fray

Resumable OCI image pulls for unreliable networks.

The Problem

OCI image layers can be massive - bootc OS images often have layers of 800MB or more. On unreliable edge networks, a failed pull means starting over.

How Fray Solves It

Fray splits each layer into chunks and tracks progress with a merkle tree. Interrupted pulls resume from where they left off.

Traditional:  Layer (800MB) ------------------------> FAIL -> restart from 0

Fray:         Layer (800MB)
              +-----+-----+-----+-----+-----+-----+
              |  #  |  #  |  #  |  x  |     |     |  <- interrupt
              +-----+-----+-----+-----+-----+-----+
                                 |
                                 v resume
              +-----+-----+-----+-----+-----+-----+
              |  #  |  #  |  #  |  #  |  #  |  #  |  <- done
              +-----+-----+-----+-----+-----+-----+

Quick Start

# Install
go install github.com/hexfusion/fray/cmd/fray@latest

# Pull an image
fray pull quay.io/prometheus/busybox:latest

# Run proxy
fray proxy -l :5000 -d /var/cache/fray &
podman pull --tls-verify=false localhost:5000/docker.io/library/alpine:latest

Features

• Resumable pulls - chunk state persists across restarts
• No server changes - uses standard HTTP Range requests
• Pull-through proxy - caching registry for edge clusters
• Parallel downloads - configurable concurrency
• OCI Image Layout - standard storage format

Documentation

• User Guide - commands, options, proxy setup
• Developer Guide - architecture, building, testing
• protoc-gen-cel - CEL validation plugin for protobufs

Deployment

bootc

bootc enables transactional, image-based OS updates. Fray can be deployed as a logically bound image:

FROM quay.io/centos-bootc/centos-bootc:stream9
COPY --from=ghcr.io/hexfusion/fray:latest / /

License

Apache 2.0