diff

#!/bin/bash
set -e

usage() {
cat << EOF
Usage: $0 [OPTIONS]
Compare a given Docker image package versions against the prod image.

Options:
    -g, --gpu       Compare GPU images.
    -t, --target    The image to diff against the prod image.
                    Default is the locally built image.
EOF
}


BASE_IMAGE_TAG='gcr.io/kaggle-images/python:latest'
TARGET_IMAGE_TAG='kaggle/python-build'
TARGET_IMAGE_TAG_OVERRIDE=''

while :; do
    case "$1" in 
        -h|--help)
            usage
            exit
            ;;
        -g|--gpu)
            BASE_IMAGE_TAG='gcr.io/kaggle-private-byod/python:latest'
            TARGET_IMAGE_TAG='kaggle/python-gpu-build'
            ;;
        -t|--target)
            if [[ -z "$2" ]]; then
                usage
                printf 'ERROR: No IMAGE specified after the %s flag.\n' "$1" >&2
                exit
            fi
            TARGET_IMAGE_TAG_OVERRIDE="$2"
            shift # skip the flag value
            ;;
        -?*)
            usage
            printf 'ERROR: Unknown option: %s\n' "$1" >&2
            exit
            ;;
        *)            
            break
    esac

    shift
done

if [[ -n "$TARGET_IMAGE_TAG_OVERRIDE" ]]; then
    TARGET_IMAGE_TAG="$TARGET_IMAGE_TAG_OVERRIDE"
fi

readonly BASE_IMAGE_TAG
readonly TARGET_IMAGE_TAG

echo "Base: $BASE_IMAGE_TAG"
echo "Target: $TARGET_IMAGE_TAG"

docker pull "$BASE_IMAGE_TAG"

CMDS=('dpkg-query --show -f "${Package}==${Version}\n"' 'pip freeze')
for cmd in "${CMDS[@]}"; do
    echo "== Comparing $cmd =="
    diff --suppress-common-lines --side-by-side \
        <(docker run --rm "$BASE_IMAGE_TAG" $cmd) \
        <(docker run --rm "$TARGET_IMAGE_TAG" $cmd) \
        && echo 'No diff' || true
done