Introduction
Ever needed to retrieve a Dockerfile or specific content from an old Docker image stored in an AWS ECR repository? This guide provides a straightforward approach using Docker commands to pull the image, access its contents, and extract files as needed.
Pulling a Docker Image from AWS ECR
Start by pulling the Docker image from your AWS ECR repository with the following command:
docker pull YOUR_DOCKER_IMAGE_URL
Replace YOUR_DOCKER_IMAGE_URL with the actual URL of your Docker image.
Executing Commands Within the Docker Image
To run commands inside the Docker image without making any permanent changes, use:
docker run --rm -it --entrypoint=/bin/bash YOUR_DOCKER_IMAGE_URL
For example, to list all files and directories in the root of the image:
docker run --rm -it --entrypoint=/bin/bash YOUR_DOCKER_IMAGE_URL -c "ls -la"
Extracting and Searching Within the Docker Image
To save the Docker image as a tar file:
docker image save YOUR_DOCKER_IMAGE_URL > img.tar
Following this, extract the tar file to access the image’s filesystem:
tar -xvf img.tar
This method allows you to navigate through the extracted files and directories to locate specific data or configurations contained in the Docker image.
By following these steps, you can effectively manage and inspect Docker images stored in AWS ECR, ensuring you have access to all necessary components of your Docker environment.
