Description

This PR overhauls our Docker image's method of injecting configuration values into Swagger UI.

Broadly, it solves the following problems:

• Many configuration variables were not exposed through the old method
• Our old method of injection was not idempotent - multiple runs of the image could break things
• Our sed approach of editing things on the fly was difficult to test

It introduces the following new environment variables:

• CONFIG_URL
• DEEP_LINKING
• DEFAULT_MODEL_EXPAND_DEPTH
• DEFAULT_MODEL_RENDERING
• DEFAULT_MODELS_EXPAND_DEPTH
• DISPLAY_OPERATION_ID
• DISPLAY_REQUEST_DURATION
• DOC_EXPANSION
• DOM_ID
• FILTER
• LAYOUT
• MAX_DISPLAYED_TAGS
• OAUTH2_REDIRECT_URL
• SHOW_COMMON_EXTENSIONS
• SHOW_EXTENSIONS
• SHOW_MUTATED_REQUEST
• SPEC
• SUPPORTED_SUBMIT_METHODS
• URL
• URLS_PRIMARY_NAME
• URLS
• VALIDATOR_URL

It deprecates the following existing environment variables, which will continue to work until v4.0:

• API_URL
• API_URLS

Motivation and Context

• Fixes Providing configuration via Docker #3902
• Fixes Feature request: ability to set oauth2RedirectUrl using env vars in Docker #3138
• Resolves Multiple files to SWAGGER_JSON #4820

How Has This Been Tested?

I added unit tests for the config object generator, and manually tested functionality with a local Docker image.

Screenshots (if appropriate):

Checklist

My PR contains...

• No code changes (src/ is unmodified: changes to documentation, CI, metadata, etc.)
• Dependency changes (any modification to dependencies in package.json)
• Bug fixes (non-breaking change which fixes an issue)
• Improvements (misc. changes to existing features)
• Features (non-breaking change which adds functionality)

My changes...

• are breaking changes to a public API (config options, System API, major UI change, etc).
• are breaking changes to a private API (Redux, component props, utility functions, etc.).
• are breaking changes to a developer API (npm script behavior changes, new dev system dependencies, etc).
• are not breaking changes.

Documentation

• My changes do not require a change to the project documentation.
• My changes require a change to the project documentation.
• If yes to above: I have updated the documentation accordingly.

Automated tests

• My changes can not or do not need to be tested.
• My changes can and should be tested by unit and/or integration tests.
• If yes to above: I have added tests to cover my changes.
• If yes to above: I have taken care to cover edge cases in my tests.
• All new and existing tests passed.