diff --git a/Dockerfile b/Dockerfile
index 6ebf961..6baa7b8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,8 @@
 #!BuildTag: opensuse/openjdk:%%PKG_VERSION%%
 #!BuildTag: opensuse/openjdk:%%PKG_VERSION%%.%RELEASE%
 
-FROM opensuse/tumbleweed
+ARG BASE=opensuse/tumbleweed
+FROM $BASE
 
 # labelprefix=org.opensuse.openjdk
 PREFIXEDLABEL org.opencontainers.image.title="Java 15 development container"
@@ -14,9 +15,17 @@ PREFIXEDLABEL org.openbuildservice.disturl="%DISTURL%"
 PREFIXEDLABEL org.opensuse.reference="registry.opensuse.org/opensuse/openjdk:%%PKG_VERSION%%.%RELEASE%"
 
 # Work around https://github.com/openSUSE/obs-build/issues/487
-RUN zypper install -y openSUSE-release-appliance-docker
+ARG RELEASE_PACKAGE=openSUSE-release-appliance-docker
+
+ARG LIBDIR=/usr/lib64
+ENV JAVA_BINDIR=$LIBDIR/jvm/java/bin
+ENV JAVA_HOME=$LIBDIR/jvm/java
+ENV JAVA_ROOT=$LIBDIR/jvm/java
+ENV JAVA_VERSION=15
 
 # Development packages
-RUN zypper install -y --no-recommends java-15-openjdk-devel maven git-core
+RUN zypper -n install --no-recommends $RELEASE_PACKAGE \
+	java-15-openjdk-devel maven git-core && \
+	zypper clean -a
 
-ENTRYPOINT [ "/bin/bash" ]
+CMD [ "jshell" ]
diff --git a/java15-devel-container.changes b/java15-devel-container.changes
index 00e2ca6..0f3d1ce 100644
--- a/java15-devel-container.changes
+++ b/java15-devel-container.changes
@@ -1,15 +1,29 @@
 -------------------------------------------------------------------
-Wed Mar 24 12:19:36 UTC 2021 - Marco Varlese <marco.varlese@suse.com>
+Tue Apr 27 08:58:40 UTC 2021 - Dirk Müller <dmueller@suse.com>
+
+- stop specifying an entrypoint, these aren't services
+- use single layer
+- zypper clean after install
+- provide JAVA_VERSION, JAVA_ROOT and JAVA_HOME env
+
+-------------------------------------------------------------------
+Wed Mar 24 12:21:53 UTC 2021 - Marco Varlese <marco.varlese@suse.com>
 
 - Renamed tag to follow upstream
 
 -------------------------------------------------------------------
-Tue Mar 23 19:25:53 UTC 2021 - Marco Varlese <marco.varlese@suse.com>
+Tue Mar 23 19:28:04 UTC 2021 - Marco Varlese <marco.varlese@suse.com>
 
 - Not having "opensuse" as prefix does not conform to specification as per conversation with fvogt
 
 -------------------------------------------------------------------
-Fri Mar 19 14:40:35 UTC 2021 - Marco Varlese <marco.varlese@suse.com>
+Mon Mar 22 13:28:11 UTC 2021 - Frederic Crozat <fcrozat@suse.com>
+
+- Allow to override base container and release package using
+  Docker arguments.
+
+-------------------------------------------------------------------
+Fri Mar 19 14:41:07 UTC 2021 - Marco Varlese <marco.varlese@suse.com>
 
 - Added ENTRY_POINT