# docker-repack - Speed up Docker image pulls

This tool repacks a Docker image into a smaller, more efficient version that makes it significantly faster to pull. It 
does this by using a few [different techniques](docs/about.md) such as removing redundant data and improving compression 
ratios. Some examples of improvements:

| Image                                                                           | Before                       | After             | Reduction                 |
|---------------------------------------------------------------------------------|------------------------------|-------------------|---------------------------|
| [google/deepsomatic](https://registry.hub.docker.com/r/google/deepsomatic/tags) | 16.4GB, 2 minutes 14 seconds | 4.8GB, 16 seconds | 3.4x smaller, 8.2x faster |
| [google/deepvariant](https://hub.docker.com/r/google/deepvariant/tags)          | 12.7GB, 1 minute, 2 seconds  | 3GB, 10 seconds   | 6.3x faster, 4.2x smaller |
| [google/cloud-sdk](https://registry.hub.docker.com/r/google/cloud-sdk/tags)     | 1.1GB, 5 seconds             | 187MB, 1 second   | 3.8x faster, 6.1x smaller |
| [mathworks/matlab](https://hub.docker.com/r/mathworks/matlab/tags)              | 2GB, 5 seconds               | 230.7MB, 1 second | 6.5x faster, 9x smaller   |
| [tensorflow/tensorflow](https://hub.docker.com/r/tensorflow/tensorflow/tags)    | 3.5GB, 11 seconds            | 2GB, 3 seconds    | 3.3x faster, 1.8x smaller |

See the [benchmarks page](https://orf.github.io/docker-repack/benchmarks/) for a full comparison of pulling times across
many different images.

![](./docs/preview.gif)

## Usage

```bash
$ docker-repack docker://alpine:latest oci://directory/ --target-size=50MB
```

Full arguments:

```bash
Usage: docker-repack [OPTIONS] --target-size <TARGET_SIZE> <SOURCE> <OUTPUT_DIR>

Arguments:
  <SOURCE>      Source image. e.g. `python:3.11`, `tensorflow/tensorflow:latest` or `oci://local/image/path`
  <OUTPUT_DIR>  Location to save image, e.g oci://directory/path/

Options:
  -t, --target-size <TARGET_SIZE>              Target size for layers
      --concurrency <CONCURRENCY>
      --keep-temp-files
      --compression-level <COMPRESSION_LEVEL>  [default: 14]
      --platform <PLATFORM>                    [default: linux/*]
  -h, --help                                   Print help
  -V, --version                                Print version
  ```

## Installation

### Pre-compiled binaries

Download a release [from the releases page](https://github.com/orf/docker-repack/releases)

### Cargo

```bash
cargo install docker-repack
````