[Console] Update format of services.yaml

[mikaylathompson]

Description

The services.yaml file is the core location for information about the current deployment and making the implementation clean and easy to validate will be helpful moving forward.

There were a few recent comments regarding the file format in the reviews of the e2e branch merge & the OSI backfill additions:

• ensure that the yaml file itself, and the README about it use spaces rather than tabs: Merge E2E branch into main #690 (comment)
• write yaml structure with mutually-exclusive "nodes": [Console] OSI support for API and Console Library #680 (comment)

For the second point, the idea is to move AWAY from:

source_cluster:
  authorization:
    type: basic_auth
    details:
      user: abc
      password: xyz

And towards:

source_cluster:
  basic_auth:
    username: abc
    password: xyz

In general, instead of having a type field, each service description should instead have a node with the name of the type that contains any relevant details. The schema validation can then be written to ensure that no mutually-exclusive nodes are present.

Notes on Approach

The bulk of this PR is updating documentation and tests--the actual schemas involved are quite small still (hence doing this refactoring now).

There was no built-in Cerberus rule to validate that exactly one block of a selection was present. I created a generator that returns a callable to verify that exactly one key from a given list is provided. I think this should be quite widely used throughout our schemas. I also think that this PR makes the schemas a bit more modularized and readable.

Issues Resolved

https://opensearch.atlassian.net/browse/MIGRATIONS-1754

Testing

Unit tests, manual

Check List

• New functionality includes testing
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov]

Codecov Report

Attention: Patch coverage is 97.29730% with 1 line in your changes missing coverage. Please review.

Project coverage is 62.96%. Comparing base (16c735b) to head (b1dc04f).
Report is 1 commits behind head on main.

Files	Patch %	Lines
...console_link/console_link/models/metrics_source.py	93.33%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #718      +/-   ##
============================================
- Coverage     63.29%   62.96%   -0.33%     
  Complexity     1579     1579              
============================================
  Files           220      231      +11     
  Lines          9156     9729     +573     
  Branches        793      793              
============================================
+ Hits           5795     6126     +331     
- Misses         2950     3195     +245     
+ Partials        411      408       -3     

Flag	Coverage Δ
unittests	63.31% <ø> (+0.02%)	⬆️

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[lewijacn]

Thanks!

[lewijacn]

nit: Do you have a link you can comment for what schema options like "nullable" are available for a schema

[mikaylathompson]

Yes! https://docs.python-cerberus.org/validation-rules.html