enable dockerfile build/test with CentOS 7.4 (#517)

* added Dockerfile.ngraph_cpp.centos74_cmake3, run_as_centos_user.sh, and run_as_ubuntu_user.sh to enable build/test with centos74

* added RUN_AS_USER variable as input for contrib/docker/Makefile

* moved dockerfile for centos7 to contrib/docker

* updated Makefile to take OS as a parameter from the command line for contrib/docker make targets

* fixed capability for setting OS variable on the command line for the contrib/docker/Makefile

* setting the NGRAPH_USE_PREBUILT_LLVM only if the gcc version is not 4.8

* setting NGRAPH_USE_PREBUILT_LLVM for all ubuntu builds

* updated contrib/docker/Makefile to enable the OS=centos74 override for make check_gcc

contrib/docker/Dockerfile.ngraph_cpp.centos74_cmake3

+# Environment to build and unit-test private-ngraph-cpp on centos74
+# with gcc 4.8.5
+# with python 2.7
+# with cmake3
+# LLVM/clang will be built from source
+
+FROM centos:7
+
+# Added install for perl Data::Dumper to avoid a compile error
+RUN yum -y update && \
+    yum -y --enablerepo=extras install epel-release && \
+    yum -y install \
+    gcc gcc-c++ \
+    cmake3 make \
+    git \
+    wget patch diffutils zlib-devel ncurses-devel libtinfo-dev \
+    python python-devel python-setuptools \
+    doxygen \
+    which \
+    'perl(Data::Dumper)'
+
+RUN ln -s /usr/bin/cmake3 /usr/bin/cmake
+
+RUN cmake --version
+RUN make --version
+RUN gcc --version
+RUN c++ --version
+
+RUN easy_install pip
+RUN pip install virtualenv
+
+# Install some pip packages
+RUN pip install numpy
+
+# need to use sphinx version 1.6 to build docs
+# installing with apt-get install python-sphinx installs sphinx version 1.3.6 only
+# added install for python-pip above and
+# installed sphinx with pip to get the updated version 1.6.5
+# allows for make html build under the doc/source directory as an interim build process
+RUN pip install sphinx
+
+# breathe package required to build documentation
+RUN pip install breathe
+
+WORKDIR /home

contrib/docker/Dockerfile.ngraph_cpp.ubuntu1604

+# Environment to build and unit-test private-ngraph-cpp
+
+FROM ubuntu:16.04
+
+RUN apt-get update && apt-get install -y \
+        build-essential cmake \
+        clang-3.9 clang-format-3.9 \
+        git \
+        wget patch diffutils zlib1g-dev libtinfo-dev \
+        doxygen python-pip
+
+RUN apt-get clean autoclean && \
+    apt-get autoremove -y
+RUN pip install --upgrade pip
+
+# need to use sphinx version 1.6 to build docs
+# installing with apt-get install python-sphinx installs sphinx version 1.3.6 only
+# added install for python-pip above and
+# installed sphinx with pip to get the updated version 1.6.5
+# allows for make html build under the doc/source directory as an interim build process
+RUN pip install sphinx
+RUN pip install breathe
+
+WORKDIR /home

contrib/docker/Dockerfile.ngraph_cpp.ubuntu1604_gcc48

+# Environment to build and unit-test private-ngraph-cpp
+
+FROM ubuntu:16.04
+
+RUN apt-get update && apt-get install -y \
+        build-essential cmake \
+        git \
+        wget patch diffutils zlib1g-dev libtinfo-dev \
+        doxygen python-pip
+
+RUN which gcc && gcc --version || true
+RUN which cc++ && cc++ --version || true
+
+RUN apt-get install -y gcc-4.8 gcc++-4.8
+
+RUN which gcc && gcc --version || true
+RUN which cc++ && cc++ --version || true
+
+RUN ln -s /usr/bin/gcc-4.8 /usr/bin/gcc || true
+RUN ln -s /usr/bin/cc++-4.8 /usr/bin/cc++ || true
+RUN which gcc && gcc --version || true
+RUN which cc++ && cc++ --version || true
+
+#RUN apt-get clean autoclean && \
+#    apt-get autoremove -y
+RUN pip install --upgrade pip
+
+# need to use sphinx version 1.6 to build docs
+# installing with apt-get install python-sphinx installs sphinx version 1.3.6 only
+# added install for python-pip above and
+# installed sphinx with pip to get the updated version 1.6.5
+# allows for make html build under the doc/source directory as an interim build process
+RUN pip install sphinx
+
+# breathe package required to build documentation
+RUN pip install breathe
+
+WORKDIR /home
+

contrib/docker/Makefile

 # Basic Makefile for contrib/docker. This can be expanded later as more targets
 # are added.
 
-# Default is to build with -j for parallel builds.  Turn off with
-#   make PARELLEL=
+# Default is to build with -j for parallel cmake/make.  Turn off with
+#   make PARALLEL=
 PARALLEL=-j
 
