test.sh

#!/usr/bin/env bash

dockerfile=$(mktemp)

on_exit() {
    echo "Removing $dockerfile";
    rm -f $dockerfile
}

on_sigint() {
    echo "SIGINT received. Exiting...";
    exit 0
}

trap on_sigint SIGINT
trap on_exit EXIT

cat <<'EOF' > $dockerfile
FROM ubuntu:22.04

# Create a script that generates sample data and then ignores SIGTERM
RUN echo '#!/bin/bash\n\
SIZE_MB=${1:-100}  # Default to 100MB if no size specified\n\
\n\
echo "Generating ${SIZE_MB}MB of sample data..."\n\
dd if=/dev/urandom of=/data.bin bs=1M count=$SIZE_MB\n\
echo "Generated ${SIZE_MB}MB of data at /data.bin"\n\
\n\
trap "" SIGTERM\n\
echo "Started process that ignores SIGTERM"\n\
while true; do\n\
    echo "Still running... (will ignore SIGTERM)"\n\
    sleep 1\n\
done' > /entrypoint.sh

# Make the script executable
RUN chmod +x /entrypoint.sh

# Run the script with default 100MB
CMD ["/entrypoint.sh"]
EOF

# Build and run
docker build -t unstoppable -f $dockerfile .

# Try to stop it and observe the delay
# time docker stop test

set -ex

for i in {1..100}; do
    # time docker kill test || true
    # time docker stop -t 20 test || true
    time docker rm -f test
    docker run --init -d --name test unstoppable /entrypoint.sh 101 || (docker logs test; docker inspect test; exit 1)
    sleep 1
done