moby/cli/command/service/trust.go
Aaron Lehmann d4d6f8c0d0 cli: Pin image to digest using content trust
Implement notary-based digest lookup in the client when
DOCKER_CONTENT_TRUST=1.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
2016-12-14 10:49:33 -08:00

96 lines
3.3 KiB
Go

package service
import (
"encoding/hex"
"fmt"
"github.com/Sirupsen/logrus"
"github.com/docker/distribution/digest"
distreference "github.com/docker/distribution/reference"
"github.com/docker/docker/api/types/swarm"
"github.com/docker/docker/cli/command"
"github.com/docker/docker/cli/trust"
"github.com/docker/docker/reference"
"github.com/docker/docker/registry"
"github.com/docker/notary/tuf/data"
"github.com/pkg/errors"
"golang.org/x/net/context"
)
func resolveServiceImageDigest(dockerCli *command.DockerCli, service *swarm.ServiceSpec) error {
if !command.IsTrusted() {
// Digests are resolved by the daemon when not using content
// trust.
return nil
}
image := service.TaskTemplate.ContainerSpec.Image
// We only attempt to resolve the digest if the reference
// could be parsed as a digest reference. Specifying an image ID
// is valid but not resolvable. There is no warning message for
// an image ID because it's valid to use one.
if _, err := digest.ParseDigest(image); err == nil {
return nil
}
ref, err := reference.ParseNamed(image)
if err != nil {
return fmt.Errorf("Could not parse image reference %s", service.TaskTemplate.ContainerSpec.Image)
}
if _, ok := ref.(reference.Canonical); !ok {
ref = reference.WithDefaultTag(ref)
taggedRef, ok := ref.(reference.NamedTagged)
if !ok {
// This should never happen because a reference either
// has a digest, or WithDefaultTag would give it a tag.
return errors.New("Failed to resolve image digest using content trust: reference is missing a tag")
}
resolvedImage, err := trustedResolveDigest(context.Background(), dockerCli, taggedRef)
if err != nil {
return fmt.Errorf("Failed to resolve image digest using content trust: %v", err)
}
logrus.Debugf("resolved image tag to %s using content trust", resolvedImage.String())
service.TaskTemplate.ContainerSpec.Image = resolvedImage.String()
}
return nil
}
func trustedResolveDigest(ctx context.Context, cli *command.DockerCli, ref reference.NamedTagged) (distreference.Canonical, error) {
repoInfo, err := registry.ParseRepositoryInfo(ref)
if err != nil {
return nil, err
}
authConfig := command.ResolveAuthConfig(ctx, cli, repoInfo.Index)
notaryRepo, err := trust.GetNotaryRepository(cli, repoInfo, authConfig, "pull")
if err != nil {
return nil, errors.Wrap(err, "error establishing connection to trust repository")
}
t, err := notaryRepo.GetTargetByName(ref.Tag(), trust.ReleasesRole, data.CanonicalTargetsRole)
if err != nil {
return nil, trust.NotaryError(repoInfo.FullName(), err)
}
// Only get the tag if it's in the top level targets role or the releases delegation role
// ignore it if it's in any other delegation roles
if t.Role != trust.ReleasesRole && t.Role != data.CanonicalTargetsRole {
return nil, trust.NotaryError(repoInfo.FullName(), fmt.Errorf("No trust data for %s", ref.String()))
}
logrus.Debugf("retrieving target for %s role\n", t.Role)
h, ok := t.Hashes["sha256"]
if !ok {
return nil, errors.New("no valid hash, expecting sha256")
}
dgst := digest.NewDigestFromHex("sha256", hex.EncodeToString(h))
// Using distribution reference package to make sure that adding a
// digest does not erase the tag. When the two reference packages
// are unified, this will no longer be an issue.
return distreference.WithDigest(ref, dgst)
}