OCI Registry As Storage

oras can push/pull any files from/to any registry with OCI image support.

Registries with known support:

• Distribution (open source, version 2.7+)
• Azure Container Registry

For more backgound on this topic, please see this post.

CLI

oras is a CLI that allows you to push and pull files from any registry with OCI image support.

Installation

Install from latest release (v0.1.0):

# on Linux
curl -LO https://github.com/shizhMSFT/oras/releases/download/v0.1.0/oras_0.1.0_linux_amd64.tar.gz

# on macOS
curl -LO https://github.com/shizhMSFT/oras/releases/download/v0.1.0/oras_0.1.0_darwin_amd64.tar.gz

# on Windows
curl -LO https://github.com/shizhMSFT/oras/releases/download/v0.1.0/oras_0.1.0_linux_amd64.tar.gz

mkdir -p oras/
tar -zxf oras_0.1.0_*.tar.gz -C oras/
mv oras/bin/oras /usr/local/bin/
rm -rf oras_0.1.0_*.tar.gz oras/

The checksums for the .tar.gz files can be found here.

Push files to remote registry

oras push localhost:5000/hello:latest hello.txt

Pull files from remote registry

oras pull localhost:5000/hello:latest

Login Credentials

oras uses the local docker credential by default. Therefore, please run docker login in advance for any private registries.

oras also accepts explicit credentials via options. For example,

oras pull -u username -p password myregistry.io/myimage:latest

Running in Docker

Build the image

docker build -t oras .

Run on Linux

docker run --rm -it -v $(pwd):/workplace oras pull localhost:5000/hello:latest

Run on Windows PowerShell

docker run --rm -it -v ${pwd}:/workplace oras pull localhost:5000/hello:latest

Run on Windows Commands

docker run --rm -it -v %cd%:/workplace oras pull localhost:5000/hello:latest

Go Module

The package github.com/shizhMSFT/oras/pkg/oras can quickly be imported in other Go-based tools that wish to benefit from the ability to store arbitrary content in container registries.

Example:

Source

package main

import (
	"context"
	"fmt"
	"github.com/containerd/containerd/remotes/docker"
	"github.com/shizhMSFT/oras/pkg/oras"
	"io/ioutil"
)

func check(e error) {
	if e != nil {
		panic(e)
	}
}

func main() {
	ref := "localhost:5000/oras:test"
	fileName := "hello.txt"
	fileContent := []byte("Hello World!\n")

	ctx := context.Background()
	resolver := docker.NewResolver(docker.ResolverOptions{})

	// Push file(s) to registry
	pushContents := make(map[string][]byte)
	pushContents[fileName] = fileContent
	fmt.Printf("Pushing %s to %s... ", fileName, ref)
	err := oras.Push(ctx, resolver, ref, pushContents)
	check(err)
	fmt.Println("success!")

	// Pull file(s) from registry and save to disk
	fmt.Printf("Pulling from %s and saving to %s... ", ref, fileName)
	pullContents, err := oras.Pull(ctx, resolver, ref)
	check(err)
	err = ioutil.WriteFile(fileName, pullContents[fileName], 0644)
	check(err)
	fmt.Println("success!")
	fmt.Printf("Try running 'cat %s'\n", fileName)
}