Give an absolute path to the entrypoint

Author: joan38

src/main/scala/com/typesafe/sbt/packager/docker/DockerPlugin.scala

@@ -80,7 +80,7 @@ object DockerPlugin extends AutoPlugin {
       Some((version in Docker).value)
     ),
     dockerUpdateLatest := false,
-    dockerEntrypoint := Seq("bin/%s" format executableScriptName.value),
+    dockerEntrypoint := Seq(s"${(defaultLinuxInstallLocation in Docker).value}/bin/${executableScriptName.value}"),
     dockerCmd := Seq(),
     dockerExecCommand := Seq("docker"),
     dockerVersion := Try(Process(dockerExecCommand.value ++ Seq("version", "--format", "'{{.Server.Version}}'")).!!).toOption

src/sbt-test/docker/test-executableScriptName/build.sbt

@@ -13,7 +13,7 @@ maintainer := "Gary Coady <[email protected]>"
 TaskKey[Unit]("checkDockerfile") := {
   val dockerfile = IO.read((stagingDirectory in Docker).value / "Dockerfile")
   assert(
-    dockerfile.contains("ENTRYPOINT [\"bin/docker-exec\"]\n"),
+    dockerfile.contains("ENTRYPOINT [\"/opt/docker/bin/docker-exec\"]\n"),
     "dockerfile doesn't contain ENTRYPOINT [\"docker-exec\"]\n" + dockerfile
   )
   streams.value.log.success("Successfully tested control script")