I have a multi module SBT project that I’m using to build a Docker image out of. There is one module that depends on all the other modules and I’m actually trying to build the Docker image for this module. Here is a snippet from my build.sbt

lazy val impute = (project in file(MODULE_NAME_IMPUTE)).dependsOn(core% "compile->compile;test->test", config)
  .settings(
    commonSettings,
    enablingCoverageSettings,
    name := MODULE_NAME_IMPUTE,
    description := "Impute the training data"
  )
  .enablePlugins(JavaAppPackaging, DockerPlugin)

lazy val split = (project in file(MODULE_NAME_SPLIT)).dependsOn(core% "compile->compile;test->test", config)
  .settings(
    commonSettings,
    enablingCoverageSettings,
    dockerSettings("split"),
    name := MODULE_NAME_SPLIT,
    description := "Split the dataset into train and test"
  )
  .enablePlugins(JavaAppPackaging, DockerPlugin)

lazy val run = (project in file(MODULE_NAME_RUN)).dependsOn(core % "compile->compile;test->test", config, cleanse, encode, feature, impute, split)
  .settings(
    commonSettings,
    dockerSettings("run"),
    enablingCoverageSettings,
    name := MODULE_NAME_RUN,
    description := "To run the whole setup as a pipeline locally"
  )
  .enablePlugins(JavaAppPackaging, DockerPlugin)

As you can see, the run module depends on all the other modules and I’m actually trying to build the Docker image for the run module for which I used the following command:

sbt run/docker:publishLocal

This works fine and the Docker image is also built, but when I inspect my Docker image, especially on the ENTRYPOINT, I get to see the following:

        "Entrypoint": [
            "/opt/docker/bin/run"
        ],

But instead, I would have expected to see something like this:

        "Entrypoint": [
            "java",
            "-cp",
            "com.mypackage.housingml.run.Main"
        ],

Is there anything else that I’m missing? Here is my dockerSettings() function from my build.sbt:

def dockerSettings(name: String) = {
  Seq(
    // Always use latest tag
    dockerUpdateLatest := true,

    maintainer  := s"$projectMaintainer",

    // https://hub.docker.com/r/adoptopenjdk/openjdk13
    // Remember to use AshScriptPlugin if you are using an alpine based image
    dockerBaseImage := "adoptopenjdk/openjdk13:alpine-slim",

    // If you want to publish to a remote docker repository, uncomment the following:
    //dockerRepository := Some("remote-docker-hostname"),
    Docker / packageName := s"joesan/$projectName-$name",

    // If we're running in a docker container, then export logging volume.
    Docker / defaultLinuxLogsLocation := "/opt/docker/logs",
    dockerExposedVolumes := Seq((Docker / defaultLinuxLogsLocation).value),
    dockerEnvVars := Map(
      "LOG_DIR" -> (Docker / defaultLinuxLogsLocation).value,
    )
  )
}