 # DIR is an internal variable that serves as an anchor to this cloned git
@@ -28,13 +28,27 @@ DBUILD_DIR = ${DIR}/contrib/docker/.build-${DBUILD_VERSION}
 
 # Enable additional options to be added on the command line
 ifndef CMAKE_OPTIONS_EXTRA
-    CMAKE_OPTIONS_EXTRA = ""
+    CMAKE_OPTIONS_EXTRA=
+endif
+
+# OS set to 'ubuntu1604' by default
+# can be overridden on the command line with 'make <target> OS=centos74"
+ifndef OS
+    OS="ubuntu1604"
+endif
+
+ifeq ("$(shell echo ${OS} | grep centos)","centos74")
+    RUN_AS_USER_SCRIPT=${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_centos_user.sh
+    DOCKERFILE=Dockerfile.ngraph_cpp.centos74_cmake3
+else
+    DOCKERFILE ?= "Dockerfile.ngraph_cpp"
+    RUN_AS_USER_SCRIPT ?= ${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_ubuntu_user.sh
 endif
 
 # For gcc builds, we do NOT regard warnings as errors
 # For clang builds, we DO make warnings into errors
 CMAKE_OPTIONS_COMMON=-DNGRAPH_BUILD_DOXYGEN_DOCS=ON -DNGRAPH_BUILD_SPHINX_DOCS=ON -DCMAKE_BUILD_TYPE=RelWithDebInfo $(CMAKE_OPTIONS_EXTRA)
-CMAKE_OPTIONS_GCC=$(CMAKE_OPTIONS_COMMON) -DNGRAPH_INSTALL_PREFIX=${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC/ngraph_dist -DNGRAPH_USE_PREBUILT_LLVM=TRUE
+CMAKE_OPTIONS_GCC=$(CMAKE_OPTIONS_COMMON) -DNGRAPH_INSTALL_PREFIX=${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC/ngraph_dist
 CMAKE_OPTIONS_CLANG=$(MAKE_OPTIONS_COMMON)-DNGRAPH_INSTALL_PREFIX=${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG/ngraph_dist -DCMAKE_CXX_COMPILER=clang++-3.9 -DCMAKE_C_COMPILER=clang-3.9 -DNGRAPH_WARNINGS_AS_ERRORS=ON -DNGRAPH_USE_PREBUILT_LLVM=TRUE
 
 CALLER_UID := $(shell id -u)
@@ -66,9 +80,12 @@ all: check_gcc check_clang
 # Docker actions
 
 expand_dockerfile_templates:
+	@echo "OS=${OS}"
+	@echo "DOCKERFILE=${DOCKERFILE}"
+	@echo "RUN_AS_USER_SCRIPT=${RUN_AS_USER_SCRIPT}"
 	cd "${DIR}"/contrib/docker
 	mkdir "${DBUILD_DIR}" || true
-	sed -e 's/\(FROM ngraph.*\)/\1:${DBUILD_VERSION}/' Dockerfile.ngraph_cpp > "${DBUILD_DIR}"/Dockerfile.build_ngraph_cpp
+	sed -e 's/\(FROM ngraph.*\)/\1:${DBUILD_VERSION}/' ${DOCKERFILE} > "${DBUILD_DIR}"/Dockerfile.build_ngraph_cpp
 
