Registries are evolving as Cloud Native Artifact Stores. To enable this goal, Microsoft has donated ORAS as means to enable various client libraries with a way to submit artifacts to OCI Spec Compliant registires. This repo is a staging ground for some yet to be determined upstream home.
As of Jan 24th, 2019, we're still evolving the library to incorporate annotation support. While we're initially testing ORAS with Helm 3 Registries and CNAB, we're very interested in feedback and contributions for other artifacts.
Want to reach the ORAS community and developers? Join us in the CNCF Slack #oras channel
For more background, please see:
- OCI Image Support Comes to Open Source Docker Registry
- Registries are evolving as Cloud Native Artifact Stores
oras can push/pull any files to/from any registry with OCI image support of various mime types.
- Distribution (open source, version 2.7+)
- Azure Container Registry
- Quay.io is coming soon
First, you must have access to a registry with OCI image support (see list above).
The simplest way to get started is to run the official Docker registry image locally:
docker run -it --rm -p 5000:5000 registry
This will start a Distribution server at localhost:5000
(with wide-open access and no persistence).
Next, install the oras CLI (see platform-specific installation instructions below).
Push a sample file to the registry:
cd /tmp && echo "hello world" > hi.txt
oras push localhost:5000/hello:latest hi.txt
Pull the file from the registry:
cd /tmp && rm -f hi.txt
oras pull localhost:5000/hello:latest
cat hi.txt # should print "hello world"
Please see the Go Module section below for how this can be imported and used inside a Go project.
oras is a CLI that allows you to push and pull files from
any registry with OCI image support.
Install oras using GoFish:
gofish install oras
==> Installing oras...
🐠 oras 0.5.0: installed in 65.131245ms
or install manually from the latest release artifacts:
# Linux
curl -LO https://github.com/deislabs/oras/releases/download/v0.5.0/oras_0.5.0_linux_amd64.tar.gz
# macOS
curl -LO https://github.com/deislabs/oras/releases/download/v0.5.0/oras_0.5.0_darwin_amd64.tar.gz
# unpack, install, dispose
mkdir -p oras-install/
tar -zxf oras_0.5.0_*.tar.gz -C oras-install/
mv oras-install/oras /usr/local/bin/
rm -rf oras_0.5.0_*.tar.gz oras-install/
Then, to run:
oras help
A public Docker image containing the CLI is available on Docker Hub:
docker run -it --rm -v $(pwd):/workspace orasbot/oras:v0.5.0 help
Note: the default WORKDIR in the image is /workspace.
Run oras login in advance for any private registries. By default, this will store credentials in ~/.docker/config.json (same file as used by Docker). If you have authenticated to a registry previously using docker login, the credentials will be reused. Use the -c/--config option to specify an alternate location.
oras also accepts explicit credentials via options, for example,
oras pull -u username -p password myregistry.io/myimage:latest
First, create a valid htpasswd file (must use -B for bcrypt):
htpasswd -cB -b auth.htpasswd myuser mypass
Next, start a registry using that file for auth:
docker run -it --rm -p 5000:5000 \
-v $(pwd)/auth.htpasswd:/etc/docker/registry/auth.htpasswd \
-e REGISTRY_AUTH="{htpasswd: {realm: localhost, path: /etc/docker/registry/auth.htpasswd}}" \
registry
In a new window, login with oras:
oras login -u myuser -p mypass localhost:5000
You will notice a new entry for localhost:5000 appear in ~/.docker/config.json.
To remove the entry from the credentials file, use oras logout:
oras logout localhost:5000
oras push localhost:5000/hello:latest hi.txt
The default media type for all files is application/vnd.oci.image.layer.v1.tar.
The push a custom media type, use the format filename[:type]:
oras push localhost:5000/hello:latest hi.txt:application/vnd.me.hi
Just as docker images support multiple "layers", ORAS supports pushing multiple files. The file type is up to the implementer. You can push tar, yaml, text or whatever your artifact should be represented as.
To push multiple files with different media types:
oras push localhost:5000/hello:latest hi.txt:application/vnd.me.hi bye.txt:application/vnd.me.bye
oras pull localhost:5000/hello:latest
By default, only blobs with media type application/vnd.oci.image.layer.v1.tar will be downloaded.
To specify which media types to download, use the --media-type/-t flag:
oras pull localhost:5000/hello:latest -t application/vnd.me.hi
Or to allow all media types, use the --allow-all/-a flag:
oras pull localhost:5000/hello:latest -a
The package github.com/deislabs/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:
package main
import (
"context"
"fmt"
"github.com/deislabs/oras/pkg/content"
"github.com/deislabs/oras/pkg/oras"
"github.com/containerd/containerd/remotes/docker"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
)
func check(e error) {
if e != nil {
panic(e)
}
}
func main() {
ref := "localhost:5000/oras:test"
fileName := "hello.txt"
fileContent := []byte("Hello World!\n")
customMediaType := "my.custom.media.type"
ctx := context.Background()
resolver := docker.NewResolver(docker.ResolverOptions{})
// Push file(s) w custom mediatype to registry
memoryStore := content.NewMemoryStore()
desc := memoryStore.Add(fileName, customMediaType, fileContent)
pushContents := []ocispec.Descriptor{desc}
fmt.Printf("Pushing %s to %s...\n", fileName, ref)
desc, err := oras.Push(ctx, resolver, ref, memoryStore, pushContents)
check(err)
fmt.Printf("Pushed to %s with digest %s\n", ref, desc.Digest)
// Pull file(s) from registry and save to disk
fmt.Printf("Pulling from %s and saving to %s...\n", ref, fileName)
fileStore := content.NewFileStore("")
defer fileStore.Close()
allowedMediaTypes := []string{customMediaType}
desc, _, err = oras.Pull(ctx, resolver, ref, fileStore, oras.WithAllowedMediaTypes(allowedMediaTypes))
check(err)
fmt.Printf("Pulled from %s with digest %s\n", ref, desc.Digest)
fmt.Printf("Try running 'cat %s'\n", fileName)
}