feat(push): stub for 'image push' command and Dialer interface for cluster connectors

cmd/uncloud/image/push.go

@@ -0,0 +1,47 @@
+package image
+
+import (
+	"fmt"
+
+	"github.com/psviderski/uncloud/internal/cli"
+	"github.com/spf13/cobra"
+)
+
+type pushOptions struct {
+	machines []string
+}
+
+func NewPushCommand() *cobra.Command {
+	opts := pushOptions{}
+
+	cmd := &cobra.Command{
+		Use:   "push IMAGE",
+		Short: "Upload a local Docker image to the cluster.",
+		Long: `Upload a local Docker image to the cluster transferring only the missing layers.
+The image is uploaded to the machine which CLI is connected to (default) or the specified machine(s).`,
+		Example: `  # Push image to the currently connected machine.
+  uc image push myapp:latest
+
+  # Push image to specific machine.
+  uc image push myapp:latest -m machine1
+
+  # Push image to multiple machines.
+  uc image push myapp:latest -m machine1,machine2,machine3`,
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			image := args[0]
+
+			machines := cli.ExpandCommaSeparatedValues(opts.machines)
+
+			// TODO: Implement image push logic
+			fmt.Printf("Would push image %q to machines: %v\n", image, machines)
+			return fmt.Errorf("image push not yet implemented")
+		},
+	}
+
+	cmd.Flags().StringSliceVarP(&opts.machines, "machine", "m", nil,
+		"Machine names to push the image to. Can be specified multiple times or as a comma-separated "+
+			"list of machine names. (default is connected machine)")
+
+	return cmd
+}

cmd/uncloud/image/root.go

@@ -0,0 +1,18 @@
+package image
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func NewRootCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "image",
+		Short: "Manage Docker images in a cluster.",
+	}
+
+	cmd.AddCommand(
+		NewPushCommand(),
+	)
+
+	return cmd
+}

cmd/uncloud/main.go

@@ -9,6 +9,7 @@ import (
 	"github.com/psviderski/uncloud/cmd/uncloud/caddy"
 	cmdcontext "github.com/psviderski/uncloud/cmd/uncloud/context"
 	"github.com/psviderski/uncloud/cmd/uncloud/dns"
+	"github.com/psviderski/uncloud/cmd/uncloud/image"
 	"github.com/psviderski/uncloud/cmd/uncloud/machine"
 	"github.com/psviderski/uncloud/cmd/uncloud/service"
 	"github.com/psviderski/uncloud/cmd/uncloud/volume"
@@ -82,6 +83,7 @@ func main() {
 		caddy.NewRootCommand(),
 		cmdcontext.NewRootCommand(),
 		dns.NewRootCommand(),
+		image.NewRootCommand(),
 		machine.NewRootCommand(),
 		service.NewRootCommand(),
 		service.NewInspectCommand(),

pkg/client/client.go

@@ -10,6 +10,7 @@ import (
 	"github.com/psviderski/uncloud/internal/machine/api/pb"
 	"github.com/psviderski/uncloud/internal/machine/docker"
 	"github.com/psviderski/uncloud/pkg/api"
+	"golang.org/x/net/proxy"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/metadata"
 )
@@ -31,9 +32,12 @@ type Client struct {
 
 var _ api.Client = (*Client)(nil)
 
-// Connector is an interface for establishing a connection to the machine API.
+// Connector is an interface for establishing a connection to the cluster.
 type Connector interface {
+	// Connect establishes a gRPC client connection to the machine API.
 	Connect(ctx context.Context) (*grpc.ClientConn, error)
+	// Dialer returns a proxy dialer for establishing connections within the cluster if supported by the connector.
+	Dialer() (proxy.ContextDialer, error)
 	Close() error
 }
 

pkg/client/connector/ssh.go

@@ -9,6 +9,7 @@ import (
 	"github.com/psviderski/uncloud/internal/machine"
 	"github.com/psviderski/uncloud/internal/sshexec"
 	"golang.org/x/crypto/ssh"
+	"golang.org/x/net/proxy"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 )
@@ -79,6 +80,10 @@ func (c *SSHConnector) Connect(ctx context.Context) (*grpc.ClientConn, error) {
 	return conn, nil
 }
 
+func (c *SSHConnector) Dialer() (proxy.ContextDialer, error) {
+	return nil, fmt.Errorf("dialer not implemented for SSHConnector yet")
+}
+
 func (c *SSHConnector) Close() error {
 	if c.client != nil {
 		err := c.client.Close()

pkg/client/connector/tcp.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/netip"
 
+	"golang.org/x/net/proxy"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 )
@@ -29,6 +30,10 @@ func (c *TCPConnector) Connect(_ context.Context) (*grpc.ClientConn, error) {
 	return conn, nil
 }
 
+func (c *TCPConnector) Dialer() (proxy.ContextDialer, error) {
+	return nil, fmt.Errorf("proxy connections are not supported over a TCP connection")
+}
+
 func (c *TCPConnector) Close() error {
 	return nil
 }

pkg/client/connector/wireguard.go

@@ -12,6 +12,7 @@ import (
 	"github.com/psviderski/uncloud/internal/machine/network"
 	"github.com/psviderski/uncloud/internal/machine/network/tunnel"
 	"github.com/psviderski/uncloud/pkg/client"
+	"golang.org/x/net/proxy"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 )
@@ -75,6 +76,10 @@ func (c *WireGuardConnector) Connect(ctx context.Context) (*grpc.ClientConn, err
 	return conn, nil
 }
 
+func (c *WireGuardConnector) Dialer() (proxy.ContextDialer, error) {
+	return nil, fmt.Errorf("proxy connections not implemented for WireGuard connector")
+}
+
 func (c *WireGuardConnector) Close() error {
 	if c.tun != nil {
 		c.tun.Close()