Generate resources for compile and test

Question

I intend to generate resources based on templates and sbt settings. There should be different sbt settings for Compile and Test. The templates are in project/resources/hdfs/*.xml. From the sbt-dev gitter chat, I've had the recommendation to use Setting and inConfig, but I couldn't get it to work.

Code so far:

val hdfsNamenode = settingKey[String]("Namenode for the HDFS access")

def genHdfsConfigs: Setting[_] =
  hdfsNamenode := {
    resourceGenerators += Def.task {
      val files = ((baseDirectory.value / "project" / "resources" / "hdfs" ) * "*.xml").get
      files.foreach({ hdfsTemplate =>
        val config = IO.read(hdfsTemplate).replace("{{namenode}}", hdfsNamenode.value)
        IO.write(resourceManaged.value / hdfsTemplate.getName, config)
      })
      files.toSeq
    }.taskValue
  }

hdfsNamenode in Test := "localhost"
hdfsNamenode in Compile := "172.31.32.228"

def allHdfsNamenodeConfigs: Seq[Setting[_]] =
  inConfig(Compile)(Seq(hdfsNamenode)) ++ inConfig(Test)(Seq(hdfsNamenode))

Errors:

[error]  found   : sbt.Def.Setting[Seq[sbt.Task[Seq[java.io.File]]]]
[error]  required: String
[error]       resourceGenerators += Def.task {
[error]                          ^

[error]  found   : sbt.SettingKey[String]
[error]  required: sbt.Def.Setting[_]
[error]     inConfig(Compile)(Seq(hdfsNamenode)) ++ inConfig(Test)(Seq(hdfsNamenode))
[error]        

Next iteration, I don't know how to get the hdfsNameNode in scope Compile/Test instead of unscoped.

lazy val hdfsNameNode = settingKey[String]("Namenode for the HDFS access")

val genHdfsConfig = Def.task {
  val files = ((baseDirectory.value / "project" / "templates" / "resources" / "hdfs" ) * "*.xml").get
  files.map({ hdfsTemplate =>
    val config = IO.read(hdfsTemplate).replace("{{namenode}}", hdfsNameNode.value)
    val outputPath = resourceManaged.value / hdfsTemplate.getName
    IO.write(outputPath, config)
    outputPath
  })
}

Seq(
    hdfsNameNode := "undefined", // Only this one is accepted
    hdfsNameNode in Test := "localhost",
    hdfsNameNode in Compile := "172.31.32.228",
    resourceGenerators in Compile += genHdfsConfig.taskValue,
    resourceGenerators in Test += genHdfsConfig.taskValue
  )

Current (ugly) solution:

val hdfsTestNameNode = "localhost"
val hdfsMainNameNode = "172.31.32.228"

val hdfsNameNode = settingKey[String]("Namenode for the HDFS access")

val genTestHdfsConfig = Def.task {
  val files = ((baseDirectory.value / "project" / "templates" / "resources" / "hdfs" ) * "*.xml").get
  files.map({ hdfsTemplate =>
    val config = IO.read(hdfsTemplate).replace("{{namenode}}", (hdfsNameNode in Test).value)
    val outputPath = resourceManaged.value / hdfsTemplate.getName
    IO.write(outputPath, config)
    outputPath
  })
}

val genCompileHdfsConfig = Def.task {
  val files = ((baseDirectory.value / "project" / "templates" / "resources" / "hdfs" ) * "*.xml").get
  files.map({ hdfsTemplate =>
    val config = IO.read(hdfsTemplate).replace("{{namenode}}", (hdfsNameNode in Compile).value)
    val outputPath = resourceManaged.value / hdfsTemplate.getName
    IO.write(outputPath, config)
    outputPath
  })
}

Seq(
  hdfsNameNode in Test := hdfsTestNameNode,
  hdfsNameNode in Compile := hdfsMainNameNode,
  resourceGenerators in Compile += genCompileHdfsConfig.taskValue,
  resourceGenerators in Test += genTestHdfsConfig.taskValue
 )

Answer 1

Just pass the Configuration as an argument when you define your resource generator.

val hdfsTestNameNode = "localhost"
val hdfsMainNameNode = "172.31.32.228"

val hdfsNameNode = settingKey[String]("Namenode for the HDFS access")

def genHdfsConfig(cfg: Configuration) = Def.task {
  val files = ((baseDirectory.value / "project" / "templates" / "resources" / "hdfs" ) * "*.xml").get
  files.map({ hdfsTemplate =>
    val config = IO.read(hdfsTemplate).replace("{{namenode}}", (hdfsNameNode in cfg).value)
    val outputPath = (resourceManaged in cfg).value / hdfsTemplate.getName
    IO.write(outputPath, config)
    outputPath
  })
}

Seq(
  hdfsNameNode in Test := hdfsTestNameNode,
  hdfsNameNode in Compile := hdfsMainNameNode,
  resourceGenerators in Compile += genHdfsConfig(Compile).taskValue,
  resourceGenerators in Test += genHdfsConfig(Test).taskValue
)

Don't want to specify the scope twice? Just refactor a bit more.

val hdfsTestNameNode = "localhost"
val hdfsMainNameNode = "172.31.32.228"

val hdfsNameNode = settingKey[String]("Namenode for the HDFS access")

def addHdfsConfigGenerator(cfg: Configuration) = {
  inConfig(cfg) {
    val hdfsConfigGenerator = Def.task {
      val files = ((baseDirectory.value / "project" / "templates" / "resources" / "hdfs" ) * "*.xml").get
      files.map({ hdfsTemplate =>
        val config = IO.read(hdfsTemplate).replace("{{namenode}}", (hdfsNameNode in cfg).value)
        val outputPath = (resourceManaged in cfg).value / hdfsTemplate.getName
        IO.write(outputPath, config)
        outputPath
      })
    }
    resourceGenerators += hdfsConfigGenerator.taskValue
  } last
}

Seq(
  hdfsNameNode in Test := hdfsTestNameNode,
  hdfsNameNode in Compile := hdfsMainNameNode,
  addHdfsConfigGenerator(Compile),
  addHdfsConfigGenerator(Test)
)