Extract fs from ECR

extract-from-ecr.sh

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

if [[ $# -ne 1 ]]; then
  echo "Usage: $0 <image>"
  echo "Example: $0 806377085208.dkr.ecr.eu-central-1.amazonaws.com/my-repo:latest"
  exit 1
fi

IMAGE="$1"
REGISTRY="${IMAGE%%/*}"
REGION="$(echo "$REGISTRY" | sed -E 's#^[0-9]+\.dkr\.ecr\.([^.]+)\.amazonaws\.com$#\1#')"

if [[ "$REGISTRY" == "$IMAGE" || -z "$REGION" || "$REGION" == "$REGISTRY" ]]; then
  echo "Could not parse ECR registry/region from image: $IMAGE"
  exit 1
fi

aws ecr get-login-password --region "$REGION" | docker login --username AWS --password-stdin "$REGISTRY"

docker pull "$IMAGE"

CONTAINER_ID="$(docker create "$IMAGE")"

docker cp "${CONTAINER_ID}":/ ./image-rootfs
docker rm "$CONTAINER_ID"