imagetools: support registrytoken auth in docker config

This is not supported by the Authorizer from containerd and
needs to be added manually. Build authentication happens through
BuildKit session that already supports this.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

util/imagetools/auth.go

@@ -1,28 +1,70 @@
 package imagetools
 
 import (
+	"context"
 	"encoding/base64"
 	"encoding/json"
+	"net/http"
+	"sync"
+	"time"
 
+	"github.com/containerd/containerd/v2/core/remotes/docker"
 	"github.com/distribution/reference"
+	"github.com/docker/cli/cli/config/types"
 )
 
-func toCredentialsFunc(a Auth) func(string) (string, string, error) {
-	return func(host string) (string, string, error) {
-		if host == "registry-1.docker.io" {
-			host = "https://index.docker.io/v1/"
-		}
-		ac, err := a.GetAuthConfig(host)
-		if err != nil {
-			return "", "", err
-		}
-		if ac.IdentityToken != "" {
-			return "", ac.IdentityToken, nil
-		}
-		return ac.Username, ac.Password, nil
+type authConfig struct {
+	mu              sync.Mutex
+	authConfigCache map[string]authConfigCacheEntry
+	cfg             Auth
+}
+
+type authConfigCacheEntry struct {
+	Created time.Time
+	Auth    types.AuthConfig
+}
+
+func newAuthConfig(a Auth) *authConfig {
+	return &authConfig{
+		authConfigCache: map[string]authConfigCacheEntry{},
+		cfg:             a,
 	}
 }
 
+func (a *authConfig) credentials(host string) (string, string, error) {
+	ac, err := a.authConfig(host)
+	if err != nil {
+		return "", "", err
+	}
+	if ac.IdentityToken != "" {
+		return "", ac.IdentityToken, nil
+	}
+	return ac.Username, ac.Password, nil
+}
+
+func (a *authConfig) authConfig(host string) (types.AuthConfig, error) {
+	const defaultExpiration = 2 * time.Minute
+
+	if host == "registry-1.docker.io" {
+		host = "https://index.docker.io/v1/"
+	}
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	if c, ok := a.authConfigCache[host]; ok && time.Since(c.Created) <= defaultExpiration {
+		return c.Auth, nil
+	}
+	ac, err := a.cfg.GetAuthConfig(host)
+	if err != nil {
+		return types.AuthConfig{}, err
+	}
+	a.authConfigCache[host] = authConfigCacheEntry{
+		Created: time.Now(),
+		Auth:    ac,
+	}
+	return ac, nil
+}
+
 func RegistryAuthForRef(ref string, a Auth) (string, error) {
 	if a == nil {
 		return "", nil
@@ -45,3 +87,17 @@ func RegistryAuthForRef(ref string, a Auth) (string, error) {
 	}
 	return base64.URLEncoding.EncodeToString(buf), nil
 }
+
+type withBearerAuthorizer struct {
+	docker.Authorizer
+	AuthConfig *authConfig
+}
+
+func (a *withBearerAuthorizer) Authorize(ctx context.Context, req *http.Request) error {
+	ac, err := a.AuthConfig.authConfig(req.Host)
+	if err == nil && ac.RegistryToken != "" {
+		req.Header.Set("Authorization", "Bearer "+ac.RegistryToken)
+		return nil
+	}
+	return a.Authorizer.Authorize(ctx, req)
+}

util/imagetools/inspect.go

@@ -34,8 +34,14 @@ type Resolver struct {
 }
 
 func New(opt Opt) *Resolver {
+	ac := newAuthConfig(opt.Auth)
+	dockerAuth := docker.NewDockerAuthorizer(docker.WithAuthCreds(ac.credentials), docker.WithAuthClient(http.DefaultClient))
+	auth := &withBearerAuthorizer{
+		Authorizer: dockerAuth,
+		AuthConfig: ac,
+	}
 	return &Resolver{
-		auth:   docker.NewDockerAuthorizer(docker.WithAuthCreds(toCredentialsFunc(opt.Auth)), docker.WithAuthClient(http.DefaultClient)),
+		auth:   auth,
 		hosts:  resolver.NewRegistryConfig(opt.RegistryConfig),
 		buffer: contentutil.NewBuffer(),
 	}