FR: Update workflows to skip steps, fail conditions, set next step manually

[nembery]

Current implementation only allows a list of skillets to execute in order. This FR should at least do the following:

1. allow a skillet to be skipped
2. allow a skillet output to exit the workflow with a defined message to the user
3. allow setting the next_step based on some logic

[nembery]

Example: snippets:

• name: get_system_info when: "{% 'true' if sw_version is not defined else 'false' %}"
• name: load_iron_skillet_v80 when: "{% 'true' if sw_version == '8.0' else 'false' %}"
• name: load_iron_skillet_v81 when: "{% 'true' if sw_version == '8.1' else 'false' %}"
• name: load_iron_skillet_v90 when: "{% 'true' if sw_version == '9.0' else 'false' %}"

[nembery]

Example of when to fail with fail_message: snippets:

• name: get_system_info when: "{% 'true' if sw_version is not defined else 'false' %}"
• name: get_policy_objects when: "{% 'true' if model == 'vm-50' else 'false' %}" fail_when: "{% 'true' if length(policy_objects) > 3 else 'false' %}" fail_message: Too many policy objects exist for this
• name: some_other_skillet

This example will run get_system_info only if it hasn't been run before. We know that because sw_version is a variable that will be captured when it's run. If it is not defined, then run this again so we know all the device facts.

Next run 'get_policy_objects' if the model == vm-50. Once run, count the output to see if we have more than 3 policy objects already and if so, fail with the fail_message

finally, run some_other_skillet. Note that if we do not have a vm-50, then the second skillet will be skipped and we can go directly to the last step

[nembery]

Also, Ansible has a very nice concept where they only take the conditional from the yaml and automatically wrap it in the 'if' 'else', 'endif' stuff. Example here: https://github.com/ansible/ansible/blob/421d67f1ee6e03d9768c5ab966ed3ee8fa3e36df/lib/ansible/playbook/conditional.py#L192

We should look at this and see if we can just wrap the conditional, or if we should also do the additional checks as well for various safety reasons...

[nembery]

example in that case would just be something like: snippets:

• name: get_system_info when: sw_version is not defined instead of the long form of: "{% 'true' if sw_version is not defined else 'false' %}"