Files
buildx/builder/node.go
Tonis Tiigi acaf251f0b policy: verify BuildKit builder images
Extend the built-in policy to validate signed moby/buildkit release and
floating tags before docker-container builders are created.

Pull the image first, inspect it through Docker, and bind verification to the
descriptor digest. Resolve signature attestations through the BuildKit API
embedded in the Docker daemon.

If pulling fails, use a local image while applying the same verification when
the containerd image store exposes an immutable descriptor. Keep the classic
image-store behavior unchanged because no descriptor is available.

Allow unmanaged repositories and digest-only references unchanged. Add the
allow-untrusted-image driver option as an explicit verification bypass.

Document the behavior and add policy, digest-pinning, and local fallback
coverage.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
2026-07-20 18:22:41 -07:00

309 lines
7.8 KiB
Go

package builder
import (
"context"
"encoding/json"
"sort"
"strings"
"github.com/containerd/platforms"
"github.com/docker/buildx/driver"
"github.com/docker/buildx/policy"
"github.com/docker/buildx/store"
"github.com/docker/buildx/store/storeutil"
"github.com/docker/buildx/util/confutil"
"github.com/docker/buildx/util/dockerutil"
"github.com/docker/buildx/util/imagetools"
"github.com/docker/buildx/util/platformutil"
"github.com/moby/buildkit/client"
"github.com/moby/buildkit/util/grpcerrors"
digest "github.com/opencontainers/go-digest"
ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"golang.org/x/sync/errgroup"
"google.golang.org/grpc/codes"
)
type Node struct {
store.Node
Builder string
Driver *driver.DriverHandle
DriverInfo *driver.Info
ImageOpt imagetools.Opt
ProxyConfig map[string]string
Version string
Err error
// worker settings
IDs []string
Platforms []ocispecs.Platform
GCPolicy []client.PruneInfo
Labels map[string]string
CDIDevices []client.CDIDevice
}
// Nodes returns nodes for this builder.
func (b *Builder) Nodes() []Node {
return b.nodes
}
type LoadNodesOption func(*loadNodesOptions)
type loadNodesOptions struct {
data bool
skipImageOpt bool
dialMeta map[string][]string
clientOpt []client.ClientOpt
}
func WithData() LoadNodesOption {
return func(o *loadNodesOptions) {
o.data = true
}
}
func WithSkippedImageOpt() LoadNodesOption {
return func(o *loadNodesOptions) {
o.skipImageOpt = true
}
}
func WithDialMeta(dialMeta map[string][]string) LoadNodesOption {
return func(o *loadNodesOptions) {
o.dialMeta = dialMeta
}
}
func WithClientOpt(clientOpt ...client.ClientOpt) LoadNodesOption {
return func(o *loadNodesOptions) {
o.clientOpt = clientOpt
}
}
// LoadNodes loads and returns nodes for this builder.
// TODO: this should be a method on a Node object and lazy load data for each driver.
func (b *Builder) LoadNodes(ctx context.Context, opts ...LoadNodesOption) (_ []Node, err error) {
lno := loadNodesOptions{
data: false,
}
for _, opt := range opts {
opt(&lno)
}
eg, _ := errgroup.WithContext(ctx)
b.nodes = make([]Node, len(b.NodeGroup.Nodes))
defer func() {
if b.err == nil && err != nil {
b.err = err
}
}()
factory, err := b.Factory(ctx, lno.dialMeta)
if err != nil {
return nil, err
}
var imageopt imagetools.Opt
if !lno.skipImageOpt {
imageopt, err = b.ImageOpt()
if err != nil {
return nil, err
}
}
var imageVerifier driver.ImageVerifier
if policy.DefaultPolicyEnabled() {
pol := policy.DefaultPolicy(policy.Opt{
Log: func(_ logrus.Level, msg string) {
logrus.Debug(msg)
},
VerifierProvider: policy.SignatureVerifier(confutil.NewConfig(b.opts.dockerCli)),
})
imageVerifier = func(ctx context.Context, ref string, platform *ocispecs.Platform, resolver policy.SourceMetadataResolver) (digest.Digest, error) {
return pol.CheckSource(ctx, ref, platform, resolver)
}
}
for i, n := range b.NodeGroup.Nodes {
func(i int, n store.Node) {
eg.Go(func() error {
node := Node{
Node: n,
ProxyConfig: storeutil.GetProxyConfig(b.opts.dockerCli),
