feat: add support for ecr, gcp, acr authn

pkg/oci/types.go

@@ -4,9 +4,12 @@ import (
 	"fmt"
 	"log"
 
+	ecr "github.com/awslabs/amazon-ecr-credential-helper/ecr-login"
+	acr "github.com/chrismellard/docker-credential-acr-env/pkg/credhelper"
 	"github.com/google/go-containerregistry/pkg/authn"
 	"github.com/google/go-containerregistry/pkg/name"
 	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/google"
 	"github.com/google/go-containerregistry/pkg/v1/layout"
 	"github.com/google/go-containerregistry/pkg/v1/remote"
 )
@@ -50,13 +53,15 @@ func SubjectIndexFromRemote(image string) (*SubjectIndex, error) {
 	if err != nil {
 		log.Fatalf("Failed to parse image name: %v", err)
 	}
-	// Get the authenticator from the default Docker keychain
-	auth, err := authn.DefaultKeychain.Resolve(ref.Context())
-	if err != nil {
-		log.Fatalf("Failed to get authenticator: %v", err)
-	}
+	// Create a multi-keychain that will use the default Docker, Google, ECR or ACR keychain
+	keychain := authn.NewMultiKeychain(
+		authn.DefaultKeychain,
+		google.Keychain,
+		authn.NewKeychainFromHelper(ecr.NewECRHelper()),
+		authn.NewKeychainFromHelper(acr.NewACRCredentialsHelper()),
+	)
 	// Pull the image from the registry
-	idx, err := remote.Index(ref, remote.WithAuth(auth))
+	idx, err := remote.Index(ref, remote.WithAuthFromKeychain(keychain))
 	if err != nil {
 		return nil, fmt.Errorf("failed to pull image %s: %w", image, err)
 	}