[Feature]: Optional injects of metadata when rendering templates

[travisbcotton]

Describe the feature

The cloud-init client will inject info into the metadata from the host
Something like:

 "v1": {
  "_beta_keys": [
   "subplatform"
  ],
  "distro": "sles",
  "distro_release": "x86_64",
  "distro_version": "15.5",
  "instance-id": "i-9c239758",
  "instance_id": "i-9c239758",
  "machine": "x86_64",
  "platform": "nocloud",
  "public_ssh_keys": [],
  "python_version": "3.6.15",
  "variant": "suse"
 }

if I have a template like:

## template: jinja
#cloud-config
{% if v1.variant == 'suse' %}
{% set def_dir = '/foo' %}
{% else %}
{% set def_dir = '/bar' %}
{% endif %}
write_files:
  - content: |
       my stuff
     path: {{ def_dir }}/myfile
     permissions: '0644'
     owner: 'root:root'

The v1.variant is not stored in the metadata-service and so the render from the ochami CLI will never work.
I would like the ability to inject this kind of data on the CLI to get rendering to work, something like

ochami cloud-init group render --extra-vars='"v1.variant":"suse"' <template> <node>

Why do you want this feature?

This would help render templates where the variables are instantiated on boot and not a part of the metadata-service.

Alternatives you've considered

No response

Additional context

No response

Code of Conduct

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