A Hello World for a simple REST API in VertX and Kotlin.

To launch tests:

./mvnw clean test

To package:

./mvnw clean package

To run:

./mvnw clean compile exec:java

Features:

• Simple validation and error handling
• Example operations for common HTTP operations in plain Vertx
• Example operations for common HTTP operations with OpenAPI
  • Also includes Swagger UI ready to try out the operations
• Example file-based Basic Auth implementation with role validation
• Nice Kotlin data class handling
• Nice encapsulation of REST functionality and business logic
• Unit tests to test the exposed REST APIs
• Config handling for bootstrapping and during execution
• Major version of artifact is included in REST paths

ToDo:

• Proper asynchronous request handling via coroutines
• Maybe add a third way where OpenAPI documentation is created on the fly by annotations in the code
• Dependency Injection (maybe, quite a hassle)
• in-memory DB with nice persistence - this is a whole project on itself though
• Version setting does not work in the openapi.yaml file, maybe we should switch to https://www.mojohaus.org/build-helper-maven-plugin/parse-version-mojo.html

Remarks:

• OpenAPI provides these features:
  • Routes and operations are defined and validated
  • Defining security (sadly roles are not supported by OpenAPI 3.0 for Basic Auth)
  • Schema validation of body parameters, query and path params
  • Validation of MIME types (however implementation does not return error code 415 if no handler accepts the request mime type but rather returns 400 - did not bother creating a bug for that yet)
• Swagger UI is available on localhost:$MainVerticle.PORT/swagger/swagger-ui
• Role validation for basic auth is done horribly manually, I wonder if there is a nicer way
• To get the current config, see ConfigHandler.kt
• The major version in the REST path is set by the Maven Resources Plugin so check the pom.xml <resources> tag for details