feat(nebula_ros): add json schema

[amadeuszsz]

PR Type

• New Feature

Related Links

• Issue: Parameters: align with Autoware Foundation proposal for ROS nodes #63
• Schema discussion: https://github.com/orgs/autowarefoundation/discussions/3371
• Schema docs: https://autowarefoundation.github.io/autoware-documentation/main/contributing/coding-guidelines/ros-nodes/parameters/
• CI PR: ci(json-schema-check): allow nested config paths autowarefoundation/autoware-github-actions#294

Description

The PR adds json schema to nebula which is current way of handling param files in Autoware environment. The proposed changes consider schema composition based on few abstractions:

The contains of specific abstraction may still change. The schema for now brings two drawbacks:

• Due to our abstraction, we can't use additionalProperties=false. Sub schemas are pushed to the same parent key ros__parameters, therefore they would block itself in case of not allowing extra parameters. With additionalProperties=true, users can provide extra parameters to '.param.yaml' but at the end they not affect runtime.
• Schema considers only two numeric types: number and integer. Therefore for floating point number and type of number, the user can provide integer value as well. This will throw exception in node constructor. From schema level, we can't force user to use floating point number. We could provide extra method for declaring floating point number instead of declare_parameter. The idea would be to load parameter with dynamic typing, check the type, cast it to double and set it again.

Review Procedure

1. Install json-schema

pip install check-jsonschema

2. Copy CI script locally, e.g. to package root.
3. Test nebula param files.

cd <nebula-root>
python validate_json_schemas.py

4. Test VS Code extension.

• Install YAML extension (redhat.vscode-yaml).
• Update your .vscode/settings.json, e.g.:

    "yaml.schemas": {
        "src/vendor/nebula/nebula_ros/schema/VLP16.schema.json": "lidar/velodyne/VLP16.param.yaml"
    }

• Check if works.
  

Remarks

• Since this PR is made on top of one development branch, please wait for refactor(velodyne)!: combine Velodyne ROS wrappers into a single node #148 merged.
• The CI requires merge in external repository first. If PR will be rejected, we might add CI script into nebula package.

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• Commits are properly organized and messages are according to the guideline
• (Optional) Unit tests have been written for new behavior
• PR title describes the changes

Post-Review Checklist for the PR Author

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• All open points are addressed and tracked via issues or tickets

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• Build and test for PR: Required to pass before the merge.