fix: use local and remote Docker credentials to pull image from private registry

pkg/client/container.go

@@ -4,12 +4,17 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"strings"
 
+	dockercommand "github.com/docker/cli/cli/command"
+	dockerconfig "github.com/docker/cli/cli/config"
 	"github.com/docker/compose/v2/pkg/progress"
 	"github.com/docker/docker/api/types/container"
+	"github.com/docker/docker/api/types/registry"
 	dockerclient "github.com/docker/docker/client"
 	"github.com/docker/docker/pkg/jsonmessage"
+	"github.com/psviderski/uncloud/internal/machine/docker"
 	"github.com/psviderski/uncloud/internal/secret"
 	"github.com/psviderski/uncloud/pkg/api"
 	"google.golang.org/grpc/status"
@@ -89,7 +94,14 @@ func (cli *Client) pullImageWithProgress(ctx context.Context, image, machineName
 		StatusText: "Pulling",
 	})
 
-	pullCh, err := cli.Docker.PullImage(ctx, image)
+	opts := docker.PullOptions{}
+	// Try to retrieve the authentication token for the image from the default local Docker config file.
+	if encodedAuth, err := retrieveRegistryAuthFromDocker(image); err == nil && encodedAuth != "" {
+		// If RegistryAuth is empty, Uncloud daemon will try to retrieve the credentials from its own Docker config.
+		opts.RegistryAuth = encodedAuth
+	}
+
+	pullCh, err := cli.Docker.PullImage(ctx, image, opts)
 	if err != nil {
 		statusErr := status.Convert(err)
 		pw.Event(progress.Event{
@@ -143,6 +155,34 @@ func (cli *Client) pullImageWithProgress(ctx context.Context, image, machineName
 	return nil
 }
 
+// retrieveRegistryAuthFromDocker retrieves the authentication token for the specified image from the local Docker
+// config file. It returns the encoded authentication token if it contains any credentials, or an empty string if
+// no credentials are found.
+func retrieveRegistryAuthFromDocker(image string) (string, error) {
+	// Try to retrieve the authentication token for the image from the default local Docker config file.
+	dockerConfig := dockerconfig.LoadDefaultConfigFile(os.Stderr)
+	encodedAuth, err := dockercommand.RetrieveAuthTokenFromImage(dockerConfig, image)
+	if err != nil {
+		return "", err
+	}
+	// The encodedAuth can be a base64-encoded "{}" (empty JSON object) or include a server address but no credentials.
+	// Return encodedAuth only if it contains any credentials.
+	auth, err := registry.DecodeAuthConfig(encodedAuth)
+	if err != nil {
+		return "", fmt.Errorf("decode auth config: %w", err)
+	}
+
+	if auth.Username == "" &&
+		auth.Password == "" &&
+		auth.Auth == "" &&
+		auth.IdentityToken == "" &&
+		auth.RegistryToken == "" {
+		return "", nil
+	}
+
+	return encodedAuth, nil
+}
+
 // toPullProgressEvent converts a JSON progress message from the Docker API to a progress event.
 // It's based on toPullProgressEvent from Docker Compose.
 func toPullProgressEvent(jm jsonmessage.JSONMessage) *progress.Event {