How to package an akka project for a netlogo extension? - scala

Question

I am trying to make a simple NetLogo extension that is based on akka.
However, whenever I try to load the extension in NetLogo, I get the error:
Caused by: com.typesafe.config.ConfigException$Missing: No configuration setting found for key 'akka.version'
Which obviously means that some configuration is missing. I then proceded to add reference.conf to my resources folder but with no luck.
The last thing I tried was to use the sbt-assemblty plugin, but I keep getting the same error. So this is my build.sbt:
name := "TestAkka"
version := "1.0"
scalaVersion := "2.11.7"
scalaSource in Compile <<= baseDirectory(_ / "src")
scalacOptions ++= Seq("-deprecation", "-unchecked", "-Xfatal-warnings",
"-encoding", "us-ascii")
libraryDependencies ++= Seq(
"org.nlogo" % "NetLogo" % "5.3.0" from
"http://ccl.northwestern.edu/devel/NetLogo-5.3-17964bb.jar",
"asm" % "asm-all" % "3.3.1",
"org.picocontainer" % "picocontainer" % "2.13.6",
"com.typesafe" % "config" % "1.3.0",
"com.typesafe.akka" %% "akka-actor" % "2.4.1",
"com.typesafe.akka" %% "akka-remote" % "2.4.1"
)
artifactName := { (_, _, _) => "sample-scala.jar" }
packageOptions := Seq(
Package.ManifestAttributes(
("Extension-Name", "sample-scala"),
("Class-Manager", "main.scala.akkatest.TestClassManager"),
("NetLogo-Extension-API-Version", "5.3")))
packageBin in Compile <<= (packageBin in Compile, baseDirectory, streams) map {
(jar, base, s) =>
IO.copyFile(jar, base / "sample-scala.jar")
Process("pack200 --modification-time=latest --effort=9 --strip-debug " +
"--no-keep-file-order --unknown-attribute=strip " +
"sample-scala.jar.pack.gz sample-scala.jar").!!
if(Process("git diff --quiet --exit-code HEAD").! == 0) {
Process("git archive -o sample-scala.zip --prefix=sample-scala/ HEAD").!!
IO.createDirectory(base / "sample-scala")
IO.copyFile(base / "sample-scala.jar", base / "sample-scala" / "sample-scala.jar")
IO.copyFile(base / "sample-scala.jar.pack.gz", base / "sample-scala" / "sample-scala.jar.pack.gz")
Process("zip sample-scala.zip sample-scala/sample-scala.jar sample-scala/sample-scala.jar.pack.gz").!!
IO.delete(base / "sample-scala")
}
else {
s.log.warn("working tree not clean; no zip archive made")
IO.delete(base / "sample-scala.zip")
}
jar
}
cleanFiles <++= baseDirectory { base =>
Seq(base / "sample-scala.jar",
base / "sample-scala.jar.pack.gz",
base / "sample-scala.zip") }
I have an project/assembly.sbt with the contents:
addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.1")
I have a assembly.sbt in root with the contents:
import sbtassembly.AssemblyKeys._
baseAssemblySettings
In my scala code I have:
val configString = ConfigFactory.parseString(
"""
akka {
loglevel = "INFO"
actor {
provider = "akka.remote.RemoteActorRefProvider"
}
remote {
enabled-transports = ["akka.remote.netty.tcp"]
netty.tcp {
hostname = "127.0.0.1"
port = "9500"
}
log-sent-messages = on
log-received-messages = on
}
}
""".stripMargin)
val config = ConfigFactory.load(configString)
The resources folder contains an application.conf which I don't use at the moment. Greping the output of jar tf command with the expression "reference", clearly shows that reference.conf is present:
How do I package this akka example for a netlogo extension?
Note: I have included akka-actor and akka-remote as library dependencies. I am using Intellij and SBT 0.13.8 on a OS X platform.
EDIT:
After taking the advice from Ayush, I get the following output from the command sbt assembly, however the same exception is still present:

Answer 1

I think the problem is that while using sbt:assembly the default merge strategy excludes all the reference.conf files. This is what i found in documentation.
If multiple files share the same relative path (e.g. a resource named
application.conf in multiple dependency JARs), the default strategy is
to verify that all candidates have the same contents and error out
otherwise.
Can you try adding a MergeStrategy as follows
assemblyMergeStrategy in assembly := {
case PathList("reference.conf") => MergeStrategy.concat
}

Answer 2

there's an extra trick to solving this with newer akka libraries as akka does not include all their default configurations in the resource.conf
https://stackoverflow.com/a/72325132/1286583