diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3c1cf164285c9093504601104c28aee5b3185737..276c6327520632af03bd645579aa0f31a08e20e4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -17,3 +17,5 @@ build:
         - python publish_images.py
     tags:
         - docker
+    only:
+        - master
diff --git a/base/centos-full:7 b/base/centos-full:7
index 3b869bd2aa35760b93fa6203678a33562f4ea5cc..8ec489491fa02f2fabbc9050b3363aefe7b96cd2 100644
--- a/base/centos-full:7
+++ b/base/centos-full:7
@@ -3,11 +3,11 @@ FROM centos:7.4.1708
 
  RUN yum install -y man sed cygpath grep test && yum clean -y all
  RUN yum install -y csh git subversion tar vim wget zsh && yum clean -y all
- RUN yum install -y ant bison compat-gcc-34-g77 flex flex-devel gcc gcc-c++ gcc-gfortran gdb glibc-static make pakchois cmake boost-devel rpmdevtools && yum clean -y all
+ RUN yum install -y ant bison compat-gcc-34-g77 flex flex-devel gcc gcc-c++ gcc-gfortran gdb glibc-static make pakchois cmake boost-devel rpmdevtools strace && yum clean -y all
  RUN yum install -y bzip2-devel gzip && yum clean -y all
  RUN yum install -y fftw-devel libgpg-error libproxy openssh-server openssl-devel && yum clean -y all
  RUN yum install -y gtk2-devel libX11  libX11-common libX11-devel libXext libXext-devel libXft libXft-devel libXpm libXpm-devel && yum clean -y all
- RUN yum install -y doxygen texlive texlive-*.noarch && yum clean -y all
+ RUN yum install -y doxygen ghostscript texlive texlive-*.noarch && yum clean -y all
 
   RUN curl -L http://proj-clhep.web.cern.ch/proj-clhep/DISTRIBUTION/tarFiles/clhep-2.2.0.8-x86_64-cc7-gcc48-opt.tgz > clhep.tgz && tar -C /usr/local/ --strip-components=1 -xvzf clhep.tgz
 
diff --git a/base/centos:7 b/base/centos:7
index 2e06be881917e8533fa753aa5766d93ccef90545..d6851c9c5b589f903235ac6817ab897b62791c47 100644
--- a/base/centos:7
+++ b/base/centos:7
@@ -2,5 +2,5 @@ FROM centos:7.4.1708
  MAINTAINER Tamas Gal <tgal@km3net.de>
 
  RUN yum install -y git subversion wget && yum clean -y all
- RUN yum install -y ant bison flex-devel gcc gcc-c++ gcc-gfortran gdb make cmake glibc-static && yum clean -y all
+ RUN yum install -y ant bison flex-devel gcc gcc-c++ gcc-gfortran gdb make cmake glibc-static strace && yum clean -y all
  RUN yum install -y doxygen && yum clean -y all
diff --git a/base/singularity:2.5 b/base/singularity:2.5
index 5bd32e22ab0a7baf99759edd717897aa2cea0895..ecabfa19b330aec1c9679c710f6f745d886ea73a 100644
--- a/base/singularity:2.5
+++ b/base/singularity:2.5
@@ -2,8 +2,7 @@ FROM debian:stretch
   MAINTAINER Tamas Gal <tgal@km3net.de>
 
   RUN apt-get update -qq && apt-get install -y wget bzip2 python-pip git
-  RUN apt-get install -y build-essential squashfs-tools libtool autotools-dev libarchive-dev automake autoconf uuid-dev libssl-dev sudo
+  RUN apt-get install -y build-essential squashfs-tools libtool autotools-dev libarchive-dev automake autoconf uuid-dev libssl-dev
 
   RUN pip install sregistry[all]
-  RUN sed -i -e 's/^Defaults\tsecure_path.*$//' /etc/sudoers
   RUN cd /tmp && git clone -b vault/release-2.5 https://www.github.com/sylabs/singularity.git && cd singularity && ./autogen.sh && ./configure --prefix=/usr/local && make && make install
diff --git a/base/texlive:2017 b/base/texlive:2017
index 815f140a66cb7073eb1c07fe6bc37146711d18af..cf6454bde2d30efac9abf5b13760b1573ca2fb38 100644
--- a/base/texlive:2017
+++ b/base/texlive:2017
@@ -7,9 +7,8 @@ ARG BUILD_DATE
 LABEL org.label-schema.build-date=$BUILD_DATE \
       maintainer="Tamas Gal <tgal@km3net.de>"
 
-
-RUN apt-get update \
-  && apt-get install -y gnupg wget curl git make libgetopt-long-descriptive-perl \
+RUN apt-get update
+RUN apt-get install -y gnupg wget curl git make libgetopt-long-descriptive-perl \
   libdigest-perl-md5-perl python-pygments fontconfig && rm -rf /var/lib/apt/lists/*
   
 WORKDIR /