DotEnvConfigSource.kt

import io.github.cdimascio.dotenv.dotenv
import org.eclipse.microprofile.config.spi.ConfigSource

/**
 * A bridge from https://github.com/cdimascio/java-dotenv to Quarkus/MicroProfile Config. Should only be used in test code, as these configs should be 
 * provided to lambda via env vars in prod.
 *
 * @see <a href="https://quarkus.io/guides/config#custom-configuration">Custom Config Source Quarkus Docs</a>
 * Note the service file at test/resources/META-INF/SERVICES/org.eclipse.microprofile.config.spi.ConfigSource
 */
class DotEnvConfigSource : ConfigSource {

    private val config = dotenv().entries()
            .map { toJavaStyleKey(it.key) to it.value }
            .toMap()

    override fun getName() : String {
        return "DotEnv"
    }

    override fun getValue(javaStyleKey: String) : String? {
        return config[javaStyleKey]
    }

    // priority is below application.properties
    override fun getOrdinal(): Int {
        return 100
    }

    override fun getProperties() : Map<String,String> = config

    private fun toJavaStyleKey(envStyleKey: String) = envStyleKey.replace('_','.').toLowerCase()
}