diff --git a/Dockerfile b/Dockerfile
index 8b77628..c6a1fe8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,31 +6,32 @@
     DEBCONF_NONINTERACTIVE_SEEN=true \
     LANG=C.UTF-8 \
     LANGUAGE=$LANG
-SHELL ["/bin/bash", "-xeo", "pipefail", "-c"]
+SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
 USER root
 RUN mkdir -p /var/lib/cvp-sanity/
 COPY cvp-sanity/ /var/lib/cvp-sanity
+ARG UBUNTU_MIRROR_URL="http://archive.ubuntu.com/ubuntu"
 
 WORKDIR /var/lib/
 
-RUN pushd /etc/apt/ && echo > sources.list && \
-  echo 'Acquire::Languages "none";' > apt.conf.d/docker-no-languages && \
-  echo 'Acquire::GzipIndexes "true"; Acquire::CompressionTypes::Order:: "gz";' > apt.conf.d/docker-gzip-indexes && \
-  echo 'APT::Get::Install-Recommends "false"; APT::Get::Install-Suggests "false";' > apt.conf.d/docker-recommends && \
-  echo "deb [arch=amd64] http://cz.archive.ubuntu.com/ubuntu xenial main restricted universe multiverse" >> sources.list && \
-  echo "deb [arch=amd64] http://cz.archive.ubuntu.com/ubuntu xenial-updates main restricted universe multiverse" >> sources.list && \
-  echo "deb [arch=amd64] http://cz.archive.ubuntu.com/ubuntu xenial-backports main restricted universe multiverse" >> sources.list && \
-  popd ; apt-get update && apt-get  upgrade -y && \
-  apt-get install -y curl git-core iputils-ping libffi-dev libldap2-dev libsasl2-dev libssl-dev patch python-dev python-pip python3-dev vim-tiny wget \
-  python-virtualenv python3-virtualenv && \
+RUN set -ex; pushd /etc/apt/ && echo > sources.list && \
+    echo 'Acquire::Languages "none";' > apt.conf.d/docker-no-languages && \
+    echo 'Acquire::GzipIndexes "true"; Acquire::CompressionTypes::Order:: "gz";' > apt.conf.d/docker-gzip-indexes && \
+    echo 'APT::Get::Install-Recommends "false"; APT::Get::Install-Suggests "false";' > apt.conf.d/docker-recommends && \
+    echo "deb [arch=amd64] $UBUNTU_MIRROR_URL xenial main restricted universe multiverse" >> sources.list && \
+    echo "deb [arch=amd64] $UBUNTU_MIRROR_URL xenial-updates main restricted universe multiverse" >> sources.list && \
+    echo "deb [arch=amd64] $UBUNTU_MIRROR_URL xenial-backports main restricted universe multiverse" >> sources.list && \
+    popd ; apt-get update && apt-get  upgrade -y && \
+    apt-get install -y curl git-core iputils-ping libffi-dev libldap2-dev libsasl2-dev libssl-dev patch python-dev python-pip python3-dev vim-tiny wget \
+    python-virtualenv python3-virtualenv && \
 #Due to upstream bug we should use fixed version of pip
-  python -m pip install --upgrade 'pip==9.0.3' && \
-  pip install -r cvp-sanity/requirements.txt && \
+    python -m pip install --upgrade 'pip==9.0.3' && \
+    pip install -r cvp-sanity/requirements.txt && \
 # Cleanup
-  apt-get -y purge libx11-data xauth libxmuu1 libxcb1 libx11-6 libxext6 ppp pppconfig pppoeconf popularity-contest cpp gcc g++ libssl-doc && \
-  apt-get -y autoremove; apt-get -y clean ; rm -rf /root/.cache; rm -rf /var/lib/apt/lists/* && \
-  rm -rf /tmp/* ; rm -rf /var/tmp/* ; rm -rfv /etc/apt/sources.list.d/* ; echo > /etc/apt/sources.list
+    apt-get -y purge libx11-data xauth libxmuu1 libxcb1 libx11-6 libxext6 ppp pppconfig pppoeconf popularity-contest cpp gcc g++ libssl-doc && \
+    apt-get -y autoremove; apt-get -y clean ; rm -rf /root/.cache; rm -rf /var/lib/apt/lists/* && \
+    rm -rf /tmp/* ; rm -rf /var/tmp/* ; rm -rfv /etc/apt/sources.list.d/* ; echo > /etc/apt/sources.list
 COPY bin /usr/local/bin/
 ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
 # docker build --no-cache -t cvp-sanity-checks:$(date "+%Y_%m_%d_%H_%M_%S") .