Possible improvement for #1202

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

@@ -369,14 +369,22 @@ object DockerPlugin extends AutoPlugin {
                                 gidOpt: Option[String]): CmdLike =
     Cmd(
       "RUN",
-      (List("id", "-u", daemonUser, "2>", "/dev/null", "||") :::
+      (List("id", "-u", daemonUser, "1>/dev/null", "2>&1", "||") :::
         (gidOpt.fold[List[String]](Nil)(
-        gid => List("((", "getent", "group", gid, "||", "groupadd", "-g", gid, daemonGroup, ")", "&&")
+        gid =>
+          List("((", "getent", "group", gid, "1>/dev/null", "2>&1", "||") :::
+            List("(", "type", "groupadd", "1>/dev/null", "2>&1", "&&") :::
+            List("groupadd", "-g", gid, daemonGroup, "||") :::
+            List("addgroup", "-g", gid, "-S", daemonGroup, "))", "&&")
       )) :::
+        List("(", "type", "useradd", "1>/dev/null", "2>&1", "&&") :::
         List("useradd", "--system", "--create-home") :::
         (uidOpt.fold[List[String]](Nil)(List("--uid", _))) :::
         (gidOpt.fold[List[String]](Nil)(List("--gid", _))) :::
-        List(daemonUser, ")")): _*
+        List(daemonUser, "||") :::
+        List("adduser", "-S") :::
+        (uidOpt.fold[List[String]](Nil)(List("-u", _))) :::
+        List("-G", daemonGroup, daemonUser, "))")): _*
     )
 
   /**

src/sbt-test/docker/file-permission/build.sbt

@@ -23,7 +23,7 @@ lazy val root = (project in file("."))
           |
           |FROM fabric8/java-centos-openjdk8-jdk
           |USER root
-          |RUN id -u demiourgos728 2> /dev/null || (( getent group 0 || groupadd -g 0 root ) && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 )
+          |RUN id -u demiourgos728 1>/dev/null 2>&1 || (( getent group 0 1>/dev/null 2>&1 || ( type groupadd 1>/dev/null 2>&1 && groupadd -g 0 root || addgroup -g 0 -S root )) && ( type useradd 1>/dev/null 2>&1 && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 || adduser -S -u 1001 -G root demiourgos728 ))
           |WORKDIR /opt/docker
           |COPY --from=stage0 --chown=demiourgos728:root /opt/docker /opt/docker
           |USER 1001:0
@@ -37,7 +37,7 @@ lazy val root = (project in file("."))
       assertEquals(lines,
         """FROM fabric8/java-centos-openjdk8-jdk
           |USER root
-          |RUN id -u demiourgos728 2> /dev/null || (( getent group 0 || groupadd -g 0 root ) && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 )
+          |RUN id -u demiourgos728 1>/dev/null 2>&1 || (( getent group 0 1>/dev/null 2>&1 || ( type groupadd 1>/dev/null 2>&1 && groupadd -g 0 root || addgroup -g 0 -S root )) && ( type useradd 1>/dev/null 2>&1 && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 || adduser -S -u 1001 -G root demiourgos728 ))
           |WORKDIR /opt/docker
           |COPY opt /opt
           |USER 1001:0
@@ -51,7 +51,7 @@ lazy val root = (project in file("."))
       assertEquals(lines,
         """FROM fabric8/java-centos-openjdk8-jdk
           |USER root
-          |RUN id -u demiourgos728 2> /dev/null || (( getent group 5000 || groupadd -g 5000 sbt ) && useradd --system --create-home --uid 1001 --gid 5000 demiourgos728 )
+          |RUN id -u demiourgos728 1>/dev/null 2>&1 || (( getent group 5000 1>/dev/null 2>&1 || ( type groupadd 1>/dev/null 2>&1 && groupadd -g 5000 sbt || addgroup -g 5000 -S sbt )) && ( type useradd 1>/dev/null 2>&1 && useradd --system --create-home --uid 1001 --gid 5000 demiourgos728 || adduser -S -u 1001 -G sbt demiourgos728 ))
           |WORKDIR /opt/docker
           |COPY opt /opt
           |USER 1001:5000
@@ -65,7 +65,7 @@ lazy val root = (project in file("."))
       assertEquals(lines,
         """FROM openjdk:8
           |USER root
-          |RUN id -u demiourgos728 2> /dev/null || (( getent group 0 || groupadd -g 0 root ) && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 )
+          |RUN id -u demiourgos728 1>/dev/null 2>&1 || (( getent group 0 1>/dev/null 2>&1 || ( type groupadd 1>/dev/null 2>&1 && groupadd -g 0 root || addgroup -g 0 -S root )) && ( type useradd 1>/dev/null 2>&1 && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 || adduser -S -u 1001 -G root demiourgos728 ))
           |WORKDIR /opt/docker
           |COPY opt /opt
           |RUN ["chmod", "-R", "u=rX,g=rX", "/opt/docker"]
@@ -100,7 +100,7 @@ lazy val root = (project in file("."))
           |
           |FROM fabric8/java-centos-openjdk8-jdk
           |USER root
-          |RUN id -u demiourgos728 2> /dev/null || (( getent group 0 || groupadd -g 0 root ) && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 )
+          |RUN id -u demiourgos728 1>/dev/null 2>&1 || (( getent group 0 1>/dev/null 2>&1 || ( type groupadd 1>/dev/null 2>&1 && groupadd -g 0 root || addgroup -g 0 -S root )) && ( type useradd 1>/dev/null 2>&1 && useradd --system --create-home --uid 1001 --gid 0 demiourgos728 || adduser -S -u 1001 -G root demiourgos728 ))
           |WORKDIR /opt/docker
           |COPY --from=stage0 --chown=demiourgos728:root /opt/docker /opt/docker
           |USER 1001:0

src/sbt-test/docker/test-busybox-create-user/build.sbt

@@ -0,0 +1,13 @@
+
+enablePlugins(JavaAppPackaging)
+
+name := "test-busybox-create-user"
+
+version := "0.1.0"
+
+maintainer := "Boris Capitanu <[email protected]>"
+dockerBaseImage := "anapsix/alpine-java:8"
+daemonUserUid in Docker := Some("2000")
+daemonUser in Docker := "appuser"
+daemonGroupGid in Docker := Some("3000")
+daemonGroup in Docker    := "appgroup"

src/sbt-test/docker/test-busybox-create-user/project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % sys.props("project.version"))

src/sbt-test/docker/test-busybox-create-user/src/main/scala/Main.scala

@@ -0,0 +1,5 @@
+import com.sun.security.auth.module.UnixSystem
+
+object Main extends App {
+  println(System.getProperty("user.name"))
+}

src/sbt-test/docker/test-busybox-create-user/test

@@ -0,0 +1,3 @@
+# Generate the Docker image locally
+> docker:publishLocal
+$ exec bash -c 'docker run test-busybox-create-user:0.1.0 | grep -q "appuser"'