not_my_value but we expected my_value. Output may be incorrect or incomplete!

{% if my_dict.my_list[12].my_var is arista.avd.defined('my_value', fail_action='error', var_name='my_dict.my_list[12].my_var' %}
>>> fatal: [DC2-RS1]: FAILED! => {"msg": "my_dict.my_list[12].my_var was set to not_my_value but we expected my_value!"}

Added warnings to EVPN EBGP overlay.

Warn if switch facts are not set for a fabric device, since this can potentially result in incomplete or incorrect config.

How to test

By running a playbook with --limit for a device with overlay config will produce warnings.
Ex. for a two-dc scenario run the playbook for only one of the DCs.

Checklist:

• My code has been rebased from devel before I start
• I have read the CONTRIBUTING document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have updated molecule CI testing accordingly
• All new and existing tests passed (pre-commit, make linting and make sanity-lint).

[ClausHolbechArista]

@carlbuchmann CI passes now. Please review.

[carlbuchmann]

LGTM!