What is the proper way to use openapi-generator for generating ktor server stubs

Question

When trying to generate server-side stubs for ktor from openapi, the output to me does not really look very usable.

I set up an example project on Github, where the setup can be reviewed. As I need to use maven in my real project, I used it here as well but I guess this should not make a difference to other generation methods.

The relevant part of the POM is this:

<build>
    ...

    <plugins>
        ...

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-resources-plugin</artifactId>
            <version>2.6</version>
            <executions>
                <execution>
                    <id>resources</id>
                    <phase>compile</phase>
                    <goals><goal>copy-resources</goal></goals>
                    <configuration>
                        <outputDirectory>${project.build.directory}/classes</outputDirectory>
                        <resources>
                            <resource>
                                <directory>${project.basedir}/resources</directory>
                            </resource>
                        </resources>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

What will be generated is the following:

• Data Model
• A Paths.kt object containing the paths to my routes in ktor-locations format
• An example stub implementing the API as an extension function of io.ktor.routing.Route
• A complete application, including configs, Dockerfile, Gradle Files, etc.

Coming from SpringBoot and Swagger, I am a bit confused, as this set of files is not really useful if you want to create an actual application implementing real business logic. I would have expected some default implementation holding single methods that I just need to implement / override. I realize that ktor has no DI built in, so I would also expect to have to extend the routing stub in my application somehow.

However, with this set of generated code, I can really only use the data model and the Paths.kt object. I will have my own application and the default implementation I can not override but need to rewrite completely myself.

So my question is, how to set up a proper ktor application implementing openapi specifications. Do I miss anything or do I really only get the model and Paths.kt to work with?

Edit

For more clarity: especially with these parts of my application I am not happy to have no support from the tooling:

fun Application.module(testing: Boolean = false) {
    // other setup

    routing {
        // some other interfaces I may have

        FooApiImpl()
    }
}

/**
 * This Api Implementation has to be written completely manually. No help from the generated Code...
 */
@KtorExperimentalLocationsAPI
fun Route.FooApiImpl() {
    get<Paths.getAllFoos> {
        call.respond(listOf(
            Foo( id = -1, bar = "hello"),
            Foo( id = -2, bar = "world")
        ))
    }

    // the path gets named after the first method, which is weird in my eyes.
    post<Paths.getAllFoos> {
        val foo = call.receive<Foo>()
        // fooService.save(foo)
        call.respond(foo)
    }

    delete<Paths.deleteFooById> { path ->
        val id = path.id
        // fooService.deleteById(id)
        call.respond(HttpStatusCode.NoContent)
    }
}

Woodcock