#!/bin/bash

# Filename: /usr/local/bin/python-docker
# Script to run python:latest inside an ephemeral docker container
# pip install python modules if requirements.txt is preset

# do not continue script on errors
set -euo pipefail

# Python version to run from docker hub
X_PYTHON_VERSION="latest"

# Get current user details so we can run python with this user id later
X_UID=$(id -u)
X_USERNAME=$(id -un)

# Set docker container name to basename of current working dir + random string
NAME=$(echo $(basename "${PWD}" ).${RANDOM})

# Create temporary docker ENTRYPOINT shell script
X_TMPDIR="$(mktemp -d)"
ENTRYPOINT="${X_TMPDIR}/entrypoint.sh"
# Remove temp files on exit
trap "{ rm -rf ${X_TMPDIR}; }" EXIT

cat > "${ENTRYPOINT}" <<EOF
#!/bin/bash

# Alternate entrypoint for python docker image
# Run pip as root, then run python as X_USERNAME

# do not continue script on errors
set -euo pipefail

# Optimize pip for docker usage
export ENV PIP_DISABLE_PIP_VERSION_CHECK=1
export ENV PIP_NO_CACHE_DIR=1

# create the current user in the container
useradd -u ${X_UID} -U -s /bin/bash -M ${X_USERNAME}

# pip install modules if requirements.txt is present
[ -f requirements.txt ] && pip install -r requirements.txt

# run python
exec su -c "python $@" ${X_USERNAME}
EOF

chmod 755 ${ENTRYPOINT}

# Run python in docker with all the containers set

docker run -it --rm \
	-v /etc/timezone:/etc/timezone:ro \
	-v /etc/localtime:/etc/localtime:ro \
	-v /data:/data -v /home:/home \
	-v ${X_TMPDIR}:${X_TMPDIR} \
	-w $(pwd) \
	--entrypoint "${ENTRYPOINT}" \
	--name ${NAME} \
	--net=host \
	python:X_PYTHON_VERSION "$@"