Singularity.def

Bootstrap: library
From: ubuntu:18.04
Stage: build

# https://www.sylabs.io/guides/3.2/user-guide/definition_files.html

%setup
    touch /file1
    touch ${SINGULARITY_ROOTFS}/file2

%files
    /file1
    /file1 /opt

%environment
    export LISTEN_PORT=12345
    export LC_ALL=C

%post
    apt-get update && apt-get install -y netcat
    NOW=`date`
    echo "export NOW=\"${NOW}\"" >> $SINGULARITY_ENVIRONMENT

%runscript
    echo "Container was created $NOW"
    echo "Arguments received: $*"
    exec echo "$@"

%startscript
    nc -lp $LISTEN_PORT

%test
    grep -q NAME="Ubuntu" /etc/os-release
    if [ $? -eq 0 ]; then
        echo "Container base is Ubuntu as expected."
    else
        echo "Container base is not Ubuntu."
    fi

%labels
    Author d@sylabs.io
    Version v0.0.1

%help
    This is a demo container used to illustrate a def file that uses all
    supported sections.

# Taken from: https://github.com/onnovalkering/vscode-singularity/blob/master/test/Singularity