 build_docker_image: expand_dockerfile_templates
 	$(DOCKER_BUILD) -f="${DBUILD_DIR}"/Dockerfile.build_ngraph_cpp --build-arg python_version="${PYTHON_VERSION}" -t=build_ngraph_cpp:"${DBUILD_VERSION}" .
@@ -85,11 +102,11 @@ sphinx_doc: build_docker_image
 	# sphinx html docs build
 	docker run --rm --tty \
             ${VOLUME} \
-	    ${DOCKER_RUN_ENV} \
+	    {DOCKER_RUN_ENV} \
             --env RUN_UID="$(shell id -u)" \
             --env RUN_CMD="set -e ; set -o pipefail ; cd ${DOCKUSER_HOME}/ngraph-cpp-test/doc/sphinx; env VERBOSE=1 make html 2>&1 | tee make_sphinx_html.log" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-	    sh -c "${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
 # Build
 build_all: build_gcc build_clang
@@ -105,11 +122,11 @@ build_gcc: build_docker_image
 	    ${DOCKER_RUN_ENV} \
             --env GTEST_OUTPUT="xml:${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC/unit-test-results.xml" \
             --env RUN_UID="$(shell id -u)" \
-            --env RUN_CMD="set -e ; set -o pipefail ; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC; cmake ${CMAKE_OPTIONS_GCC} .. 2>&1 | tee cmake_gcc.log ; env VERBOSE=1 make ${PARALLEL} 2>&1 | tee make_gcc.log" \
+            --env RUN_CMD="set -x; set -e ; set -o pipefail ; if [ -f "/etc/centos-release" ]; then cat /etc/centos-release; fi; if [ -f "/etc/lsb-release" ]; then cat /etc/lsb-release; fi; uname -a ; cat /etc/os-release || true; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC; cmake ${CMAKE_OPTIONS_GCC} .. 2>&1 | tee cmake_gcc.log ; env VERBOSE=1 make ${PARALLEL} 2>&1 | tee make_gcc.log" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-	    sh -c "${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
-build_clang:
+build_clang: build_docker_image
 	# Remove old distribution directory if present
 	( test -d "${DIR}"/BUILD-CLANG/ngraph_dist && rm -fr "${DIR}"/BUILD-CLANG/ngraph_dist && echo "Removed old ${DIR}/BUILD-CLANG/ngraph_dist directory" ) || echo "Previous ngraph_dist directory not found"
 	# Make BUILD-CLANG directory as user
@@ -120,9 +137,9 @@ build_clang:
 	    ${DOCKER_RUN_ENV} \
             --env GTEST_OUTPUT="xml:${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG/unit-test-results.xml" \
             --env RUN_UID="$(shell id -u)" \
-            --env RUN_CMD="set -e ; set -o pipefail ; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG; cmake ${CMAKE_OPTIONS_CLANG} .. 2>&1 | tee cmake_clang.log ; env VERBOSE=1 make ${PARALLEL} 2>&1 | tee make_clang.log" \
+            --env RUN_CMD="set -e ; set -o pipefail ; if [ -f "/etc/centos-release" ]; then cat /etc/centos-release; fi; if [ -f "/etc/lsb-release" ]; then cat /etc/lsb-release; fi; uname -a ; cat /etc/os-release || true; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG; cmake ${CMAKE_OPTIONS_CLANG} .. 2>&1 | tee cmake_clang.log ; env VERBOSE=1 make ${PARALLEL} 2>&1 | tee make_clang.log" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-	    sh -c "${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
 # Check (run unit-tests)
 
@@ -134,9 +151,9 @@ check_gcc: build_gcc
 	    ${DOCKER_RUN_ENV} \
             --env GTEST_OUTPUT="xml:${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC/unit-test-results.xml" \
             --env RUN_UID="$(shell id -u)" \
-            --env RUN_CMD="set -e ; set -o pipefail ; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC; env VERBOSE=1 make check 2>&1 | tee make_check_gcc.log ; sed -E -e 's/classname\=\"[a-zA-Z0-9_]+/&1_gcc/' unit-test-results.xml > unit-test-results-gcc.xml" \
+            --env RUN_CMD="set -e ; set -o pipefail ; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC; env VERBOSE=1 make unit-test-check 2>&1 | tee make_check_gcc.log ; sed -E -e 's/classname\=\"[a-zA-Z0-9_]+/&1_gcc/' unit-test-results.xml > unit-test-results-gcc.xml" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-	    sh -c "${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
 check_clang: build_clang
 	docker run --rm --tty \
@@ -146,7 +163,17 @@ check_clang: build_clang
             --env RUN_UID="$(shell id -u)" \
             --env RUN_CMD="set -e ; set -o pipefail ; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG; env VERBOSE=1 make check 2>&1 | tee make_check_clang.log ; sed -E -e 's/classname\=\"[a-zA-Z0-9_]+/&1_clang/' unit-test-results.xml > unit-test-results-clang.xml" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-	    sh -c "${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
+
+style_clang: build_clang
+	docker run --rm --tty \
+            ${VOLUME} \
+	    ${DOCKER_RUN_ENV} \
+            --env GTEST_OUTPUT="xml:${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG/unit-test-results.xml" \
+            --env RUN_UID="$(shell id -u)" \
+            --env RUN_CMD="set -e ; set -o pipefail ; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG; env VERBOSE=1 make style-check 2>&1 | tee make_style_check_clang.log" \
+            "build_ngraph_cpp:${DBUILD_VERSION}" \
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
 # Install
 
