Dockerizing Scala Application

build.sbt

// No need to run tests while building jar
test in assembly := {}
// Simple and constant jar name
assemblyJarName in assembly := s"app-assembly.jar"
// Merge strategy for assembling conflicts
assemblyMergeStrategy in assembly := {
  case PathList("reference.conf") => MergeStrategy.concat
  case PathList("META-INF", "MANIFEST.MF") => MergeStrategy.discard
  case _ => MergeStrategy.first
}

Dockerfile

FROM openjdk:8-jre-alpine

RUN mkdir -p /opt/app
WORKDIR /opt/app

COPY ./run_jar.sh ./app-assembly.jar ./

ENTRYPOINT ["./run_jar.sh"]

plugins.sbt

// sbt-assembly for "fat jars"
addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.5")

run_jar.sh

#!/usr/bin/env sh

java $* -jar app-assembly.jar