#extract #docker #decompression

docker_extract

A library to extract the filesystem from a docker image

3 unstable releases

0.2.1 Mar 14, 2020
0.2.0 Feb 19, 2020
0.1.0 Feb 17, 2020

#1022 in Filesystem

24 downloads per month

MIT license

9KB
121 lines

Status

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docker-extract

docker-extract is a rust library that extracts the filesystem from a docker image.

Here is an example to extract alpine:latest to directory ./docker-fs:

use docker_extract;
use std::path::Path;

fn main() {
    let image = "alpine";
    let tag = "latest";
    let to_dir = Path::new("./docker-fs");
    docker_extract::extract_image(image, tag, &to_dir);
}

Security

This library relies on the tar crate, which is very conscious about security concerns. To prevent directory traversal issues, it will not unpack anything outside the specified output directory, i.e., paths with .. in their name will not be unpacked.

Further, docker-extract does not extract symlinks to absolute paths, as they will point to wrong references anyways.

Detailed extraction procedure

The following procedure describes what docker-extract does:

  1. Run docker save {image}:{tag} -o {tmp_dir}/image.tar
  2. Extract all layers from ${tmp_dir}/image.tar to wanted result dir
  3. Delete ${tmp_dir}

It follows, that docker-extract needs access to docker and that {image}:{tag} is already pulled.

crev

This crate has its author's crev review.

It is recommended to always use cargo-crev to verify the trustworthiness of each of your dependencies, including this one.

Dependencies

~4–13MB
~176K SLoC