diff --git a/Dockerfile.builder b/Dockerfile.builder
index 97dee452d9671ff8925e0a71c15bbcf99d2b30f0..3cd9e990f1c1a15641a917931ecac50076c57e54 100644
--- a/Dockerfile.builder
+++ b/Dockerfile.builder
@@ -6,9 +6,9 @@ MAINTAINER mirco.nasuti@chuv.ch
 RUN adduser --quiet --uid 1000 build
 USER build
 
-COPY ./docker/builder/build-in-docker.sh /build-in-docker.sh
+COPY ./docker/builder/build-in-docker.sh /
 
 VOLUME /opt/portal/
 WORKDIR /opt/portal/
 
-CMD ["bash", "/build-in-docker.sh"]
+CMD ["/build-in-docker.sh"]
diff --git a/docker/runner/slack.json b/docker/runner/slack.json
index 313d8c5f67f2f0650c01d29b0d3b99f360e1ab6e..d00bd5002ab568d6cbb4ccbc21a53efee176f857 100644
--- a/docker/runner/slack.json
+++ b/docker/runner/slack.json
@@ -1 +1 @@
-{"channel": "#dev-activity", "username": "webhookbot", "text": "Pushed a new version of hbpmip/portal-backend to Docker hub", "icon_emoji": ":whale:"}
+{"channel": "#dev-activity", "username": "webhookbot", "text": "${USER^} pushed a new version of hbpmip/portal-backend to Docker hub", "icon_emoji": ":whale:"}
diff --git a/docker_push.sh b/docker_push.sh
index 8da8206935b4f07fe6472722ec3814e23f433314..fdf341b3bc7d810d0abf2b7725746ddc32cb1e6a 100755
--- a/docker_push.sh
+++ b/docker_push.sh
@@ -27,4 +27,6 @@ else
 fi
 
 $CAPTAIN push --branch-tags=false --commit-tags=true portal-backend
-curl -k -X POST --data-urlencode payload@$WORKSPACE/docker/runner/slack.json https://hbps1.chuv.ch/slack/dev-activity
+eval "echo $(cat $WORKSPACE/docker/runner/slack.json)" > $WORKSPACE/target/slack.json
+curl -k -X POST --data-urlencode payload@$WORKSPACE/target/slack.json https://hbps1.chuv.ch/slack/dev-activity
+rm -f $WORKSPACE/target/slack.json