Simple Bash Script Template to Run a Script inside a Docker Container Once

one-time-docker.bash

#!/usr/bin/env bash


set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then
    set -o xtrace
fi

if [[ "${1-}" =~ ^-*h(elp)?$ ]]; then
    echo 'Usage: ./one-time-docker

This script is a template to
  - one time run a docker container,
  - execute a script inside, 
  - save some output to ./output, and
  - delete the container afterwards.

Adjust as needed.

Use:
export TRACE=1
for better debugging.
'
    exit
fi


# Set variables
IMAGE="docker.io/library/debian:stable-slim"
HOST_OUTPUT_DIR="./output"
ARTIFACT_PATH="/output/artifact.txt"
USER_ID=$(id -u)
GROUP_ID=$(id -g)

# Make sure output directory exists
mkdir --parents "${HOST_OUTPUT_DIR}"

# Create a temporary file to hold the container script
SCRIPT_FILE=$(mktemp)

# YOUR SCRIPT HERE ###########################################################
cat <<EOF > "${SCRIPT_FILE}"
mkdir --parents /output
echo 'Hello from inside the container!' > ${ARTIFACT_PATH}
EOF
##############################################################################

# Run the container, generate the artifact, and copy it out
docker container run \
  --rm \
  --user "${USER_ID}:${GROUP_ID}" \
  --mount type=bind,source="${HOST_OUTPUT_DIR}",target=/output \
  --mount type=bind,source="${SCRIPT_FILE}",target=/container_script.sh,readonly \
  "${IMAGE}" \
  bash /container_script.sh

# Clean up the temporary script file
rm --force "${SCRIPT_FILE}"

echo "Artifact extracted to: ${HOST_OUTPUT_DIR}"