@@ -160,7 +187,7 @@ install_gcc: check_gcc
             --env RUN_UID="$(shell id -u)" \
             --env RUN_CMD="set -e ; set -o pipefail; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-GCC ; test -d ngraph_dist && rm -fr ngraph_dist && echo 'Removed old ngraph_dist directory' ; make install 2>&1 | tee make_install_gcc.log ; tar czf ngraph_dist_gcc.tgz ngraph_dist 2>&1 | tee make_tarball_gcc.log" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-	    sh -c "${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
 install_clang: check_clang
 	# Puts ngraph_dist in BUILD-CLANG directory.  This is used by Jenkins ngraph-tensorflow batch job.
@@ -170,7 +197,7 @@ install_clang: check_clang
             --env RUN_UID="$(shell id -u)" \
             --env RUN_CMD="set -e ; set -o pipefail; cd ${DOCKUSER_HOME}/ngraph-cpp-test/BUILD-CLANG ; test -d ngraph_dist && rm -fr ngraph_dist && echo 'Removed old ngraph_dist directory' ; make install 2>&1 | tee make_install_clang.log ; tar czf ngraph_dist_clang.tgz ngraph_dist 2>&1 | tee make_tarball_clang.log" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-	    sh -c "${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
 # Interactive shell
 
@@ -181,7 +208,7 @@ shell: build_docker_image
 	    ${DOCKER_RUN_ENV} \
             --env RUN_UID="$(shell id -u)" \
             "build_ngraph_cpp:${DBUILD_VERSION}" \
-            sh -c "cd ${DOCKUSER_HOME} ; ${DOCKUSER_HOME}/ngraph-cpp-test/contrib/docker/run_as_user.sh"
+	    sh -c "cd ${DOCKUSER_HOME}; ${RUN_AS_USER_SCRIPT}"
 
 # Clean
 

contrib/docker/run_as_centos_user.sh

+#!  /bin/bash
+
+# This script is designed to simulate running as a user with a particular UID
+# within a docker container.
+#
+# Normally a docker container runs as root, which can cause problems with file
+# ownership when a host directory tree is mounted into the docker container.
+# There are other problems with building and running software as root as
+# well.  Good practice when validating software builds in a docker container
+# is to run as a normal user, since many (most?) end users will not be building
+# and installing software as root.
+#
+# This script should be run using "docker run", with RUN_UID (set to the user
+# you want to run as) passed into the docker container as an environment
+# variable.  The script will then add the UID as user "dockuser" to
+# /etc/passwd (important for some software, like bazel), add the new dockuser
+# to the sudo group (whether or not sudo is installed), and su to a new shell
+# as the dockuser (passing in the existing environment, which is important).
+#
+# If the environment variable RUN_CMD is passed into the docker container, then
+# this script will use RUN_CMD as a command to run when su'ing.  If RUN_CMD is
+# not defined, then /bin/bash will run, which effectively provides an
+# interactive shell in the docker container, for debugging.
+
+set -e  # Make sure we exit on any command that returns non-zero
+set -u  # No unset variables
+
+if [ -z "$RUN_UID" ] ; then
+
+    # >&2 redirects echo output to stderr.
+    # See: https://stackoverflow.com/questions/2990414/echo-that-outputs-to-stderr
+    ( >&2 echo 'ERROR: Environment variable RUN_UID was not set when run-as-user.sh was run' )
+    ( >&2 echo '       Running as default user (root, in docker)' )
+    ( >&2 echo ' ' )
+
+    exit 1
+
+else
+
+    # The username used in the docker container to map the caller UID to
+    #
+    # Note 'dockuser' is used in other scripts, notably Makefile.  If you
+    # choose to change it here, then you need to change it in all other
+    # scripts, or else the builds will break.
+    #
+    DOCK_USER='dockuser'
+
+    # We will be su'ing using a non-login shell or command, and preserving
+    # the environment.  This is done so that env. variables passed in with
+    # "docker run --env ..." are honored.
+    # Therefore, we need to reset at least HOME=/root ...
+    #
+    # Note also that /home/dockuser is used in other scripts, notably
+    # Makefile.  If you choose to change it here, then you need to change it
+    # in all other scripts, or else the builds will break.
+    #
+    export HOME="/home/${DOCK_USER}"
+
+    # Make sure the home directory is owned by the new user
+    if [ -d "${HOME}" ] ; then
+      chown "${RUN_UID}" "${HOME}"
+    fi
+
+    # Add a user with UID of person running docker (in ${RUN_UID})
+    # If $HOME does not yet exist, then it will be created
+    adduser -c 'Docker-User' -u "${RUN_UID}" "${DOCK_USER}"
+    passwd -d "${DOCK_USER}"
+    # Add dockuser to the sudo group.  Sudo *is* used for installing packages,
+    # so make sure dockuser can run sudo without requesting a password.
+    usermod -aG wheel "${DOCK_USER}"
+    echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+
+    if [ -z "${RUN_CMD+x}" ] ; then  # Launch a shell as dockuser
+      echo 'Running interactive shell (/bin/bash) as dockuser'
+      su -m "${DOCK_USER}" -c "/bin/bash"
+    else                         # Run command as dockuser
+      echo "Running command [${RUN_CMD}] as dockuser"
+      su -m "${DOCK_USER}" -c "${RUN_CMD}"
+    fi
+
+fi

