diff --git a/packaging/README.md b/packaging/README.md
index 3a6aadf..d393fff 100644
--- a/packaging/README.md
+++ b/packaging/README.md
@@ -31,17 +31,13 @@ inside the synergy-service directory.
 
       docker build -t synergy-centos7-builder .
 
-- edit the file `synergy-service/packaging/docker/build_env.sh` to define environment variables.
-
 - launch the container
 
       docker run -i -v /path/to/synergy-service:/tmp/synergy-service \
-                 --env-file=/path/to/synergy-service/packaging/docker/build_env.sh \
                  synergy-centos7-builder
 
   This actually mount the synergy-service directory to `/tmp/synergy-service` on
   the guest.
-  It also loads environment variables from the `build_env.sh` file.
 
 - the resulting rpm should be in the build directory if successful
 
@@ -56,12 +52,10 @@ inside the synergy-service directory.
 
       docker build -t synergy-ubuntu14.04-builder .
 
-- edit the file `synergy-service/packaging/docker/build_env.sh` to define environment variables.
 
 - launch the container
 
       docker run -i -v /path/to/synergy-service:/tmp/synergy-service \
-                 --env-file=/path/to/synergy-service/packaging/docker/build_env.sh \
                  synergy-ubuntu14.04-builder
 
 - the resulting deb should be in the build directory if successful
diff --git a/packaging/docker/build_env.sh b/packaging/docker/build_env.sh
deleted file mode 100644
index debab0b..0000000
--- a/packaging/docker/build_env.sh
+++ /dev/null
@@ -1 +0,0 @@
-PKG_VERSION=1.0.1
diff --git a/packaging/docker/centos7/Dockerfile b/packaging/docker/centos7/Dockerfile
index 14dee62..f8cdedc 100644
--- a/packaging/docker/centos7/Dockerfile
+++ b/packaging/docker/centos7/Dockerfile
@@ -1,6 +1,6 @@
 FROM centos:7
 MAINTAINER Vincent Llorens <vincent.llorens@cc.in2p3.fr>
-RUN yum install -y https://repos.fedorapeople.org/repos/openstack/openstack-liberty/rdo-release-liberty-3.noarch.rpm \
+RUN yum install -y centos-release-openstack-liberty \
                    rpm-build \
                    python-devel \
                    python-setuptools \
diff --git a/packaging/docker/centos7/build.sh b/packaging/docker/centos7/build.sh
index f85d9d4..94f4ed8 100644
--- a/packaging/docker/centos7/build.sh
+++ b/packaging/docker/centos7/build.sh
@@ -4,11 +4,16 @@ set -e -x
 RPMBUILD=/home/pkger/rpmbuild
 PKG_DIR=/tmp/synergy-service
 
+function get_version() {
+    local file=$PKG_DIR/setup.cfg
+    export PKG_VERSION=$(grep -e "version = " $file | sed -r "s/version = ()/\1/")
+}
+
 function setup() {
     mkdir -p /home/pkger/rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
     cd $RPMBUILD/SOURCES/
     cp -r $PKG_DIR python-synergy-service-$PKG_VERSION
-    rm -r python-synergy-service-$PKG_VERSION/build || true
+    rm -r python-synergy-service-$PKG_VERSION/{.tox,.testrepository,build,dist} || true
     tar cjf python-synergy-service-${PKG_VERSION}.tar.bz2 python-synergy-service-$PKG_VERSION
     cp $PKG_DIR/packaging/rpm/python-synergy.spec $RPMBUILD/SPECS/python-synergy.spec
 }
@@ -25,6 +30,7 @@ function clean() {
     rm -rf $RPMBUILD
 }
 
-clean
+clean || true
+get_version
 setup
 build
diff --git a/packaging/docker/ubuntu-14.04/build.sh b/packaging/docker/ubuntu-14.04/build.sh
index df1b17b..eaf590d 100644
--- a/packaging/docker/ubuntu-14.04/build.sh
+++ b/packaging/docker/ubuntu-14.04/build.sh
@@ -3,12 +3,21 @@ set -e -x
 
 PKG_DIR=/tmp/synergy-service
 
+function copy_source() {
+    cd /home/pkger
+    cp -r $PKG_DIR python-synergy-service
+    rm -r python-synergy-service/{.tox,.testrepository,build,dist} || true
+}
+
+function get_version() {
+    local file=/home/pkger/python-synergy-service/setup.cfg
+    export PKG_VERSION=$(grep -e "version = " $file | sed -r "s/version = ()/\1/")
+}
+
 function setup() {
     cd /home/pkger
-    cp -r $PKG_DIR synergy-service
-    tar cfz python-synergy-service_${PKG_VERSION}.orig.tar.gz synergy-service
-    mv synergy-service python-synergy-service
-    cp -r python-synergy-service/packaging/debian python-synergy-service/debian
+    tar cjf python-synergy-service_${PKG_VERSION}.orig.tar.bz2 python-synergy-service
+    mv python-synergy-service/packaging/debian python-synergy-service/debian
 }
 
 function build() {
@@ -19,9 +28,11 @@ function build() {
 }
 
 function clean() {
-    rm -r /home/pkger/python-synergy-service*
+    rm -r /home/pkger/python-synergy-service{,_${PKG_VERSION}.orig.tar.bz2}
 }
 
+clean || true
+copy_source
+get_version
 setup
 build
-clean