Copy container image with google/go-containerregistry

An example of copying docker image, with simple username password, between two registries with crane.

TL,DR

Use multiple keychain and implement KeyChain interface

func (obj MyOjbect) Resolve(target authn.Resource) (authn.Authenticator, error) {
	reg := target.RegistryStr()
	if strings.Contains(src url, reg) {
		return &authn.Basic{
			Username: src username,
			Password: src password,
		}, nil
	} else {
		return &authn.Basic{
			Username: dest username,
			Password: dest password,
		}, nil
	}
}

func main() {
    	_ = crane.Copy(src url, dest url, crane.WithAuthFromKeychain(obj))
}

Credits

• authn readme: google/go-containerregistry/pkg/authn
• Exmaple of copying to AWS ECR with helper: ekirmayer/aws-lambda-copy-container-image-to-ecr