contrib/docker/run_as_ubuntu_user.sh

+#!  /bin/bash
+
+# This script is designed to simulate running as a user with a particular UID
+# within a docker container.
+#
+# Normally a docker container runs as root, which can cause problems with file
+# ownership when a host directory tree is mounted into the docker container.
+# There are other problems with building and running software as root as
+# well.  Good practice when validating software builds in a docker container
+# is to run as a normal user, since many (most?) end users will not be building
+# and installing software as root.
+#
+# This script should be run using "docker run", with RUN_UID (set to the user
+# you want to run as) passed into the docker container as an environment
+# variable.  The script will then add the UID as user "dockuser" to
+# /etc/passwd (important for some software, like bazel), add the new dockuser
+# to the sudo group (whether or not sudo is installed), and su to a new shell
+# as the dockuser (passing in the existing environment, which is important).
+#
+# If the environment variable RUN_CMD is passed into the docker container, then
+# this script will use RUN_CMD as a command to run when su'ing.  If RUN_CMD is
+# not defined, then /bin/bash will run, which effectively provides an
+# interactive shell in the docker container, for debugging.
+
+set -e  # Make sure we exit on any command that returns non-zero
+set -u  # No unset variables
+
+if [ -z "$RUN_UID" ] ; then
+
+    # >&2 redirects echo output to stderr.
+    # See: https://stackoverflow.com/questions/2990414/echo-that-outputs-to-stderr
+    ( >&2 echo 'ERROR: Environment variable RUN_UID was not set when run-as-user.sh was run' )
+    ( >&2 echo '       Running as default user (root, in docker)' )
+    ( >&2 echo ' ' )
+
+    exit 1
+
+else
+
+    # The username used in the docker container to map the caller UID to
+    #
+    # Note 'dockuser' is used in other scripts, notably Makefile.  If you
+    # choose to change it here, then you need to change it in all other
+    # scripts, or else the builds will break.
+    #
+    DOCK_USER='dockuser'
+
+    # We will be su'ing using a non-login shell or command, and preserving
+    # the environment.  This is done so that env. variables passed in with
+    # "docker run --env ..." are honored.
+    # Therefore, we need to reset at least HOME=/root ...
+    #
+    # Note also that /home/dockuser is used in other scripts, notably
+    # Makefile.  If you choose to change it here, then you need to change it
+    # in all other scripts, or else the builds will break.
+    #
+    export HOME="/home/${DOCK_USER}"
+
+    # Make sure the home directory is owned by the new user
+    if [ -d "${HOME}" ] ; then
+      chown "${RUN_UID}" "${HOME}"
+    fi
+
+    # Add a user with UID of person running docker (in ${RUN_UID})
+    # If $HOME does not yet exist, then it will be created
+    adduser --disabled-password --gecos 'Docker-User' -u "${RUN_UID}" "${DOCK_USER}"
+    # Add dockuser to the sudo group
+    adduser "${DOCK_USER}" sudo
+
+    # If root access is needed in the docker image while running as a normal
+    # user, uncomment this and add 'sudo' as a package installed in Dockerfile
+    # echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+
+    if [ -z "${RUN_CMD+x}" ] ; then  # Launch a shell as dockuser
+      su -m "${DOCK_USER}" -c /bin/bash
+    else                         # Run command as dockuser
+      su -m "${DOCK_USER}" -c "${RUN_CMD}"
+    fi
+
+fi