Sbt Packaging For Dummies
First of all I need some kind of disclaimer. Yes, I’ve started learning Scala and Akka Actors model, so that sometimes you will find the posts about scala here.
After I wrote my first hello world in Scala I asked myself how to get distributable package from the sources using SBT.
How to create a jar from my project?
Just type sbt package in cli inside your project folder. This command will create a single jar file, containing all your code.
Okay, how to get my dependencies too? You have two options: create fat-jar or create a package.
Create fat jar
Fat jar is very big jar-file containing compiled source code and all its dependencies in one file. Quite useful for one-time deployment, experiments and so on.
Add the following string into
# project/plugins.sbt
addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.12.0")
And configuration merging rules:
# build.sbt
mergeStrategy in assembly <<= (mergeStrategy in assembly) {
(old) => {
// discard META-INF
case PathList("META-INF", xs @ _*) => MergeStrategy.discard
// concat application.conf
case "application.conf" => MergeStrategy.concat
case "reference.conf" => MergeStrategy.concat
case x => MergeStrategy.first
}
}
Type sbt assembly in your project. You will get a very big jar file inside target folder.
Create a package
If you want something more distributable you can use sbt pack plugin. It will create a bunch of files ready for release.
Add the following string into
# project/plugins.sbt
addSbtPlugin("org.xerial.sbt" % "sbt-pack" % "0.7.9")
To use the plugin with default options just add the following string into build.sbt:
# build.sbt
packAutoSettings
Type sbt pack in your project. You will get a folder called pack inside your target folder. It will contain Makefile, binaries to start an app and all jars.