Platforms: n.Platforms,
Builder: b.Name,
}
defer func() {
b.nodes[i] = node
}()
dockerapi, err := dockerutil.NewClientAPI(b.opts.dockerCli, n.Endpoint)
if err != nil {
node.Err = err
return nil
}
d, err := driver.GetDriver(ctx, factory, driver.InitConfig{
Name: driver.BuilderName(n.Name),
EndpointAddr: n.Endpoint,
DockerAPI: dockerapi,
ContextStore: b.opts.dockerCli.ContextStore(),
BuildkitdFlags: n.BuildkitdFlags,
Files: n.Files,
DriverOpts: n.DriverOpts,
Auth: imageopt.Auth,
ImageVerifier: imageVerifier,
Platforms: n.Platforms,
ContextPathHash: b.opts.contextPathHash,
DialMeta: lno.dialMeta,
})
if err != nil {
node.Err = err
return nil
}
node.Driver = d
node.ImageOpt = imageopt
if lno.data {
if err := node.loadData(ctx, lno.clientOpt...); err != nil {
node.Err = err
}
}
return nil
})
}(i, n)
}
if err := eg.Wait(); err != nil {
return nil, err
}
// TODO: This should be done in the routine loading driver data
if lno.data {
kubernetesDriverCount := 0
for _, d := range b.nodes {
if d.DriverInfo != nil && len(d.DriverInfo.DynamicNodes) > 0 {
kubernetesDriverCount++
}
}
isAllKubernetesDrivers := len(b.nodes) == kubernetesDriverCount
if isAllKubernetesDrivers {
var nodes []Node
var dynamicNodes []store.Node
for _, di := range b.nodes {
// dynamic nodes are used in Kubernetes driver.
// Kubernetes' pods are dynamically mapped to BuildKit Nodes.
if di.DriverInfo != nil && len(di.DriverInfo.DynamicNodes) > 0 {
for i := range di.DriverInfo.DynamicNodes {
diClone := di
if pl := di.DriverInfo.DynamicNodes[i].Platforms; len(pl) > 0 {
diClone.Platforms = pl
}
nodes = append(nodes, diClone)
}
dynamicNodes = append(dynamicNodes, di.DriverInfo.DynamicNodes...)
}
}
// not append (remove the static nodes in the store)
b.NodeGroup.Nodes = dynamicNodes
b.nodes = nodes
b.Dynamic = true
}
}
return b.nodes, nil
}
func (n *Node) MarshalJSON() ([]byte, error) {
var status string
if n.DriverInfo != nil {
status = n.DriverInfo.Status.String()
}
var nerr string
if n.Err != nil {
status = "error"
nerr = strings.TrimSpace(n.Err.Error())
}
var pp []string
for _, p := range n.Platforms {
pp = append(pp, platforms.Format(p))
}
return json.Marshal(struct {
Name string
Endpoint string
BuildkitdFlags []string `json:"Flags,omitempty"`
DriverOpts map[string]string `json:",omitempty"`
Files map[string][]byte `json:",omitempty"`
Status string `json:",omitempty"`
ProxyConfig map[string]string `json:",omitempty"`
Version string `json:",omitempty"`
Err string `json:",omitempty"`
IDs []string `json:",omitempty"`
Platforms []string `json:",omitempty"`
GCPolicy []client.PruneInfo `json:",omitempty"`
Labels map[string]string `json:",omitempty"`
}{
Name: n.Name,
Endpoint: n.Endpoint,
BuildkitdFlags: n.BuildkitdFlags,
DriverOpts: n.DriverOpts,
Files: n.Files,
Status: status,
ProxyConfig: n.ProxyConfig,
Version: n.Version,
Err: nerr,
IDs: n.IDs,
Platforms: pp,
GCPolicy: n.GCPolicy,
Labels: n.Labels,
})
}
func (n *Node) loadData(ctx context.Context, clientOpt ...client.ClientOpt) error {
if n.Driver == nil {
return nil
}
info, err := n.Driver.Info(ctx)
if err != nil {
return err
}
n.DriverInfo = info
if n.DriverInfo.Status == driver.Running {
driverClient, err := n.Driver.Client(ctx, clientOpt...)
if err != nil {
return err
}
workers, err := driverClient.ListWorkers(ctx)
if err != nil {
return errors.Wrap(err, "listing workers")
}
for idx, w := range workers {
n.IDs = append(n.IDs, w.ID)
n.Platforms = append(n.Platforms, w.Platforms...)
if idx == 0 {
n.GCPolicy = w.GCPolicy
n.Labels = w.Labels
}
n.CDIDevices = w.CDIDevices
}
sort.Strings(n.IDs)
n.Platforms = platformutil.Dedupe(n.Platforms)
inf, err := driverClient.Info(ctx)
if err != nil {
if st, ok := grpcerrors.AsGRPCStatus(err); ok && st.Code() == codes.Unimplemented {
n.Version, err = n.Driver.Version(ctx)
if err != nil {
return errors.Wrap(err, "getting version")
}
}
} else {
n.Version = inf.BuildkitVersion.Version
}
}
return nil
}