From src/main/scala/com/typesafe/sbt/packager/linux/Keys:
val linuxMakeStartScript = TaskKey[Option[File]]("makeStartScript", "Creates or discovers the start script used by this project")
val linuxStartScriptTemplate = TaskKey[URL]("linuxStartScriptTemplate", "The location of the template start script file we use for debian (upstart or init.d")
val linuxEtcDefaultTemplate = TaskKey[URL]("linuxEtcDefaultTemplate", "The location of the /etc/default/<pkg> template script.")
val linuxJavaAppStartScriptBuilder = SettingKey[JavaAppStartScriptBuilder]("linuxJavaAppStartScriptBuilder", "Responsible for loading the start scripts. Only used with archetype.java_server")
val linuxScriptReplacements = SettingKey[Seq[(String, String)]]("linuxScriptReplacements",
"""|Replacements of template parameters used in linux scripts.
| Default supported templates:
| execScript - name of the script in /usr/bin
| author - author of this project
| descr - short description
| chdir - execution path of the script
| retries - on fail, how often should a restart be tried
| retryTimeout - pause between retries
| appName - name of application
| appClasspath - application classpath
| appMainClass - main class to start
| daemonUser - daemon user
""".stripMargin)
I would use linuxMakeStartScript
or linuxStartScriptTemplate
or linuxScriptReplacements
.