config: Parse model from JSON

[pellared]

Implement https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/configuration/file-configuration.md#parse for JSON.

[pellared]

PTAL @codeboten

[pellared]

Changing the description to update the documentation instead of adding a new function.

CC @carrbs @codeboten

[carrbs]

Was this ticket initially opened to address this?
https://github.com/open-telemetry/oteps/blob/main/text/0225-configuration.md?plain=1#L52-L61

---

In order to provide a minimal API surface area, implementations MUST support the following:

Parse(file) -> config

An API called Parse receives a file object. The method loads the contents of the file, parses it, and validates that the configuration against the schema. At least one of JSON or YAML MUST be supported. If either format can be supported without additional dependencies, that format SHOULD be preferred. If neither or both formats are supported natively, YAML should be the preferred choice. If YAML is not supported due to dependency concerns, there MAY be a way for a user to explicitly enable it by installing their own dependency.

The method returns a Configuration model that has been validated. This API MAY return an error or raise an exception, whichever is idiomatic to the implementation for the following reasons:

• file doesn't exist or is invalid
• configuration parsed is invalid according to schema

[pellared]

@carrbs Good finding 👍

Actually it should implement this: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/configuration/file-configuration.md#parse

Take notice that the specification currently requires only supporting YAML. Making as blocker per spec.

I updated the description.

[codeboten]

Take notice that the specification currently requires only supporting YAML. Making as blocker per spec.

The specification mentions both JSON or YAML. Are you saying that since only one is required and YAML is preferred if nether/both are supported, then we should only implement YAML parsing? Just trying to clarify what blocked on specification means here

[pellared]

TODO: decide if JSON file format is required

[codeboten]

@pellared ah fair... i missed this, as it goes against what's written further down :D

[pellared]

Closing the issue for now. We can reopen it if needed.