bundleimages

#!/usr/bin/env bash
set -euo pipefail

show_help() {
  cat <<EOF
Reads Docker image tags from stdin, dedupes, and saves them to a tar archive.
Usage: $(basename "$0") [-o|--output file]
Examples:
  echo "postgres:13.4" | $(basename "$0") -o /path/container-images.tar
  $(basename "$0") < images.manifest
Expected format of a manifest is one image per line:
  postgres:13.4
  qdrant/qdrant:v1.13.3-gpu-nvidia
  registry.octo-cx-prod.runshiftup.com/octo-cx/common/docker-hub/coturn:25.9.18-edge-alpine

Options:
  -o, --output FILE    Output tar file path (default: /tmp/container-images-TIMESTAMP.tar)
  -h, --help          Show this help message

EOF
}

trap 'echo "Interrupted. Killing all jobs..."; kill 0; exit 1' SIGINT

archive_bundle_file="/tmp/container-images-$(date +%Y%m%d%H%M%S).tar"

while [[ $# -gt 0 ]]; do
  case $1 in
  -o|--output) archive_bundle_file="$2"; shift 2 ;;
  -h|--help) show_help; exit 0 ;;
  *) show_help >&2; exit 2 ;;
  esac
done

echo "Waiting for stdin. Run $(basename "$0") -h for help"

# normalize output path
if [[ "$archive_bundle_file" != /* ]]; then
  archive_bundle_file="$(pwd)/$archive_bundle_file"
fi

# ensure output dir exists
mkdir -p "$(dirname "$archive_bundle_file")"


save_image () {
  image=$1
  safe_filename="$(printf '%s' "$image" | tr '/:' '__')"
  image_file="$tmpdir/${safe_filename}.tar"
  docker pull "$image" >/dev/null
  docker save -o "$image_file" "$image"
}

# strip comments/blanks, dedupe
images=$(grep -vE '^\s*(#|$)' | sed 's/^\s*//;s/\s*$//' | sort -u)

# fresh workspace
tmpdir="$(mktemp -d)"
echo "Created temp dir $tmpdir"

echo "Starting pull and save..."
while IFS= read -r image_spec; do
  [[ -z "$image_spec" ]] && continue
  echo "  $image_spec"
save_image "$image_spec" &
done <<<"$images"

#synchronize
echo "Waiting for pull and save to complete (slow)"
wait
echo "Done"

echo 'Creating tar archive (slow)'
( cd "$tmpdir" && tar -cf "$archive_bundle_file" *.tar )

# compressing large files is not always the best thing to do
# zstd -T0 -q -f --rm "$archive_bundle_file" && archive_bundle_file="${archive_bundle_file}.zst"

echo "Created $archive_bundle_file in ${SECONDS} seconds"