title: Configuring application using application.yaml instead of application.properties
body: <p>I have a small Quarkus <code>1.1.0.Final</code> Web application (using Java <code>1.8</code>). I'm trying to use a YAML file to configure the application (instead of the usual <code>application.properties</code>) but there is no way the application comes up. I'm always getting this not-so-useful error message(s):</p>
  
  <pre class="lang-sh prettyprint-override"><code>13:53:32,494 ERROR [io.qua.dev.DevModeMain] Failed to start Quarkus: java.lang.RuntimeException: io.quarkus.builder.ChainBuildException: No producers for required item class io.quarkus.deployment.builditem.BuildTimeRunTimeFixedConfigurationBuildItem
      at io.quarkus.runner.RuntimeRunner.run(RuntimeRunner.java:180)
      at io.quarkus.dev.DevModeMain.doStart(DevModeMain.java:177)
      at io.quarkus.dev.DevModeMain.start(DevModeMain.java:95)
      at io.quarkus.dev.DevModeMain.main(DevModeMain.java:66)
  Caused by: io.quarkus.builder.ChainBuildException: No producers for required item class io.quarkus.deployment.builditem.BuildTimeRunTimeFixedConfigurationBuildItem
      at io.quarkus.builder.BuildChainBuilder.build(BuildChainBuilder.java:240)
      at io.quarkus.deployment.QuarkusAugmentor.run(QuarkusAugmentor.java:112)
      at io.quarkus.runner.RuntimeRunner.run(RuntimeRunner.java:113)
      ... 3 more
  
  13:53:32,519 INFO  [io.qua.dev.DevModeMain] Attempting to start hot replacement endpoint to recover from previous Quarkus startup failure
  13:53:32,532 ERROR [io.qua.dev.DevModeMain] Failed to start quarkus: java.lang.IllegalArgumentException: workerPoolSize must be &gt; 0
      at io.vertx.core.VertxOptions.setWorkerPoolSize(VertxOptions.java:275)
      at io.quarkus.vertx.core.runtime.VertxCoreRecorder.convertToVertxOptions(VertxCoreRecorder.java:151)
      at io.quarkus.vertx.core.runtime.VertxCoreRecorder.initializeWeb(VertxCoreRecorder.java:104)
      at io.quarkus.vertx.http.runtime.VertxHttpRecorder.startServerAfterFailedStart(VertxHttpRecorder.java:115)
      at io.quarkus.vertx.http.deployment.devmode.VertxHotReplacementSetup.handleFailedInitialStart(VertxHotReplacementSetup.java:30)
      at io.quarkus.dev.RuntimeUpdatesProcessor.startupFailed(RuntimeUpdatesProcessor.java:449)
      at io.quarkus.dev.DevModeMain.doStart(DevModeMain.java:191)
      at io.quarkus.dev.DevModeMain.start(DevModeMain.java:95)
      at io.quarkus.dev.DevModeMain.main(DevModeMain.java:66)
  </code></pre>
  
  <p>This is my YAML file:</p>
  
  <pre><code>#
  # https://quarkus.io/guides/all-config
  # https://quarkus.io/guides/config#overriding-properties-at-runtime
  quarkus:
    datasource:
      driver: org.postgresql.Driver
    flyway:
      migrate-at-start: true
    health:
      extensions:
        enabled: true
    hibernate-orm:
      dialect: org.hibernate.dialect.PostgreSQL10Dialect
    http:
      port: 8080
    log: # ALL &gt; FINEST &gt; FINER &gt; FINE &gt; CONFIG &gt; INFO &gt; WARNING &gt; SEVERE &gt; OFF
      console:
        async: true
        color: true
        enable: true
        format: "%d{yyyy-MM-dd HH:mm:ss,SSS} |- %-5p in %c:%L{3.} [%t] - %s%e%n"
      level: WARNING
    resteasy:
      path: /api
    smallrye-openapi:
      path: /open-api
    swagger-ui:
      always-include: true
      path: /swagger-ui
  
  "%dev":
    quarkus:
      datasource:
        password: postgres
        url: jdbc:postgresql://localhost:5432/quarkus_web
        username: postgres
      flyway:
        clean-at-start: true
      hibernate-orm:
        log:
          sql: true
        statistics: true
      log:
        category:
          "io.quarkus.arc.processor":
            level: OFF
          "io.quarkus":
            level: INFO
          "org.acme":
            level: CONFIG
  
  "%prod":
    quarkus:
      datasource:
        password: postgres
        url: jdbc:postgresql://localhost:5432/quarkus_web
        username: postgres
      flyway:
        clean-at-start: false
      hibernate-orm:
        database:
          generation: none
        sql-load-script: no-file
  
  "%test":
    quarkus:
      datasource:
        password: postgres
        url: jdbc:postgresql://localhost:5432/quarkus_web
        username: postgres
      flyway:
        clean-at-start: true
      log:
        category:
          "io.quarkus":
            level: WARNING
          "org.acme":
            level: WARNING
  </code></pre>
  
  <p>Anyone using this approach already and succeeded? I'm including <code>io.quarkus:quarkus-config-yaml:1.1.0.Final</code>.</p>
  
  <blockquote>
    <p>One thing that I've noticed is that I can't separate the profiles using <code>---</code> as I do with Spring Boot. I think I should file an issue for this :thinking_face:</p>
  </blockquote>