Appending additional files to the fat JAR

[eed3si9n]

There should be easier way to append to assembledMappings.
If there is one, document it.

[medale]

+1. assembledMappings is listed as one of the keys for the assembly task on the README.md but googling for it I only found older examples that did not compile in sbt 0.13.13. Any current examples? I am trying to add an application.conf file that was generated by the sbt editsource plugin (http://software.clapper.org/sbt-editsource/) to my fat jar. Any pointers in much appreciated!

[medale]

Example:
I was using the EditSource plugin to templatize version, project name (based on directory) and buildDate using the following settings where the template file is in module/templates/application.conf for each subproject (I had other template files and in this plugin only one targetDirectory can be specified - I did not want to put all the template output files in the fat jar):

lazy val editSourcePluginSettings = Seq(
  compile in Compile := ((compile in Compile) dependsOn (edit in EditSource)).value,
  flatten in EditSource := true,
  //use <module>/templates/application.conf
  sources in EditSource := Seq(
    baseDirectory.value / "templates/application.conf"
  ),
  targetDirectory in EditSource := baseDirectory.value / "target",
  variables in EditSource ++= Seq(
    ("version", version.value),
    ("projectDirName", baseDirectory.value.name),
    ("buildDate", dateFormat.format(new java.util.Date()))
  )
)

This put my application.conf under module/target/application.conf. I then used the following assembledMappings to get that application.conf into the root of my fat jar:

lazy val assemblyPluginSettings = Seq(  
...
  assembledMappings in assembly += {
    sbtassembly.MappingSet(None, Vector(
      (baseDirectory.value / "target" / "application.conf") -> "application.conf"
    ))
  }
...
)

In this case the file did not come from a jar file so the first argument in MappingSet is None, otherwise Some(new File(jarFilePath))? I have not tried that out but according to the MappingSet comments in AssemblyKeys.scala:

...
// Keep track of the source package of mappings that come from a jar, so we can
// sha1 the jar instead of the unpacked packages when determining whether to rebuild
case class MappingSet(sourcePackage : Option[File], mappings : Vector[(File, String)]) {
...